asked the Secretary of State for Energy what is his estimate of the heat generated in British thermal units by various privately-owned oil-fired central heating units.

The total annual domestic fuel consumption by oil-fired central heating units in all houses and other dwellings was nearly 2·9 million tons in 1973, equivalent to nearly 130 million million BTUs or 1,300 million therms.

asked the Secretary of State for Energy what encouragement Her Majesty's Government have given since March 1974 to the development of a heat pump to provide low temperature heat for central heating systems.

I have been asked to reply.A team of scientists at the Building Research Establishment is engaged in a review of experience with heat pumps in this country and elsewhere, with the aim of determining the best way in which they could be used in building services within the United Kingdom. The object is to specify equipment suitable for use in dwellings, and information will be disseminated so as to encourage the adoption of heat pumps wherever appropriate.The Government are also investigating the possibility of wider adoption of the heat pump in industrial and commercial buildings, and a review is in progress with the Property Services Agency to ascertain whether wider use would now be justified in Government buildings.