Industrial Unit Heaters

Industrial Unit Heaters –

Industrial unit heaters water electric gas oil or steam powered from Flexiheat UK

Industrial unit heaters from Flexiheat UK

Industrial unit heaters come in a wide variety of types for the industrial heating industry, most are versatile in use to cover a wide variety of heating applications, whilst others are designed for specific or niche heating applications.

They are ideally suited to commercial or industrial space heating, as they have an integrated fan, which produces a high volume of air flow which distributes the warm air generated by these industrial unit heaters efficiently and evenly throughout the area of which the units are installed. Depending on the size of the area being heated single or multiple industrial unit heaters may be required, as the effective throw of the warm air has to be considered.

The use of an integrated fan on the unit heaters creates air movement over the heating element surface, quickly and efficiently, this factor ensures that when compared to an equivalent convector type heater, unit heaters are more compact in size, getting more effective warm air heat out of these types of industrial heaters. Our unit heaters are designed to hold up against the typical abuse often seen in commercial and industrial applications or environments being able to withstand dusty and dirty air conditions.

Industrial unit heater – sizing your warm air heating system

Sizing of the most appropriate model and quantity of these industrial unit heaters should always be done on the premises of gaining the optimum efficiency and cost effectiveness both in the initial purchase cost and also the running costs for the warm air heating system.

There are a number of factors, which effective the overall heat load requirement for any commercial or industrial building and the heat that is required to get to your desired working temperatures. The factors that influence this heat load calculation include –

  1. How well insulated the building being heated is.
  2. The amount of air changes per hour this building normally has – i.e. are large roller shutter doors open, and how often they are.
  3. What is your preferred fuel preference – as unit heaters can be fuelled by hot water, electric, steam, natural gas, propane gas or even oil – they choice may be dedicated to you by buildings location and subsequently the available fuel on site.
  4. The efficiency and level of control accuracy of the warm air heating system.
  5. The normal ambient air temperatures you are likely to see in the winter periods – This is an important factor in calculating the size and number of required unit heaters – as you want to ensure that the heating system is adequate to handle the coldest environmental conditions it will endure.
  6. The height of the building will also have an influence on the warm air system, as if the height is large, then the use of destratification fans, to push the warm air back to the ground level where it is required can be used to counter act this natural phenomenon and add to the heating system efficiency.

Should you require any more information on industrial unit heater sizing for your application, then we at Flexiheat UK would be please to help you size your particular warm air heating application. either pop us over an email to or give us a call on 01202 822221 to find out more.

Unit heater types

The heat emitted from these unit heaters can be generated by a variety of fuels, with the predominant factor often being the most readily available and or the most economical fuel source available to the premises.  The most common unit heater types are –

Hot water unit heaters – water fed unit heaters

hot water unit heaters;hydronic hot water hanging unit heater

Hot water unit heaters for LTHW/MTHW or HTHW systems from Flexiheat UK

Often called a “hot water fan heater” or “hot water air heater”- water fed commercial / industrial unit heaters are very commonly used in factories, warehouses, sports halls or workshops. The hot water is normally generated by a boiler which can be fuelled by gas , oil or electric or even a heat pump which heats the water up to the desired temperature before it is circulated via a piped heating system to the unit heaters often at a low pressure ( 3 bar or under )  – thus the term “low pressure hot water” – or LPHW air unit heaters .

They come with the various control options and ancillaries such as thermostats, which can control the operation of the unit heater fan and also can control the water flow to the unit heater by opening or closing a control valve feeding the unit. Commercial or industrial premises with multiple unit heaters can often be controlled by a single controller, which when coupled to external temperature probe can optimize or compensate for the external weather conditions and adjust the warm air heating system accordingly. This results in higher efficiency levels and reduced running cost of the commercial or industrial heating system.

These industrial unit heaters are available either with units made with plastic (EPP- expanded polypropylene) casings which ensures a modern design with high performance parameters, with outputs from 5kW to 70kW, and air flows up to 4,100 M3/hr or with metal casings with outputs from 6.5 kW to 344 kW in output.

These warm water supplied unit heaters can either be suspended from the ceiling or wall mounted, allowing you to expel the warm air either vertically or horizontally to suite your site requirements

Some of our industrial unit heater range can be supplied with drip pan and drain which means they can be used not only for heating, but also for cooling applications, when supplied with a chilled water supply.

