Destratification – What is it ?

Destratification – What is it ?

Destratification and how destratification systems reduce the inefficiency of a warm air heating system by mixing the layers of air to ensure higher energy efficiency as recommended by the carbon trust in the UK.

Destratification- What is it ?

 

Destratification is the opposite of the natural process of thermal stratification in HVAC systems, which is the layering of different (usually increasing) air temperatures from floor to ceiling. Thermal stratification occurs when heated air rises to the ceiling or roof space or area because it is lighter than the colder air around it. Cooler air, on the other hand, descends to the floor level because it is heavier than the warmer air around it.

Its basic principles of physics really –as this surrounding cooler air falls to the floor level, and the hot air rises, this is the reverse of what we require when heating. We need to send that heat back down to where it is required, to heat the staff or customers of your business, thus reducing energy consumption and lower energy costs and this is where a destratification system solves this problem by using destratification fans.

Destratification technology can also be used on cooled air supplied by air conditioning systems by ensuring that the chilled air is properly mixing, circulated, and distributed equally throughout the building volume.

What is destratification, and how does stratification make it more difficult to keep the temperature constant?

Here we explore the issues of stratified air which is caused by hot air rising up to the roof space or ceiling level.

How does thermal stratification impact our living and working environments, and what is destratification?

This simple yet important law of nature can pose serious challenges to businesses trying to keep their buildings at consistent temperatures for their clients, employees, and inventory. Heating and cooling systems that are not efficient can be expensive and wasteful. Variations in air temperature can have a significant impact on both the working environment of personnel and the shopping experience. Some may be moaning about the heat in one location while others will be too cold, i.e., hot and cold spots.

In temperature-regulated storage facilities where consistent temperatures are necessary, temperature variations can also seriously affect the design of racking systems. This is particularly true in refrigerated storage facilities, where the cold temperatures are necessary to ensure the commodities’ quality and longevity. Many kinds of commodities’ “shelf life” might be impacted by excessively hot or cold storage conditions.

Thermal stratification

The development of “thermal stratification,” or naturally occurring thermodynamic layers, is the cause of the issue. Warm air rises naturally because it is lighter than cold air. To put it another way, cold air is heavier and denser than warm air. The warmer air is forced upward because the heavier object lowers. Thermal stratification is the result, which is a growing gradient of temperatures from the warmest at the top to the coldest at the bottom. It’s possible that many buildings lack high-quality ventilation systems because naturally, hotter layers develop at ceiling level while cooler layers remain at ground level. Thermal stratification can be more problematic in larger, more open spaces.

Benefits of destratification by Flexiheat UK

Open, high ceilings are common in commercial, industrial, and retail facilities, allowing tenants to arrange the space to best fit their needs. Mezzanine floors are prevalent. They are widely used to divide up employee workspaces and identify the various departments inside the company. The significant temperature variations between the various parts of the structure can make this type of space use problematic.

Temperature difference of the air

The “strata,” or ceiling temperature layers, of buildings taller than four metres differ from those at ground level, where standard thermostats are typically installed. Depending on the architecture and design, the temperature differential between the strata may be significant. A building is more prone to experience problems with thermal stratification the higher and more open it is.

Destratification fan systems can be advantageous in this situation. Effective and efficient heating and/or cooling of buildings calls for a tailored solution with a destratification fan or destratification fans ensuring air movement to eliminate air stratification.

Systems for destratification are intended to increase airflow in an area. Strong targeted destratification fans force the warmer air back down from the roof space to the floor area and prevent the temperature stratification by continuously mixing all the air in the building and reducing the temperature difference between the ceiling and floor. Because of this constant airflow recirculation, any extra heat produced by processes, people, or even solar gain ensures all air temperatures are blended equally and reduce the temperature gradient and lower energy costs for your building.

As a result, the temperature stays more consistent throughout. This lowers the energy consumed and thus the energy bills and makes it simpler to keep all your clients and staff at suitable working temperatures.

The benefits of thermal destratification systems

The benefits of thermal destratification systems are clear:

1.A 20% to 40% decrease in heating bills depending on ceiling heights – i.e., the higher the ceiling height, the larger energy savings.

2.Reduced carbon emissions / footprint – the less energy consumption the less carbon dioxide emissions occur

3. More comfortable environment for your customers or staff as you can maintain a even heating temperature within your building.

4.During the summer, destratification fans can also be employed to create cooling draughts of air.

Commercial benefits for business owners

Here are the issues an air temperature difference can present.

Building fabric heat losses will increase without destratification fans

The hotter air in the roof area influences how rapidly the structure loses heat. For example, the working areas temperature may be 20°C. On a chilly day with an outdoor temperature of -2°C, this would result in a temperature differential of 22°C between the working space and the outside. However, the air in the roof space will be roughly 24°C, resulting in a temperature differential of 26°C between the roof space and the outside air.

This is crucial because the temperature gradient influences the rate of heat loss. The greater the temperature differential between the air in the roof space and the outside air, the greater the rate of heat loss through the roof. Reduced heat loss ( and thus saving energy) via the roof covering can be minimised by lowering the temperature of the air in the roof space by using destratification fans to be more energy efficient.

For example, lowering the roof space temperature from 25°C to 21.5°C would result in a 14% reduction in heat loss through the roof surface. In many circumstances, optimising the circulation of warm air by destratification allows for the right temperature in the working space to be maintained using fewer warm air heaters, lowering both capital and operating expenses.

Losses via airflow infiltration

Another consideration is the influence of temperature gradients on the natural rate of ventilation, which occurs when air enters and exits the structure via leakage locations in the building fabric. It is generally known that part of the warm buoyant air ascending into the roof area will escape through high-level leakage spots. This will result in a slight negative pressure, which will attract additional chilly outside air into the structure via lower-level leakage locations. This low-level cold air entering the building lowers the temperature in the building, requiring the heating system to use more energy to achieve the desired temperature. Fabric heat losses and air penetration are especially problematic in older buildings with insufficient thermal insulation and numerous leakage spots.

 

Conclusion

Destratification fans, by mixing the air, eliminate stratified layers of hot air, successfully achieving temperature equilibrium across the entire space, and reduce energy consumption for heating systems.

Air stratification in buildings can be avoided by allowing the inside air to mix and move about. The temperature will be balanced by homogenising the air, or mixing it up and giving it all the same attributes. We call this process “destratification.”

Should you require more product information or get a project sizing on our destratification fans then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us.

Glass Lined Hot Water Storage Tanks

Glass Lined Hot Water Storage Tanks

Glass lined hot water storage tanks or glass-fused-to-steel tanks for storing hot water produced from water heaters such as tankless water heaters hot water system or indirect water heaters such as gas or oil boilers. From 200 to 6,000 Litres in volume by Flexiheat UK

Glass lined hot water storage tanks, also called vitreous enamel lined hot water tanks, are storage tanks or buffers that are normally used for domestic hot water storage(potable water), although the hot water doesn’t have to be of this quality. They are storage tanks manufactured in carbon steel but with glass or vitreous enamel corrosion protection of the metal surfaces in contact with the hot water.

The glass lining provides a robust internal surface for water storage tanks that must endure the wearing effects of high volume, high-temperature hot water and prevents corrosion of the storage tanks.

