Getting the design and specification of an integrated BHU slightly wrong in a large industrial or commercial space can magnify any deficiency in the performance of the system in terms of efficiency, cost and non compliance.

Ultimately, there are 2 basic concepts to consider initially, these being warm air heating and radiant heating systems

Warm Air Heating
Warm air heating as the name suggests delivers warm air directly into the building. Numerous types of “off the shelf” warm air heaters are available from suspended unit heater types and floor mounted units which can be located internally or externally together with bespoke hybrid system solutions.

Fundamentally, this air needs to be distributed and the units can be free blowing or ducted to distribute the airflow evenly.  But, as we know “warm air rises” so it is fair to say that with all conventional gas fired warm air unit heaters then destratification systems should also be used to maximise efficiencies and ensure an even temperature distribution.

Where more bespoke warm air heating systems are utilised, such as an air handling system, then the supply air temperature can be more easily controlled, thus limiting stratification. However, the capital cost of such systems are likely to be more than a unit heater approach.

Warm air heating utilising high velocity ductwork distribution systems can also be utilised and has been a popular choice in recent years for providing an efficient method of heating and cooling large warehouses.  The advantages of such systems is that a higher velocity of air allows ductwork sizes to be minimised and the use of nozzle type diffusers which inject air into the space at a high velocity thus entraining the high level surrounding air as it does so to create an even temperature distribution in the building.  Also, these system types do not allow for internal layout changes easily and recent EU directives provide challenges to this system type efficiency.

In response to this challenge the principle of air rotation is increasing in popularity now in the UK to address this problem. The principle is to move large volumes of air at a low velocity and at a controlled temperature.  The heater draws in cooler air at floor level which is then heated and discharged at high level effectively destratifying the building and creating an even temperature distribution.

The advantage of such system types allows 1 heater to heat a large space where previously 3 or 4 heaters with a destratification system would be required. Therefore, capital costs are lower, installation time is faster, no ductwork is required, efficiency is high and a lower maintenance cost.

Radiant Heating
Finally, we have radiant type heaters which very efficiently heat large buildings as they do not heat the air directly.  Working as the sun works, Radiant heaters produce infrared heat that does not heat the air directly but heats the surfaces, people and solid objects in its path which in turn creates an all round radiant warmth at a lower air temperature than would be required with a warm air type system.

This technology provides low running costs, is excellent for spot heating, provides rapid and almost instantaneous heat, is great for buildings with high infiltration and can be easily controlled in zones.

Control Systems
The importance of control with all system types should not be overlooked. It’s imperative that energy efficient controls are selected and implemented to ensure maximum efficiency is achieved, monitored and maintained with any system consideration.

Cosaf have successfully developed and evolved the technology to cater for any challenge and can advise in the design, specification and retro-fit options for optimising the control systems needed to improve performance and monitoring.

Cosaf specialise in designing, specifying, installing and maintaining commercial and industrial heating solutions for the manufacturing, pharmaceutical, food & beverage and large office/ warehouse environments. Find out more by clicking the links below