For full information on the range of water fed industrial unit heaters , please see this page of our website –

Industrial electric unit heaters

We do two ranges of industrial electric unit heaters, the first range which in reality is also suitable for commercial applications, is available with outputs from 6 kW to 15 kW. The 6 kW unit is available in either single phase or a three-phase powered model. The electric unit heaters that have a 9 kW, 12 kW or 15 kW output can only be powered by a three-phase electrical supply. This range of commercial and industrial electric unit heaters is controlled by a wireless controller, which can control any number of our electric unit heaters, up to 100 metres away from the controller location. This saves on the associated wiring and installation costs of these unit heaters.

More information and detail on this particular range of electric unit heaters can be found here –

The second range of our industrial electric unit heaters are ideally suited to industrial premises, and are not wireless controlled. They should be used to electrically heat industrial areas with relative humidity of no more than 95% and an air dust concentration of up to 3mg/m3. They come with either a slot air diffuser as standard or can be fitted with a cone air diffuser which increases the range of the warm air stream. This range of electrically powered industrial unit heaters can be installed in either a horizontal position as a ceiling mounted unit heater or in a vertical position as a wall mounted electric industrial unit heater.

Industrial electric unit heaters; unit heater electric; commercial electric unit heater

Industrial electric unit heaters from Flexiheat UK

This range has of industrial electric unit heaters, has a large range of accessories, such as roof or wall air intakes and air mixing boxes that allow the unit heater to be supplied with a mixture of fresh and recirculating air to these industrial units. They also have a range of temperature controllers that automatically changes the heat output depending on the temperature in the room and a time programmer for control of unit’s operation in a weekly mode.

For more information and detail on this particular range of electric unit heaters can be found here –

Unit Heater Types – Gas, Oil, Diesel, LPG and Propane Fired Heaters

These differ from the unit heaters mentioned previously as all of these industrial unit heaters have a combustion chamber within the heater, where the fuel is burnt and thus the heat is generated within the heater itself. They are designed for horizontal wall mounting or in vertical suspended configuration, which is useful if you are short of floor space to install a heater, or should you just want the heater up and out of the way. They have as standard an axial fan for free blowing heating applications or can be fitted with a centrifugal fan, that allows duct work to be attached to the heater, and this duct work channels the heat to the desired areas with the building.

Industrial gas unit heaters;industrial gas fired unit heaters

Industrial gas unit heaters, available in either natural gas or LPG/ propane fired from Flexiheat UK

The gas powered unit heaters , (be it natural gas or LPG / Propane) details and further information can be found here-

industrial oil unit heaters

Industrial oil unit heaters

And for the oil / diesel fired unit heaters – pictured above , the full information is here –

Industrial steam unit heaters

Steam as a medium is often seen as an old type of heating system, as it is often associated with the industrial past , but with many industrial factories using steam as part of their process – this steam is a great way of heating an industrial building , as it is exceptionally good at transferring the heat from the steam into warm air and with exceptionally fast warm up times to. Industrial steam unit heaters are very similar to water fed unit heaters, in that they have a heat exchanger coil , casing and fan assembly, but in the instance of a steam powered unit , the heat exchanger or coil itself is designed to changed the steam vapour into usable warm air energy , in in this process the steam often condenses as it transfers it energy into the air. The coils or heat exchangers used in industrial steam unit heaters must therefore be manufactured from steel with a bi-metal fin assembly to accommodate the higher pressures and temperatures associated with steam. We do a full range of steam unit heaters that have an output from 14.6 kW to 459 kW in output, depending on your steam pressure available and the entering air temperature. full detail on the range is here –

Industrial steam unit heaters

Industrial Steam Unit Heaters from Flexiheat UK

Requiring little maintenance, these steam powered industrial unit heaters are extremely tough and highly efficient, and are often wall mounted

Flexiheat UK – Your Unit Heater experts 

As you can see, we do a full range of industrial unit heaters, powered by various fuel sources, so if you have a requirement for heating an industrial or commercial building, then we will have a unit heater option to suit, so please don’t hesitate to contact us at Flexiheat UK