Glass Lined Storage Tanks

Our glass lined hot water storage tanks can also be used for cold water storage too, as they are designed to withstand temperatures down to 10 degrees C. The hot water temperature limit is 95 degrees C, depending on the model.

How is the vitreous enamelling or glass lining applied?

All interior linings of domestic hot cylinders must be “Food Grade quality” according to EU Regulation 1935/2004. Our vitreous enamelling has food grade certification at 95 °C, ensuring maximum quality at severe operating temperatures.

Using a sophisticated “surface treatment” on the carbon steel surface, combined with an automated enamel coating procedure, results in much more than a robust mechanical adhesion of the lining. A molecular interaction develops between the steel surface and the applied enamel layer during the curing process.

This maximum bonding of the enamel coating to the steel surface, along with the vitreous enamel’s high level of impermeability, makes the product last longer and keeps it from breaking down in ways that can happen with other types of coatings, like the protective coat coming off or blistering.

When to use glass lined storage tanks

These tanks are the most widely used for storing potable or waste water in building services or process equipment applications, but they are also suitable for dosing chemicals, numerous industrial effluents, or reagent materials since they combine the corrosion resistance of glass with the hardness of steel at a very cost-effective price.

Cathodic protection system via sacrificial anodes

A magnesium sacrificial anode in glass-lined tanks assures potable water quality. These sacrificial anodes guarantee that the domestic hot water is safe to drink by drawing contaminants from the nearby water supply. If the magnesium anode rods strike the glass while lying down, it might cause glass shattering or crazing (fine cracks on the surface of the material). It is critical that they be kept and carried upright.

The sacrificial anodes, through an electrochemical process, are designed to attract particles of limestone, iron, and other minerals present in the water and corrode instead of the glass lined tank. In simple terms, it “sacrifices” itself to help the range of glass lined storage tanks last longer.

Most glass lined storage tank manufacturers advise inspecting and evaluating the sacrificial anode’s condition every year and replacing it when it has been depleted by more than 50%. This is particularly important if you have hard water or use a water softener on your domestic hot water.

Storage Tanks Product Range

We have two ranges of glass lined water storage tanks; these are

Our SAC series

These have capacities ranging from 300 to 5,000 litres, with a maximum water temperature of 95 °C.

With a maximum working pressure of 10 bar for the 300 to 1,000 Litre capacity models

As standard, the 1,500 to 5,000 Litre tanks are 6 Bar rated – with the option of 8 bar manufactured units.

All units come with insulation with ErP energy ratings of “B” or “C” depending on size, to prevent heat loss.

Full details on this series of glass lined storage tanks are here –

Download the Flexiheat SAC Glass Lined storage tanks or cylinders for domestic hot water storage brochure

Finished in grey PVC RAL 9006 colour lining or jacket up to 2,000 litres, and white PVC RAL 9001 above this volume.

They are manufactured to the 2014/68/UE Directive, ART. 4.3, without CE marking Standard EN 12897:2016.
These buffers are designed and built in accordance with the requirements of 2009/125/EC.

Labelling in accordance with the requirements of 2017/1369/EU and Delegated Regulation 812/2013 (EU)

Glass lining corrosion protection to DIN 4753 and come with a 5-year warranty.

Our Coral Vito series

This series of glass lined water storage tanks has capacities ranging from 200 litres to 6,000 litres, with a standard pressure of 8 bar (10 bar optional upgrade) and a maximum operating temperature of 90 °C.

These hot water storage models all benefit from an inspection and clean outdoor or manhole which is 146mm for the 200 to 1,500 and a larger 400mm manhole option is available from 800 litres upwards.

 

800 to 1500 litre glass lined water storage tanks with large inspection plate or manhole 400mm -CV- RB range Flexiheat UK

RB models with larger 400mm inspection / clean out manhole

 

Full details are on the following brochure – please see page 10 for 200 to 1,500 Litre tanks , and pages 35 & 36 for the 1,500 to 6,00 Litre tanks

Domestic hot water cylinders and storage vitreous enamelled units from Flexiheat UK

Soft water areas: be aware

Glass-lined storage tanks can succumb to significant corrosive damage quickly under naturally soft water conditions, despite the use of sacrificial anodes.

Purer, soft water has poor electrical conductivity due to a lack of dissolved metal ions; therefore, the electrical flow from the anode to the cathode via the water is decreased. This has a negative influence on the chemical interaction between the sacrificial anode and the storage tank shell, resulting in less protection.

When the sacrificial anode is evaluated in such circumstances, its condition may be exceptionally good, but this is likely to be a significant signal that the anode is failing in its job, implying that the water tank itself is corroding.

An electrically powered anode is a common substitute for the sacrificial magnesium anode rods. A powered anode, which is frequently constructed of titanium, creates a very low current in the water rather than giving up its own electrons and creating an electrolytic current. This should provide a similar level of protection for a glass lined tank while not corroding the anode. However, in soft water conditions, even an electrically powered anode may still be ineffective since the conductivity required by the anode is insufficient.

As a result, in Scotland, west Wales, and the north-west and south-west of England, where the water is very soft, you are almost always going to need a stainless steel hot water storage tank.

Please see more on our range of stainless steel hot water storage tanks

Water heating

These glass lined storage tanks or buffer tanks are often used in conjunction with either tankless water heaters or suitable air source heat pumps, gas, or oil boilers that, via a plate heat exchanger, can provide the domestic hot water and space heating requirements. The glass lined storage tanks provide a buffer volume of hot water to accommodate a variety of peak demands the building or process may encounter.

Hot water system volume

With various capacities of tank sizes available, from a small 200 Litre to 6,000 litres in single tanks (you can also couple the units up in series should you require higher capacities), our range gives us the flexibility to cover all storage capacity requirements you may have.

Glass lined storage tanks

Should you require more product information, check stock, technical support, budget options, prices, or to place an order on our glass lined hot water storage tanks, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us.

120kW Boiler Gas Fired Condensing

120kW Boiler Gas Fired Condensing

 

120kw Boiler gas fired condensing boiler for central heating be it radiators or underfloor heating and domestic hot water Flexiheat UK

 

Our gas fired 120kW boiler for heating commercial systems is available in natural gas or LPG gas (LPG biofuel is compatible as well).

This regular boiler can be used for space heating, central heating (radiators or underfloor heating), and domestic hot water production via accessories such as a plate heat exchanger or an indirect domestic hot water calorifier or cylinder.

They are a high-performance “A “rated efficiency , ErP-compliant condensing boiler and offer enhanced performance that exceeds the Part L building regulations for seasonal energy efficiency requirements. With low NOx Class 6, environmentally friendly emissions

Efficiency features: with a broad range of output modulation ratios of 20:1, automatic part load adjustment offers superb outputs down to 5.75 kw of heat output at 80/60 °C or 6.44 kW heat output at 50/30 °C, which leads to better heat load matching of the system, higher energy efficiencies, lower fuel consumption, and energy saving results.

This energy-efficient commercial boiler also has two stainless steel heat exchangers (2 x 60 kW) in one boiler, which ensures redundancy for your heating system; if one heat exchanger module fails, you still have  50% of your heat duty available. This enhanced performance feature can be vital for commercial customers on a site that can’t be without some heat.

