Cool heat

In answer to Dave Draper's question (Letters, 1 June).

The absorption refrigeration system is unsuitable for cars because the power-to-weight ratio is too low.

To produce the same amount of cooling as a compression refrigeration system would require an absorption cooler the size of the car on top of the car.

Where Draper is right is in identifying this type of refrigeration system as a good way of producing cooling from waste heat. As such, it is ideal for producing domestic and commercial cooling where waste heat is available.

Alternatively, it can produce cooling from sunlight as in our system at Solar Polar.

Michael Reid, Peterborough