What is a heat pump?

 

In simple terms, an airothermic or aerothermic heat pump works a bit like a freezer in reverse. The unit contains a refrigerant, which absorbs heat energy from the air around it. That energy is transferred to a water/antifreeze mixture in a heat exchanger mounted inside the heat pump casing. The heated water mixture is pumped back to regulation unit and then around the house to warm it to a comfortable living temperature. The system is reversible, such that in the summer chilled water can be pumped around the system thus cooling and refreshing the rooms.

Underfloor pipework being stapled to the insulation:

 

Two zones of 16mm PVC pipe on a base of 40mm foam insulation:

 

An airothermic heat pump as installed by Masters Electricite. The large bore pipes at the side carry the water/antifreeze solution to and from the regulation module:

 

The water solution can be circulated around the house in two ways.  One is through a network of pipes laid in the concrete floor screed below the tiles.  The second is through the use of fan-assisted ventilators positioned in a similar position to conventional radiators.  The under floor method is more appropriate in new buildings or properties undergoing major renovations.  It is particular well adapted to barn conversions, as these are traditionally designed with high ceilings and are therefore difficult to heat effectively in a conventional manner.

One of the biggest advantages of this kind of system is running cost. Based on an average new house of 130m², the annual cost of heating would be more than twice as expensive with oil and over three times the cost using propane gas. This data was drawn from 2005 prices, since then the price of oil and gas has risen dramatically further expanding the difference.

Another significant factor is the benefit to the environment. For every 1kW of energy consumed the heat pump produces 3kW. There are no by-products exhausted into the atmosphere and its principal source of energy is free: the heat contained in the surrounding air.

Furthermore since the system is reversible, there is only a single investment for both heating and cooling your house.

If the house is your principal residence you may also benefit from a French government tax credit of 50% of the cost of the pump and regulation module.