120 kW wall hung gas condensing boilers

With the option of installing the boiler as a wall-to-wall solution or arranged on a suitable free-standing frame kit for floor-mounted installation, depending on site requirements.

120kw output gas fired commercial condensing boiler in natural gas or propane gas fuel with high thermal efficiencies for energy savings.

Our 120kW gas fired condensing boiler on a free standing frame kit, with low loss header and plate heat exchanger for Domestic Hot Water production.

We can provide a solution for every commercial heating specification or commercial system, as we can cascade these high performance gas boilers up to 960 kW with automatic part load adjustment with an intelligent fault system that will monitor and report any faults on these commercial specification boilers.

Commercial gas boilers high efficiency condensing boilers for heating either floor standing boilers or wall hung boilers for central heating in commercial applications - Flexiheat UK

Floor standing or wall hung gas commercial boilers from Flexiheat UK

 

120kW commercial wall hung gas boilers

As each boiler (heat exchanger) has its own flue non-return valve, you can service either boiler heat exchanger module without shutting the space heating system down.

120kW gas boiler with two heat exchangers for energy efficient low carbon central heating and domestic hot water via an indirect hot water cylinder or heat exchanger- R1K120 from Flexiheat UK

Two heat exchangers – redundancy for the heating system – a wall to wall solution

 

Our energy-efficient condensing gas 120 kw boilers are fitted with fully modulating low NOx burners (Class 6 combustion levels) for lower environmental impact.

R1K120 gas condensing boiler output and energy efficiency figures—Part L building regulations

The latest changes to Part L of the Building Regulations, which went into effect on June 15, 2023, say that all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously, 75°C plus boiler flow temperature was allowed) and preferably lower if possible to get the most condensing heat transfer from condensing boilers, which results in high energy efficiencies.

Thus, our gas boiler will produce up to 125.67 kW heat output when the heating system flow and return temperatures are 50/30 °C.

The unit will also provide 114.64 kW at 80/60 °C heat output if you have a process heating application that is not covered in the Part “L” building regulations.

Full data is shown in the following:

 

This is detailed in our full manual, which can be downloaded here.

Manual for R1K120 Gas Condensing Boilers, Internal Version, Flexiheat UK

Should you require a larger output gas boiler (we do up to 240 kW in a single boiler and up to 980 kW in a cascade system), then we do a full range of gas condensing boilers for commercial use, which are listed here.

Gas commercial condensing boiler range

Condensing boiler specifications

  • “A” ErP efficiency rating wall-hung boiler designed for commercial use or a very large home domestic central heating system and DHW for multiple bathrooms via a hot water cylinder or plate heat exchanger

  • Low Class 6 NOx flue gas emissions make these more environmentally friendly as low carbon solutions today.

  • Straightforward and easy install: all plumbing connections are at the bottom of the unit, saving installation costs.

  • Energy efficient condensing boilers up to 105.8 %  at 50/30°C flow and return hot water temperature.

  • Stainless steel heat exchanger with 28mm diameter water ways that ensure the boiler benefits from very low pressure drops, guarantees lower risks of clogging (more resistance to fouling up), greater thermal efficiency, and greater ease of cleaning.

  • Can be arranged inline for larger output requirements to cover any commercial specification, but not back to back at present.

  • These 120-kW gas-fired boilers have the identical outstanding efficiency and performance characteristics as their smaller domestic counterparts.

  • Intelligent fault system: it will monitor system pressure, i.e., if the central heating system installation pressure is too low, etc.

System pressure

  • Maximum heating operating system pressure = 3 bar
  • Maximum heating operating system pressure = 0.3 bar

Controls

  • An “Opentherm” thermostat controller, such as a “Hive” or “Nest” type, can control the boiler’s operation and temperature either locally or on the go using your phone, tablet, or computer. You can also use a basic thermostat; the choice is yours.
  • BMS compatible with our 0–10 volt free contact kit

Boiler Fuel type

This 120kw high performance boiler can be powered by natural gas or LPG applications

Dimensions of this regular boiler: 120 kW Output for central heating and domestic hot water heating

This boiler has the following compact dimensions: 670 mm wide, 485 mm deep, and 642 mm high.

Dimensions of our 120kw condensing boiler gas fired in natural gas or LPG- ErP "A" rated for central heating (radiators or underfloor heating) and domestic hot water via a calorifier from Flexiheat UK

 

Connection details at the bottom of the unit: flow and return connections, gas connection, and condensate drain.

Connection details of our 120kW condensing gas fired boiler Flexiheat UK

Free standing frame installation detail

Floor standing mounting kit

Gas fired 120kw condensing boiler on a free standing frame with low loss header Flexiheat UK

Boiler on our optional free-standing floor frame kit with low loss heating system header

120kW gas system boiler

Are these an 120kW gas system boiler? Yes, in that they have a pump (two pumps actually, i.e., one for each heat exchanger module), but at this size of system boiler, we can’t fit an heating expansion vessel within the boiler casing, so one needs to be fitted to the plumbing pipework external to the boiler to make the unit a full system boiler.

Flue options

Each heat exchanger module features its own flue exhaust connection. You can either individually flue each unit with an 80mm or 100mm flue up to 25 or 30 metres, respectively, either vertically or horizontally in range. However, if you use a split flue system, i.e., an 80mm flue diameter for the combustion air and 80mm for products of combustion, you can go up to 40 metres vertically or horizontally in range.

The last accessories option is a 100mm common flue header for the boiler.

R1K120 gas fired boiler with common flue header

Common flue header kit

Gas-fired 120 kW boilers

Should you require more product information, check stock, technical support, budget options, prices, or to order on our 120kw boiler in natural gas or LPG, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us.

Boiler flow temperature for central heating regulations Part L June 2023

Boiler flow temperature

Boiler flow temperature ? hot water heating systems in newly constructed homes or commercial buildings must now be designed to operate at a maximum flow temperature of 55°C as a result of changes to the Building Regulations.

The low flow temperature information

The latest revisions to Part L of the Building Regulations seek to reduce emissions by 31% for both new build houses and home renovations and additions, which is a crucial milestone in the UK’s journey towards net zero.

Since the year-long transition period finished on June 15, 2023 (it did not apply to work subject to a building notice, full plans application, or initial notice submitted before that date, provided the work for each building is started before June 15, 2023), the original measures that went into effect on the 15th June 2022 apply. Heating installers must be aware of the new regulations that now apply without fail.

These modifications served as a significant first step towards the Future Homes Standard, which targets reducing emissions from all new construction by 75–80% by 2025.

Part L of the building regulations

For both new builds and home extensions or renovations, the stipulated modifications to Part L define a 31% decrease in carbon emissions compared to prior requirements. Part L, which places a strong emphasis on low-carbon heating systems, also emphasises a fabric-first strategy. Changes include an improvement in fabric airtightness and insulation standards, better U-values, and thicker insulation in homes.

