Consuming Interest

Heating

By LESLIE ADRIAN During the past few years a lot of work has been done on the small-bore pipe system of cen- tral heating, which is said to be cheaper and in many ways more effective than the old large-pipe system installed in some big houses. Only in tall two- or three-storey houses is it possible to get a really good 'head' of circulation to ensure a satis- factory convection flow round the whole circuit. The wide bore of the pipes is demanded by the need to reduce resistance to flow, and small circuits are most economical. With the small pipe, using copper, which is resistant to acid waters, less metal is used, which lowers the initial cost, and a pump keeps the flow constant. Modern glandless pumps are leakproof, vibration-free and practically noise- less, and their electricity consumption can be as little as one kilowatt-hour in 24 hours for a medium-sized house. Naturally, the cost will de- pend on the heat losses of the building itself, and upon the method of water heating employed.

There is much that could be said here about in- sulation, so little understood in Britain that legis- lation has been necessary to compel proprietors of industrial buildings to do something about wasted heat. 1 hope to deal later with the domes- tic aspects of this complex subject.

Meanwhile I have been trying to discover some basis on which to compare the costs for different fuels heating an average size small-bore hot-water system. When looking at the bare figures (which can only be approximate) remember that there are 'non-monetary' advantages as well. For in- stance, with gas or electricity there are no storage or ash-disposal problems, and no stoking. With oil, an external storage tank is obligatory. With solid fuels there are gravity feed and other semi- automatic systems of stoking, but they are gener- ally available on the large boilers only, and ash has still to be got rid of. First, the cost of installation. Rarely will it he under £200 to £250 in a new house, and in one already built it could be as -high as £4504500, depending on the floor area. This excludes roof insulation, automatic switching and the cost of hot-water pipes from the cylinder to the fittings. Partial central heating with large-bore systems (indirect for preference) is, of course, cheaper.

The Coal Utilisation Council publish a folder (from 3 Upper Belgrave Street, London, SW I) showing comparative central-heating and hot- water costs for the four basic types of fuel. Assuming a weekly consumption of 30 therms (3 million B.t.u.) in a small house in cold weather, a boiler with an hourly rating of 45,000 B.t.u., would be needed. By 'small house' is meant .three bedrooms; about 1,000-1,200 sq. ft. of floor space. Weekly cost is based on a fifteen-hour day and a thirty-week.heating season, of which four weeks are at maximum heat, eight at three-quar- ters and eighteen at half of maximum. There is still heat loss to consider, but it is so variable that the CUC have to leave it out of the calculation.

With solid fuel costing £8 a ton, the weekly cost of using coal in a hand-fired sectional boiler (the usual method) would be 18s. 8d.; using an- thracite in a gravity-feed boiler, 13s. 4d. The cost of coke is not given for this rating of boiler, but for a boiler rated at 100,000 B.t.u. an hour (hand- fired) the weekly cost of burning coke at £8 a ton would be 50s. 8d.. coal (underfeed stoker) 46s. 7d., and anthracite (gravity feed) 34s. 8d. These discrep- ancies arise from the great differences in thermal efficiency of the three fuels. Quality for quality, the variation can be as much as 30 per cent., and the burning efficiency of the appliance can differ by 10-15 per cent. between a hand-fired boiler and the gravity-feed type.

Reverting to the small house example, the weekly cost of gas (excluding the standing charge) runs from 25s. 3d. for Is. Id. a therm districts (if any) to 46s. 8d. where it costs as much as 2s. a therm. Electricity (ignoring standing charges again) varies from 31s. ltd. a week where the unit charge is 0.7d. to 57s. where the unit costs

The weekly cost of burning oil in a sectional boiler with a simple burner can vary from 28s. 8d., using cheap oil at ls. 31d. a gallon, to 35s.' ld. using oil at Is. 7d. a gallon. Again the thermal efficiency of both town gases and fuel oils varies quite widely, and cheapness is no criterion for preference. With oil the user has a choice, of course. With town gas it's take it or burn sortie' thing else.

It is clear that the solid fuels are cheaper la more trouble, just as electricity and gas are th'' least trouble and the dearest. The CUC's booldc Central Heating for Houses (2s. 6d.), has usefli information on costs and is a good guide 0 modern systems. There is also a helpful chaplei in Eric Bird's House Maintenance for the hue& gent Owner (A. and C. Black, 15s.). When choos' ing appliances, consult the CUC's Approved List revised each February. Warm-air heating has made progress in recoil years in this country (I am aware that the Roman' had it). There are a number of systems available using automatic solid-fuel, oil- or gas-fired boilers. and they vary in capacity. The Potterton Minor, for instance, will do no more than supply `back" ground' warmth (usually taken to be 50-55' f.) for a small dwelling of 860-1,000 sq. ft. Prices are not quoted, again because of the varied require' ments of users.' With such installations, as with underfloor heating units (which have to go in when the house is built), it is essential to have an estimate. It is unlikely, however, that a warm-tur installation in a new house will cost much Ws than £2004300. There is little data yet on open" ating costs.

A crop of space-heating devices is now coming on the market, and I can do no more here than mention them in case a reader should spot one , them as meeting a special need. There are the dee' tric carpet heaters (big brothers of the electric blanket), actually underlays with built-in ele' ments. Among these the Isopad costs just Over £15 for an underlay measuring 9 feet by 6 feel' There is skirting heating (a form of water heatid and there is electrical wall heating. There are till new panel radiators, no more than j inch thick for water-heating systems, and the tubular etc"; tric heaters, some of which are portable. The Building Centre, Store Street, is worth 3 visit by bewildered householders. The permanent exhibition is an education, and all queries are promptly, sensibly and objectively answered.

Cyril Ray writes: I cannot tell you what the Vintners buy one half so precious as the Good' they sell, but I can report what some of 1101 have been drinking, for I attended the dinner they gave to Mr. Alfred Langenbach, to celebrate his eightieth birthday, and his diamond jubilee in the wine trade. Let me not tantalise you .° smacking my lips over the Niersteiner Hipfr15 Riesling hochfeine Beerenauslese 1934, for there i is none left for you--we polished off the twenty-two bottles in the world that very night', but it is worth noting that the banquet began an': ended with sparkling wines. A light Langenbil sparkling mosel was served a.s an aperitif, an duly and deliciously freshened the palate for the fine food to follow. After dinner, with the dessert, we sat over a fuller, fruitier Langenbach; 'Privat' Brut Sekt. Both wines are available 3 about a guinea or 22s. a bottle—the mosel front Dolamore and from Saccone and Speed, among l others, and the hock from Hatch, Mansfield from Justerini's, I like this custom of serving sparkling wines as aperitifs and desserts, and the non-vintage Germans are cheaper than chats' pagne, less austerely dry, and good value 01 money.

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