asked the Secretary of State for Energy if he will publish a table in the Official Report showing the average amount of heat generated from normal household appliances per £1 charged at current prices from the use of oil fuel, gas and electricity, or as nearly as possible from such figures as are available to him.
Because of the great variety of tariffs and types of heating appliances and the many different ways in which such appliances are used, it is not possible to provide any precise and universally acceptable figures about the heating performance of domestic appliances.However, the following table gives some ranges of typical average figures for the amount of heat generated from some appliances per £1 expenditure on fuel and power. These figures are no more than an illustration of the kind of differences one might expect between appliances, and it is not possible at present to deduce any single average value.
| Heat emitted per £1 expenditure on fuel or power at February 1975 prices | |
| Therms/£1 | |
| Domestic central heating | |
| Electric off-peak storage heaters | 5 –6 |
| Gas fired central heating | 4½–6½ |
| Oil-fired central heating | 4 –4½ |
| Solid fuel fired central heating | 5 –8 |
| Domestic room heaters (exclusive of water heating) | About |
| Electric fires (radiant and convective) | 2·5 |
| Gas fires (combined radiant and convective) | 3 –6 |
| Paraffin heaters (flueless) | 4 –5 |
| Solid fuel open grate fires | 3 –4 |