For buildings, Part L of the building regulations is divided as follows:

New-build homes and buildings: Part L1A Regulations

This document outlines the energy efficiency requirements for new construction. Approved Document, Part L1A

It describes how all new houses will now be valued using the SAP10 Standard Assessment Procedure (SAP) formula. This approach, which was previously derived using SAP 2012, has been updated to SAP 10. Greater insulation needs and a new target primary energy rate, expressed in kWhPE/m2 per year, are defined as a result of the SAP calculation being performed at the design stage. As a result, achieving SAP compliance will rely heavily on good water heating system design.

Additionally, all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously 75°C plus boiler flow temperature were allowed), as required by Part L1A. This will make it much simpler for houses to be retrofitted with air or ground source heat pumps in the future, when they replace a condensing boiler, be they condensing gas boilers or an oil condensing boiler as the radiators and pipework will be sized correctly for the central heating to work at these temperatures and produce maximum efficiency.

Existing properties and buildings, Part L1B

 Part L1B, an approved document, discusses energy and fuel conservation in existing homes.

Even though Part L1B acknowledges that it is not always practicable to achieve new build standards.

Quote: “Where it is not feasible to install a space heating system that can operate at this flow temperature of 55 °C or lower (e.g., where there is insufficient space for larger radiators, or the existing distribution system is provided with higher temperature heat from a low carbon district heat network), the space heating system should be designed to the lowest design flow temperature possible that will still meet the heating needs of the dwelling.

Source: HM Government – Part L 2021 edition incorporating 2023 amendments, for use in England, Page 36

Part L1B specifies that wet central heating systems that are new or being replaced shall, whenever practicable, be sized at a maximum boiler water flow temperature of 55°C.

Importantly, the regulations stipulate that if a thermal element ( wall, roof, or floor) of the home is being renovated or replaced, the work must be done to Part L1A requirements.

Commercial/non-domestic buildings are covered in Part L2a

Again, same regulations for the maximum flow temperature of 55°C or lower, but this document refers to commercial and industrial heating applications that are not domestic dwellings.

Referring document / legislation is here –

Part L2a requirements for energy efficiency compliance for commercial/non-domestic buildings

Low temperature heating advantages

Lower heating flow temperatures are now mandatory in the design of an increasing number of household heating systems, whether they utilise a gas boiler or a heat pump. Installing a condensing gas boiler on a low temperature system will result in cost savings for homeowners and reduce energy bills.

The boiler will always operate in condensing mode while the boiler temperature is set to a flow temperature of 55°C or lower. This makes the boiler and heating system far more effective and guarantees that they are always capturing the latent heat from condensation. As a result, the boiler will run as close to its condensing efficiency as possible, which will result in cheaper energy costs for homeowners.

All radiators and piping installed as part of a new or replacement system must be sized for a maximum flow temperature of 55°C, according to Part L. As a result, it could be necessary to use larger pipework and install radiators of the correct size to adequately heat the space.

When done appropriately, this work can significantly contribute to future-proofing a building so that low carbon technologies like heat pumps, which also employ low flow temperatures, can be installed in the future.

“A gas boiler will function as closely to its condensing efficiency at the boiler’s flow temperature of 55°C (55°C is the dew point temperature at which the condensing mode starts to work in gas boilers, as the flue gases condense and they can recover the latent heat), which will reduce a homeowner’s energy heating bills.”

In short, a lower boiler water flow temperature means reduced heating bills for your central heating system.

How to design and install a low temperature heating system and what to think about

Installers must take into account the wider system as well as the overall design of the building, including heat loss calculations, because the design of a low heating flow temperature system differs from that of a traditional higher boiler’s flow temperature system. By doing this, they can ensure that any future switch from a gas boiler to a heat pump can be made smoothly.

Heating flow temperature

The most important component of the regulations for the majority of installers will be Part L1(b), which focuses on the conservation of fuel and electricity in existing residential dwellings. Part L1(a) addresses the energy efficiency of newly constructed homes (learn more about what Part L means for newly constructed homes here).

It is crucial to note that it specifies that new or replacement wet central heating systems should be built to operate at a maximum flow temperature of 55°C rather than the 75°C typical of conventional heating systems to ensure boiler efficiency in modern boilers that are all now condensing boilers.

Heating system

1. A minimum of insulation All pipes linked to the hot-water storage are subject to thicknesses. Insulation must be at least 5mm thick for pipes having an internal diameter of 10mm, 10mm for pipes with an internal diameter of 22mm, and 15mm for pipes with an internal diameter of 28mm.

2. Thermostatic radiator valves are needed for every installation, with the exception of heat pump installations, which need volume for defrost.

3. For brand-new and completely replaced systems, the maximum flow temperature is 55°C.

4. Insulation is required for all principal hot water pipes used for home hot water.

5. When passing through voids, secondary central heating pipes must be insulated.

6. Multi-zoning is necessary if the total floor space is 150 m2 or greater.

7. When passing through voids, primary central heating pipes must be insulated.

8. In accordance with BS 7593, all primary hot-water and central heating circuits should be properly cleaned, flushed out, and dosed with inhibitor on each installation.

What does this mean for condensing combi boilers?

A combi boiler produces hot water on demand and has no hot water cylinder attached to the boiler, unlike a system boiler. The boiler flow temperature setting on a combi boiler for the heating side of the condensing combi boiler can be set to a thermostat temperature of 55C, and you can achieve the standard hot water temperature required of 40C for the domestic hot water side of the combi boiler with ease with our combi boiler range.

These are listed here

Our fully modulating 24kW combi boiler in natural gas or LPG  

our 35kW fully modulating combi boiler in natural gas or LPG 

or our largest combi boiler 50kw combination boiler in natural or LPG gas 

Hot water cylinders

Lower flow temperatures can cause issues for a hot water cylinder, as domestic hot water needs to be stored at 60 °C to avoid legionella. This means that the boiler flow temperature to the heat exchanger coil in an indirect hot water cylinder must be higher than the hot water temperatures within the cylinder for the heat to transfer to the domestic hot water. Newer boiler models these days have a system that will ramp up the boiler’s flow hot water temperature temporarily to achieve the correct temperature and heat the hot water cylinder.

Alternatively, immersion heaters can be used to top up the heat required for the hot water cylinder

Conclusion

Changing your boiler temperature, or now, as required, designing a lower flow temperature system, is now mandatory. Whether you’re using a combi boiler or system boilers, the boiler temperature settings must be a maximum of 55 °C and the system designed accordingly, as they have to be future-proof for low carbon heating solutions such as heat pumps.

With a boiler flow temperature of 55 °C and a return temperature that is even lower, this allows the boiler to recover the latent heat for the condensing process, lowering the heating bill / gas bills, as recommended by the energy saving trust.

70kW Boiler Gas Fired Condensing

70kW boiler gas fired condensing

70kw Boiler gas fired condensing boiler for central heating be it radiators or underfloor heating and domestic hot water in a environmentally friendly way from Flexiheat UK

 

Our gas fired 70kW boiler is available in natural gas or for LPG gas fuel (LPG biofuel compatible to). They are a high-performance “A “rated efficiency , “ErP” compliant condensing boiler and offer enhanced performance that exceeds the Part L building regulations for seasonal energy efficiency requirements. With low NOx Class 6 environmentally friendly emissions.

