Comparison with traditional cooling and heating systems
Open plan office
Main duct and outlets
Perimeter outlets
Whereas a wall mounted unit or radiator provides a single point of distribution for heating or the cooling, a similar sized 10kW Hi-Velocity mini duct system will have up to 45 points of distribution.
This multipoint distribution provides even temperatures throughout the whole area, with no draughts. The room occupants feel comfortable at all times.
Traditional cooling systems
A typical 10m x 6m office space requires 7 -10 kW of cooling to reduce the room temperature sufficiently to achieve a comfortable environment.
The cheapest traditional solution would be a single ceiling cassette or wall mounted split system, positioned centrally within the space or a pair of units each delivering half the required duty.
These traditional cooling systems work by having an intake point and an exhaust point. A built in fan motor creates the air movement. Air within the space is drawn towards the fan coil and taken in. It is then pulled across a refrigerant coil and blown out at a reduced temperature.
This can create draughts and be uncomfortable for the person sitting in the path of the cold air.
Traditional heating systems
Central heating
A typical 10m x 6m office space with a 2.5m ceiling would require four radiators positioned at 1/3 and 2/3 intervals along both of the longer walls to distribute heat.
Central heating delivers heated water around a loop of insulated copper pipework connected to delivery points, i.e. the radiators. Each radiator is made up of fins of metal that heat up when hot water is passed through them. They heat the room using convection. Convection is the reason why fire travels much faster upwards than to the sides.
Radiators only heat the space directly around them. This space has a higher temperature than areas further away, particularly at low level. They are unable to draw the cooler air from around the room towards them, except for the convection effect. Anyone sitting near a radiator will get too hot. The time taken to heat the whole room can be considerable as there is no air movement in the middle of the room.
Air movement is only caused by people moving around or by a separate ventilation system.
Under floor heating
Under floor heating has the advantage of having no radiators, thus freeing up wall space. Systems are electric or water. Electric systems are cheap to buy but can be expensive to run. Water systems use pipework under the floor, which is set into a concrete screed.
In both cases the time taken to achieve even temperatures, the lack of control for individual areas, hot feet and the lack of cooling option are potential drawbacks.
Under floor heating is rarely an option for commercial applications. Although popular for residential applications, it means a completely separate cooling system will be required if air conditioning is to be installed.