With the improvement in insulation standards and the move towards producing air tight properties, the problem of air quality has become an issue.
In the past, Building Regulations required extract fans in wet areas such as bathrooms and kitchens to remove the warm moist air and prevent condensation. The improvement in weather seals around doors and windows prevented fresh air from entering the building and with the need for extractor fans the Building Regulations then introduced trickle vents to windows to provide the necessary air changes.
The consequence of this was that although condensation was considerably reduced, the continuous air changes within the building removed a large proportion of the heat.
With the increase in wood burning appliances the further requirement for combustion air also led to more cold air being introduced. However, there are now many stoves on the market which can be connected directly to a ducted fresh air supply to allow efficient combustion and do not introduce cold fresh air into the room.
As a way of overcoming all these problems, heat recovery units are now being fitted to new and existing homes. They are particularly relevant where the properties are required to meet the new standards for sustainable homes.
A unit is generally fitted to the loft area with two vents to the outside. Warm moist air is extracted from the wet areas of a building, e.g. utility, kitchen. bathroom and particularly shower rooms. This air passes into the unit across a very efficient heat exchanger where up to 92% of the heat is extracted and transferred to fresh air being drawn in from the outside. This warm dry air is then returned to the living areas of the building.
It may seem that the amount of energy required to run the fan for the unit would prove to be expensive but the introduction of DC fan motors can reduce the energy requirements to a minimum. This computes to running the unit for 200 hours at a cost of only around 11 pence. The amount of heat retained by the unit far outweighs this cost which can be further mitigated if the property fitted with solar PV panels, which produce their own electricity.
The system can be thermostatically controlled and can be operated by hand held remotes. They require minimum maintenance and depending upon usage most manufacturers suggest the filter being changed once a year. The DC motors as well as being very economical are also very quiet in operation.
The overall effect of the unit is to increase the comfort levels within the property, removing moist stale air and replacing it with pre-warmed fresh air. The saving on heating costs is significant and condensation mould is eliminated.
Systems come in various sizes and capacities depending on house type and the number of air movements required.
To find out more on the benefits of heat recovery systems and how you can integrate it into your home please contact our friendly team of experts at energy BY DESIGN .