This regular boiler can be used for space heating, central heating (radiators or underfloor heating), and domestic hot water production via a plate heat exchanger or indirect domestic hot water calorifier or cylinder.

Efficiency features: with a modulation ratio of 20:1, the automatic part load adjustment offers superb outputs down to 3.5 kw of heat output, which leads to better heat load matching of the system, lower fuel consumption, and you’ll save on energy costs.

This energy efficient commercial boiler also has two stainless steel heat exchangers in one boiler, which ensures redundancy for your heating system; if one heat exchanger module fails, you still have up to 50% of your heat duty available. This feature can be vital for commercial customers on a site that can’t be without some heat.

The unit comes with a 2-year warranty for parts , and the heat exchanger has a 5-year warranty if, as required by the building regulations, a dirt and air separator is fitted to protect the system, and the product is serviced annually.

70 kW wall-hung gas condensing boilers

With the option of installing the boiler as a wall-to-wall solution or arranged on a suitable free-standing frame kit for floor-mounted installation, depending on site requirements.

Gas condensing boiler, which is a regular boiler on a free-standing frame kit the R1K range 50kw to 120kw outputs from Flexiheat UK

The 70kW gas fired condensing boiler mounted on a free-standing frame kit with low loss header and plate heat exchanger of domestic hot water production.

We can provide a solution for every commercial specification, as we can cascade these high performance gas boilers up to 960 kW with automatic part load adjustment if so required.

commercial gas boilers; commercial lpg boiler; wall hung gas commercial boilers; commercial boilers in cascade which are a regular boiler

70kW commercial wall hung boilers

As each boiler (heat exchanger) has its own flue non-return valve, you can service either boiler heat exchanger module without shutting the space heating system down.

Our energy-efficient gas 70kw boilers are fitted with fully modulating low NOx burners (Class 6 combustion levels) for lower environmental impact.

70 kW gas boiler with two heat exchangers for energy efficient low carbon central heating and domestic hot water via an indirect hot water cylinder the R1K75 from Flexiheat UK

Two heat exchangers for redundancy in one boiler casing with an output of 70 kW

R1K75 gas condensing boiler output and energy efficiency figures—Part L building regulations

The latest changes to Part L of the Building Regulations, which went into effect on June 15, 2023, say that all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously, 75°C plus boiler flow temperature was allowed), and preferably lower if possible to get the most condensing effect from boilers.

Thus, our gas boiler will produce up to 79.35 kW when the heating system flow and return temperatures are 50/30 °C.

The unit will also provide 72.83 kW at 80/60 °C if you have a process heating application that is not covered in the Part “L” building regulations.

Full data is shown in the following:

R1K75 gas condensing boiler output and energy efficiency figures Flexiheat UK

Output and energy efficiency figures for our R1K75

 

This is detailed in our full manual, which can be downloaded here.

Manual for R1K 75 Gas Condensing Boilers – Internal version Flexiheat UK

Should you require a larger output gas boiler (we do up to 240 kW in a single boiler and up to 980 kW in a cascade system, then we do a full range of gas condensing boilers, which are listed here.

Commercial gas condensing boiler range

Specifications

  • “A” ErP efficiency rating wall-hung boiler designed for commercial use or a very large home domestic central heating systems and DHW for multiple bathrooms via a hot water cylinder.
  • Low Class 6 NOx flue gas emissions making these more environmentally friendly.
  • Straightforward and easy install: all plumbing connections are at the bottom of the unit saving installation costs.
  • Energy efficient condensing boilers up to 105.8 % at 100% heat input at 50/30°C
  • Stainless steel heat exchanger with 28mm diameter water ways that ensure the boiler benefits from very low pressure drops, guarantees lower risks of clogging (more resistance to fouling up), greater thermal efficiency, and greater ease of cleaning.
  • Intelligent fault system: if the boiler has a fault, it will tell you exactly what has gone wrong, i.e., if the heating system installation pressure is too low, etc.
  • Maximum heating operating system pressure = 3 bar
  • Maximum heating operating system pressure = 0.3 bar
  • An “Opentherm” thermostat controller, such as a “Hive” or “Nest” type, can control the boiler’s operation and temperature either locally or on the go using your phone, tablet, or computer. You can also use a basic thermostat; the choice is yours.
  • BMS compatible with our 0–10 volt free contact kit

 

Dimensions of this regular boiler: 70 kW Output for central heating and domestic hot water heating

This boiler has the following compact dimensions: 670 mm wide, 495 mm deep, and 642 mm high.

Dimensions of our 70kw condensing boiler gas fired in natural gas or LPG- ErP "A" rated for central heating (radiators or underfloor heating) and domestic hot water via a calorifier from Flexiheat UK

A small compact energy efficient gas condensing boiler 70 kW with ErP “A” rated for central heating (radiators or underfloor heating) and domestic hot water via a calorifier.

Connection details at the bottom of the unit: flow and return connections, gas connection, and condensate drain.

Connection details of the 70kW condensing gas fired boiler Flexiheat UK

Free standing frame installation detail

Floor standing mounting kit

Gas fired 70kw output condensing boiler on a free standing floor frame kit with low loss header Flexiheat

Boiler on our floor free standing frame kit with low loss heating system header option

 

70kW gas system boiler

Are these an 70kW gas system boiler? Yes, in that they have a pump (two pumps actually, i.e., one for each heat exchanger module), but at this size of system boiler, we can’t fit an expansion vessel within the boiler casing, so one needs to be fitted to the plumbing pipework external to the boiler to make the unit a full system boiler.

Flue options

Each heat exchanger module features its own flue exhaust connection. You can either individually flue each unit with a co-axial flue (80mm/125mm) should you wish to go room-sealed up to 10 metres vertically or horizontally in range. However, if you use a split flue system, you can go up to 40 metres vertically or horizontally in range.

The last option is a common flue header for the boiler.

R1K75 gas boiler with common flue header option

Common flue pipe header option

Gas fired 70 kW boilers

Should you require more product information, check stock, technical support, prices, or to order on our high performance 70kw boiler in natural gas or LPG, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us. Follow our business on Facebook or Twitter if you’re interested in being informed of our latest recommend manufacturer product range items deal.

80kW Boiler Gas Fired Condensing

80kw Boiler – gas fired condensing

80kw Boiler gas fired condensing boiler for central heating and domestic hot water Flexiheat UK

 

Our gas fired 80kW boiler is available in natural gas or for LPG applications. They are a high performance “A” rated ErP condensing boiler, and offer enhanced performance that exceeds the Part L building regulations for seasonal energy efficiency requirements.

This unit can be used for space heating, central heating, and domestic hot water production via a plate heat exchanger or indirect hot water cylinder or water heaters

Efficiency features: with a modulation ratio of 20:1, the automatic part load adjustment offers superb outputs down to 3.5 kw of heating output, which leads to better heat load matching of the system and lower fuel consumption and energy bills.

This energy efficient commercial boiler also has two stainless steel heat exchangers in one boiler as such, which ensures redundancy for your heating system; if one heat exchanger module fails, you still have up to 50% of your duty available. This feature can be vital in a commercial specification for a building that can’t be without some heat.

