DOMESTIC HEATING APPLIANCES (EFFICIENCY) (Hansard, 15 February 1951)

§ Mr. Pitman
asked the Lord President of the Council whether he is now in a position to furnish figures in regard to the efficiency of various methods of continuous room heating.

§ Mr. H. Morrison
The latest information available to the Department of Scientific and Industrial Research on efficiencies of various types of modern domestic heating appliances is given below. It is, of course, impossible to give one figure for each type of appliance that represents the diverse advantages and disadvantages of the different methods of heating. Even the overall percentage of efficiency with which heat from the original raw coal is made available for the continuous heating of a house with an internal flue depends on a number of factors.
108W

§ Mr. Webb
The allocations of sugar to the principal using industries in 1951 are given below along with a comparison of the percentage of datum usage, where appropriate, between 1950 and 1951.
The table below is based on published figures for the efficiency with which gas, coke and electricity are produced from coal, and on experimental results obtained at the Building Research and Fuel Research Stations of the D.S.I.R. for the efficiency of modern appliances in the house. The final figures must, however, be treated with reserve, since the types of fuel used in power stations are not generally suitable for direct domestic use, and since the amount of heat derived from the appliances depends, with solid fuel appliances, on their type, on the skill with which they are used, on the grade of fuel employed and, with both gas and solid fuel appliances, on the rate of air flow up the flue. The figures apply only to continuous room heating, and, of course, take no account of convenience, cleanliness or other 109W amenities; nor do they reflect the relative net costs to the consumer, which are affected by many other factors. The figures in the table must therefore be considered with these reservations.

EFFICIENCIES OF METHODS OF CONTINUOUS ROOM HEATING

— COAL (in closeable open fire) COKE (in closeable open fire) GAS (in convector fire) ELECTRICITY

(1) (2) (1) (2)

(a) Percentage of potential heat in original coal available at appliance, (neglecting losses of coal in transit) 100 73(3) 100 73 (3) 48 (3) 20 (3)

(b) Efficiency of good modern appliance, i.e., percentage of (a) delivered as effective heat by the appliance to the house, (including heat gained from flue) 50–60 60–70 60–70 60–70 60–70 100

(c) Overall efficiency (percentage) with which potential heat in original coal is delivered as effective heat in the house (a) × (b) 50–60 44–51 60–70 44–51 29–34 20

(1) The figures in these columns are based on the convention that gas and coke are both produced with the same efficiency.

(2) In these columns the alternative convention has been adopted of debiting the whole of the heat loss at the gasworks, to gas and assuming that the coke is produced with 100 per cent efficiency.

(3) These figures are averages for the whole country. The figures will become appreciably higher as installation of the most modern types of gasworks and power stations progresses. The figures in the columns headed "coke" and "gas" are taken from the report of the Heating and Ventilating Committee and relate to 1937. The figure for electricity is taken from the Report of the B.E.A. for 1949–50.

EFFICIENCIES OF METHODS OF CONTINUOUS ROOM HEATING
—	COAL (in closeable open fire)	COKE (in closeable open fire)	GAS (in convector fire)	ELECTRICITY
		(1)	(2)	(1)	(2)
(a) Percentage of potential heat in original coal available at appliance, (neglecting losses of coal in transit)	100	73(3)	100	73 (3)	48 (3)	20 (3)
(b) Efficiency of good modern appliance, i.e., percentage of (a) delivered as effective heat by the appliance to the house, (including heat gained from flue)	50–60	60–70	60–70	60–70	60–70	100
(c) Overall efficiency (percentage) with which potential heat in original coal is delivered as effective heat in the house (a) × (b)	50–60	44–51	60–70	44–51	29–34	20
(1) The figures in these columns are based on the convention that gas and coke are both produced with the same efficiency.
(2) In these columns the alternative convention has been adopted of debiting the whole of the heat loss at the gasworks, to gas and assuming that the coke is produced with 100 per cent efficiency.
(3) These figures are averages for the whole country. The figures will become appreciably higher as installation of the most modern types of gasworks and power stations progresses. The figures in the columns headed "coke" and "gas" are taken from the report of the Heating and Ventilating Committee and relate to 1937. The figure for electricity is taken from the Report of the B.E.A. for 1949–50.