Wall Hung Gas Commercial Boiler

With the option of installing the boiler as a wall to wall solution or arranged inline on a free standing frame kit to offer enhanced performance.

Gas condensing boiler on a free-standing frame kit the R1K range 50kw to 120kw outputs from Flexiheat UK

The 80kW gas fired condensing boiler mounted on a free-standing frame kit with low loss header and plate heat exchanger of domestic hot water production.

 

We can provide a solution for every commercial specification, as we can cascade these high performance gas boilers up to 960 kW with automatic part load adjustment if so required.

commercial boilers wall hung for heating Flexiheat UK

For more details on this – please click here- cascading our commercial gas boilers 

80kW commercial wall-hung boilers

As each boiler (heat exchanger) has its own flue non-return valve, you can service either boiler heat exchanger module without shutting the space heating system down.

Our energy efficient gas boilers are fitted with fully modulating low NOx burners (Class 6 combustion levels) and fan for low carbon solutions.

 

80kW boiler with two heat exchangers for energy efficient low carbon central heating and domestic hot water via an indirect hot wa80kW boiler with two heat exchangers for energy efficient low carbon central heating which can be radiators or underfloor heating and domestic hot water via an indirect hot water cylinder the R1K75 from Flexiheat UK

R1K75 gas condensing boiler output and energy efficiency figures – Part L building regulations

The latest revisions to Part L of the Building Regulations that came into force on June 15, 2023, mean that all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously 75°C plus boiler flow temperature were allowed), as required by Part L1A, and preferably lower if possible to achieve the maximum condensing effect of boilers.

Thus, our gas boiler will produce 79.35 kW ( close enough to 80 kW for us) when the heating system flow and return temperatures are 50/30 °C. However, should you require more kW output, please look at the next size boiler up our 100kW boiler which again is available in natural gas or for lpg applications and offers superb outputs up to 106.8 kW.

The unit will also provide 72.83 kW at 80/60 °C if you have a process heating application that is not covered in the Part “L” building regulations.

Full Data is shown in the following –

R1K75 gas condensing boiler output and energy efficiency figures Flexiheat UK

Output and energy efficiency figures for our R1K75

This is detailed in our full manual which can be downloaded here –

Manual for R1K 75 Gas condensing boiler – Internal version Flexiheat UK

Should you require a larger output gas boiler (we do up to 240 kW in a single boiler), then we do a full range, which is listed here.

Commercial gas condensing boilers 

Specifications

  • “A” rated wall hung boiler – for commercial use or very large home heating applications.

  • Energy efficient condensing boilers up to 105.8 % at 100% heat input at 50/ 30°C

  • Stainless steel heat exchanger with 28mm diameter water ways that ensure the boiler from very low pressure drops, guarantees lower risks of clogging (more resistance to fouling up), greater thermal efficiency, and greater ease of cleaning.

  • Intelligent fault system: if the boiler has a fault, it will tell you exactly what has gone wrong, i.e., if the heating system pressure is too low, etc.

  • Pressure sensor to monitor system pressure as part of the intelligent fault system

  • Maximum heating operating system pressure = 3 Bar

  • Maximum heating operating system pressure = 0.3 Bar

  • Can be controlled by an “Opentherm” controller, such as a “Hive” or “Nest” type, which means you can control the boiler on the go from your mobile phone, tablet, or PC, just like our full range of smaller domestic counterparts that we supply.

  • BMS compatible with our 0-10 Volt free contact kit

 

Dimensions of this commercial boiler: 80 kW gas-fired

This commercial boiler has the following compact dimensions:

Dimensions of our 80kw condensing boiler gas fired in natural gas or LPG- ErP "A" rated for central heating (radiators or underfloor heating) and domestic hot water via an indirect domestic hot water cylinder from Flexiheat UK

A small compact energy efficient gas condensing boiler 80 kW with ErP “A” rated for central heating (radiators or underfloor heating) and domestic hot water via an indirect domestic hot water cylinder.

 

Connection details at the bottom of the unit: flow and return connections, gas connection, and condensate drain.

Connection details of the 80 kW gas boiler Flexiheat UK

 

Free standing boiler frame detail

Gas fired 80kw condensing boiler on a free standing frame with low loss header Flexiheat UK

The gas condensing boiler on a free standing frame kit with low loss header.

80kW gas system boiler

Are these an 80kW gas system boiler? Yes, in that they have a pump (two actually, i.e., one for each heat exchanger module), but at this size of system boiler, we can’t fit an expansion vessel within the boiler casing, so one needs to be fitted to the pipework external to the boiler to make the unit a full system boiler.

Flue options

Each heat exchanger module has its own flue exit. You can either individually flue each unit with a co-axial flue (80mm/125mm) should you wish to go room sealed up to 10 metres vertically or horizontally. However, if you use a split flue system, you can go up to 40 metres vertically or horizontally.

The last option is a common flue header for the boiler.

R1K75 gas boiler with common flue header option

Common flue pipe header option

 

Gas-fired 80 kW Boiler

Should you require more product information, check stock, technical support, or prices on our high performance 80kw boiler in natural gas or LPG ,then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us.

Buffer tank with coil or twin coils

Buffer tank with coil or twin coils

A buffer tank with coil or coils is used to hydraulically separate a heat source or sources, in the event of a twin coil buffer tank, from the heating system’s hot water. This can be required for mechanical engineering reasons such as flow rate or temperature difference between the heating system and the heating source , which is often the case with heat pump heating systems, be they air source heat pumps or geothermal heating systems.

With a full range of buffer tanks from 260 litres in hot water storage volume all the way up to 5,000 litres of storage capacity, we have the volumes to satisfy any application or performance requirements for your inertia tank.

We do two ranges which will detail below

Why use a buffer with a coil ?

The coil acts as a heat exchanger, separating the hot water generated from a heat pump, boiler, or solar thermal fluid in the event of a solar thermal system from the hot heating water in the thermal storage tanks.

This can ensure that there are no problems with flow rates between the heated water from the heat source and the heating system, and also temperature differences, i.e., some solar system fluids can get up to 200 °C, whereas the storage tank temperature ratings are either 95 °C or 110 °C maximum. Thus, the use of a heat exchanger coil within the buffer tank is required.

The coils used are not a stainless steel coil , like those used in an indirect water heater that produces domestic hot water. We are not producing domestic hot water in a buffer tank with an intermediate heating coil to produce hot water for the heating system. The coils are made of steel, just like the thermal storage tanks.

Which means these buffer tanks must be used on a sealed heating system only, and the heating water must be treated with a corrosion inhibitor.

Domestic hot water production

If you want a Buffer tank with a stainless steel coil to produce domestic hot water, then these are called Thermal store hot water cylinders or Thermal store cylinders – and we go into more detail on this range here: https://www.flexiheatuk.com/product/thermal-store-cylinders/ as these are our units for instantaneous domestic hot water heating or production via a stainless steel coil within the thermal storage tank and are available in volumes from 500 litres of storage to 2000 litres in range or size.

Single heat exchanger models

The first range is the “G” range. These are rated

Maximum working pressure: Coil – 25 Bar – Tank 6 bar

Maximum working temperature: Coil – 200 ºC – Tank 110 ºC

Single coil buffer tanks the G-IF or G-IFS range 260 litres to 1500 litres that are thermal stores to accommodate peak loads for the heating system, using an intermediate coil to hydraulically separate the heat source from the heating system water in a hot water cylinder from Flexiheat UK

The storage tank also has an immersion heater port, should you wish to install an immersion heater as a back up or top up heat source.

 

Technical data: The “G -IS” buffer tank range has larger tapping ports than the “G – IFS” buffer tank range, which has the standard 40mm (1-1/2″) See “EH” detail on the following:

G range of buffer tanks with single coil or heat exchanger detailing the hot water tapping detail on the buffer tank or thermal stores and heat exchanger detail Flexiheat UK

G-IS and G-IFS Buffer tank with a single coil / heat exchanger technical detail

 

Larger Size Storage Tank

Thermal storage tanks with hot water storage volumes ranging from 1,500 to 5,000 litres with a single coil.

These buffer tanks are available with an inspection and clean out manhole that is 400mm in diameter and are designated the “ISB” version.

Or as the standard unit without which is designated the “IS” version.

Buffer tanks with a single coil from 1500 litres to 5000 Litres in volume MV range Flexiheat UK

 

Technical detail

MV1500 to 5000 Litre buffer tanks with a single coil technical detail from Flexiheat UK

The full detail on the above tanks can be found in the following brochure – pages 12 & 13

Buffer Tanks Brochure Flexiheat UK

 

Solar thermal heating systems

Some fluids in the solar system can be heated to 200 °C. If this is the case, you need to use our “G” or “MV” range. However, if your water or fluid temperature is less than 110 °C, then we have another buffer tank product with a single coil, and these are detailed here:

Twin coil buffer tanks

Twin coil or two heat exchanger buffer tanks are suitable for applications with two energy heating systems feeding the thermal storage tanks. For example, one coil or heat exchanger can be fed by a thermal solar system, which is usually the lower coil in the buffer tank. The second coil or heat exchanger, which is located in the upper part of the buffer tank, can be fed by heat generated from either a traditional gas or oil boiler or heat pump heating systems, which can be either ground source heat pumps or air source heat pumps.

PPS2 Twin coil buffer tanks for sealed heating systems Flexiheat UK

Our Twin coil buffer tanks from 300 to 2,000 Litres in volume

 

These units are available from 300 to 2,000 litres in demand capacity.

The twin coil range has a heat exchanger maximum hot water temperature rating of 110 °C and 12 Bar pressure .

The buffer tank’s maximum temperature rating is 95 °C, and the pressure rating varies with the volume; please see the brochure for full details.

Flexiheat brochure for PPS2 Buffer tank with twin coils for sealed heating systems

Buffer tank with a coil or coils

Should you require more product information, availability, technical support, or prices on our complete range of buffer tanks with coil or coils then please don’t hesitate to get in touch. Contact our sales service team on 01202 822221 or use our email contact form via the contact tab above to message us.

1000 Litre Buffer Vessel or Tank

1000 Litre buffer vessel or tank

1000 Litre buffer vessel or tank from Flexiheat UK

Our 1000 litre buffer vessel or 1000 litre buffer tank is a hot water buffer tank or vessel that is typically installed to increase the volume of hot water in the heating system to store heated water for later use.They are also referred to by some as a 1000 litre thermal store.

They work best with heat pumps because they store the excess energy the heat pump produces during times of low demand and release it during times of high demand.

Our buffer tanks or accumulator tanks are as such a thermal store for hot water systems and this energy is stored for later use, resulting in fewer but longer heating cycles for heat pump systems, wood pellet boilers, gasification boilers or a biomass heating system.

This is 1000 litre buffer tank is just one of our large range of buffer tanks and vessels . Our full large range of other size buffer tanks is detailed on this webpage – Buffer tanks

Heat pump systems

This buffer tank is ideal for use with heat pumps, allow approximately 25 litres of volume per kW of heat pump output if the manufacturer hasn’t specified a buffer tank / accumulator tank volume.

Wood pellet boilers

For wood pellet boilers sizing – allow a minimum of 10 litres of buffer tank volume for every 1 kW of boiler output.

Gasification boilers

For gasification boilers or log fired biomass boilers – allow a minimum of 50 litres of  buffer tank volume for every 1 kW of boiler output.

1000 Litre Vessel – Buffer tank product description

This 1000 litre buffer vessel / accumulator tank has a working pressure of 8 Bar and maximum temperature of 95C for sealed heating systems and are not to be used on chilled water.

This 1,000L buffer vessel, or buffer tank is manufactured from mild steel or carbon steel. Please note corrosion inhibitors must be used on the heating water system to protect the product i.e. the buffer tank from corrosion .

Technical specifications of our buffer tanks / accumulator tanks are as follows –

1000 Litre Buffer vessel port details for the buffer plus range from Flexiheat UK to store heating hot water from various energy sources for peak demand use in hot water systems.

1000 Litre Buffer vessel / Accumulator tank / Cylinder thermal store for heating water

 

Buffer tank storage capacity – 1000 Litres nominal – 840 Litres Actual

Buffer tank height – 2,065 mm

Buffer tank pivot height – 2,270 mm

Diameter with Insulation: 940 mm

Diameter without Insulation: 790 mm

Pressure rating – 8 Bar maximum working pressure

This 1000 litre buffer vessel has a removeable insulation system, that allows you to get the thermal store through a standard 800mm wide door.

Removeable insulation system on our 1000 Litre buffer vessel Flexiheat UK

Product insulation is polyurethane – 75 mm insulation

Rigid expanded polyurethane insulation with 95% closed cells, CFC and HCFC free, fire resistance to class B2 according to DIN 4102-1.

The insulation is removable – which can help to get the buffer tank through doorways or access points

Great quality product at a great price and available from stock or on a short delivery

Buffer tank weight – 160 Kg when empty – 1,000 Kg’s when full with hot water

Eight tappings – 1 1/2″ female BSP, which enables the installation of immersion heaters as back up or top up heating

Four sensor or thermometer tappings – 1/2″ female BSP

1 x Air vent eliminator or safety valve tapping – 1 1/2″ female BSP

For full dimensions please see the following brochure –

Download the Buffer Plus range of buffer tanks and vessels brochure from Flexiheat UK

Contact Us

If you require further information, product availability, check stock levels, delivery times or prices on our 1000 Litre buffer vessel / accumulator tanks for sealed heating systems or other sizes from our large range of accumulator tanks, then please contact our sales service team on 01202 822221 or use our email contact form via the contact tab above to message us.

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Stainless steel hot water cylinders

Stainless steel hot water cylinders

stainless steel hot water cylinders unvented or vented in duplex stainless-steel Flexiheat UK

Stainless steel hot water cylinders have rapidly grown in popularity in the UK, as in comparison to conventional enamelled steel hot water cylinders of the same capacity, stainless steel hot water systems are lighter and simpler to install. Long-term maintenance and servicing costs are decreased because a sacrificial anode is not necessary for protection.

With regards to a copper cylinder, they are similar in weight and dimensions, but stainless steel domestic hot water storage tanks can be used at a higher pressure.

Austenitic stainless steel or duplex stainless-steel is a suitable material for a hot water cylinder since it doesn’t need cathodic protection to prevent corrosion on its surface.

Stainless steel pressurised hot water cylinders

There is no feed tank or cold water tank in an unvented system as they use mains water pressure. As unvented cylinders run at mains pressure, sealed hot water cylinders provide substantially superior flow rates, making for more pleasurable baths and showers as they are supplied directly from the cold water mains unlike a vented hot water cylinder.

They can be indirect cylinders, whereby the stainless steel hot water cylinders have an external heating source such as a boiler supplying the heat exchanger, which heats up the unit.

We go into more depth on our indirect unvented cylinders in duplex stainless-steel from 80 to 500 litres on this dedicated webpage –
https://www.flexiheatuk.com/product/indirect-unvented-cylinders/

indirect unvented cylinders stainless steel Flexiheat UK

Direct hot water cylinder range in Stainless-Steel

Or they can be a direct cylinder, whereby the cylinder is heated directly by an immersion element or a series of immersion heaters fitted into the cylinder. An immersion heater requires an electric supply to power this range or type of cylinder. Direct stainless steel hot water cylinders are often used where a gas supply isn’t available.

We go into more depth on this range on their dedicated webpage –  direct unvented cylinders in duplex stainless-steel from 80 to 500 litres 

Vented hot water cylinder in stainless steel

In UK homes, vented hot water cylinders are still a typical form of hot water system. Vented cylinders operate by drawing cold water from a header tank, which is normally found in the loft, and then utilising gravity to circulate hot water throughout the house.

A vent line connects the vented hot water cylinder to the cold water in the header tank to maintain the hot water pressure’s stability with expansion.

Because the hot water pressure is normally determined by the height of the water tank above the tap or shower feed, the pressure of the hot water can be very poor when using a vented hot water cylinder.

Vented cylinders, however, are easier to install and maintain.

The downside of vented cylinders is that they require more space, with tanks in loft space , and that the water pressure is often low, resulting in poor hot water flow rates, especially upstairs in a property.

To boost the pressure of the hot water delivered under gravity to the showers and taps in homes with a vented cylinder, many individuals install electric pumps to help boost the pressure.

Normally, properties or homes with a system boiler supplying the central heating system require an indirect unvented cylinder, whereas properties with standard or regular boilers require an indirect vented cylinder.

Our vented cylinders are the same as our unvented range, just supplied without the unvented G3 Kit.

Which is better, copper or stainless steel hot water cylinders ?

Copper is one of the most effective heat conductors and allows for greater heat transmission within hot water cylinders, resulting in quicker hot water delivery. Copper is less competitive when compared to stainless steel when it comes to long-term cost savings since stainless steel has a considerably stronger resistance to all types of corrosion than copper, including corrosion in crevices and stress. This makes stainless steel highly durable and promises a longer lifespan when compared to a copper cylinder.

Stainless Steel

However, due to stainless steel’s capacity to sustain extremely high pressure, unvented hot water cylinders are now commonplace. Due to their ability to deliver hot water under mains pressure, unvented hot water cylinders have become increasingly popular.

Since stainless steel is the ideal material for a pressurised system, it has taken over as the standard material to cover all your needs when compared to a copper cylinder. We can supply a pre-plumbed stainless steel hot water cylinder that are part of our range.

pre plumbed unvented hot water cylinders from Fexiheat UK;

Contact us

Should you require any more information or want to check stock or prices on the best stainless steel hot water cylinders on the UK market with a warranty of 25 years (hi-flow commercial units are 5 years) from a trusted brands, then give our sales team a call on 01202 822221 or use our contact us form. Follow us on Facebook or Twitter for our latest offers. We produce full VAT invoices for all sales.

Direct hot water system? features and benefits

Direct hot water system ? What are they ? 

A direct-fired hot water system is powered by a direct-fired water heater, whereby the water’s heat source is physically contained within the hot water cylinder itself.

As such, a direct fired hot water heater has a built-in gas or oil burner or electric immersion heater elements that directly heats the domestic hot water.

Thus, the water in a direct hot water heating system is heated by heat sources physically located within the hot water cylinder or calorifier as opposed to an indirect hot water cylinder, which generally speaking use a water supply from another heat source to heat the water via an internal coil.

A direct hot water system which is domestic hot water heating via a direct heat source such as electric immersion heaters or gas fired burners- Flexiheat UK

Direct domestic hot water heating systems to heat water

Advantages of direct hot water systems

Direct fired water heaters are devoted to the production of domestic hot water only, allowing for a quicker heat-up and response time than indirect hot water cylinders or systems, which essentially use “heating water” from a central heating system via an indirect hot water cylinder for the purpose of heating sanitary-grade hot water and are by definition less efficient.

Advantages of separating the hot water and heating systems

Direct hot water heaters are frequently placed close to the point of use, which minimises distribution heat losses and lowers the energy needed to supply water over a long pipe run. Additionally, by doing this, the system’s dead legs and portions of inactive or infrequently used pipes that represent a Legionella danger are reduced in length.

The Health and Safety Executive L8: Approved Code of Practise and Guidance for the Control of Legionella Bacteria in Water Systems, which specifies that the distribution pipework should be adequately designed to enable the water to reach all outlets at 50°C within one minute of turning on the taps, supports compliance with regulations such as this.

Gas fired direct hot water heaters

Direct gas fired hot water systems consist of an integrated gas burner that can be powered by natural gas or LPG (propane) gas that heats the water in the storage vessel directly to produce domestic hot water, controlled by a thermostat in the water heater.

They function by delivering heated gases through the heat exchanger, which is normally an internal coil or may be fire tubes located within the hot water cylinder to heat water. The heat from the heat exchanger is then transferred to the cold water surrounding it, thus heating the water to the desired temperature in an energy-efficient manner.

Indirect hot water systems

A dedicated central heating hot water boiler and an indirect hot water cylinder would be installed in an indirect hot water system. The same boiler is now capable of serving both the heating circuit and the domestic hot water system. When no space heating is required, the boiler must continue functioning to produce heat for the domestic hot water system.

Generally, indirect cylinders also come with an immersion heater or immersion heaters as an emergency backup, heating the water directly in the cylinder in the event of a fault with the heating boiler.

What is a direct hot water cylinder?

A direct hot water cylinder: A direct hot water cylinder heats the water using heat sources that are directly located within the cylinder, such as an electric immersion heater. These hot water heating systems are typically found in buildings that do not have access to gas or would prefer to use electricity as the primary energy source for environmental reasons such as low or zero carbon emissions.

Direct cylinders are available for domestic applications. We go into more depth here –

Direct hot water cylinder range from 80 to 500 Litres

or our commercial and industrial direct hot water cylinder range, which can be fitted with large immersion heating elements and store hot water up to 5,000 litres in volume. More on this range here –

Commercial and industrial direct cylinder / tank range

Storage Direct and Indirect Hot Water Cylinders

Direct or indirect heating of your hot water cylinder depends on your requirements and site conditions; either way, Flexiheat UK has a solution for you, as we have both an indirect hot water cylinder range and a direct hot water cylinder range to suit all your calorifiers requirements.

Contact our sales team at 01202 822221 or use our email contact form for further assistance.