SCIENTIST'S EXPERIMENT

Evening Post, Volume CXI, Issue 19, 23 January 1926, Page 7

SCIENTIST'S EXPERIMENT

ELECTRICITY AND THE

HOME

THE PROBLEM OF THE WATER

BOILER

COST OF AN "ALL-ELECTKIC"

HOUSE,

(From Our Own Correspondent.) LONDON, 11th December.

Dr. 8. Parker Smith, Professor of Electrical Engineering at Glasgow, felt that he ought to have enough faith in his convictions and calculations to put them to the test, so he built himself an all-electric house, and has now been living in it for a year.

Lighting, heating, cooking are all by electricity. There are no comp:jmises. Incidentally there are no chimneys to his house —only three ventilators. The house has nine large living-rooms, and a kitchen which includes several other domestic compartments. A constant supply of hot water sufficient for all domestic purposes and for two hot baths per day was kept throughout the year and the cost of electricity for the year for a family of six has been £43 Bs, or 2s 4Jd per day or 4sd per par-' son per day. Considering his experiment of public importance, Professor Smith gave an illustrated lecture on the subject to a very well-attended meeting of the Institute of Electrical Engineers. The lecture will, no doubt, appear in due course in the journal of the institution. In view of the growing dependence of Now Zealand upon water-generated electricity the subject seems of particular interest to people in the Dominion.

"The house," said Professor Smith, "was built to be a home and not a showroom. This is an important point in determining the capital cost of an all-electric house, for in addition to the increased convenience of life obtainable with essential apparatus such as electric cookers, fires, etc., there are many available and possibly desirable appliances such as hair-driers, bed-warmera, etc., which cannot be' legitimately included under capital cost. After careful consideration, and taking into account that many appliances can be hired, I tm of the opinion that the cost of the house was 3 to 4 per cent, higher that it would, have been with ordinary coal and gas appliances and electric lighting. It must, however, be remembered that the architect can effect, many small saving; for example, neither coalhouse nor scullery is needed, also no restriction is plac 'd on the design by the position of the flues; etc."

The house contains three receptionrooms and kitchen on the ground floor, five bedrooms on the first floor, and a, large attic nursery. There is no scullery or washhouse. No provision is made for coal storage. The three external chimney breasts usod as ventilators can be used at chimneys if coal fires were used. Thero are no mantelpieces or overmantels, but fireplace recesses have been retained owing to the common practice of sitting round a fire. Separate meters were installed for registering tho respective consumptions for heating, hot water, cooking, and lighting. These meters were for experimental purposes and would not be needed for the ordinary consumer. The supply is direct current at 250 volts and the circuits are as follow: One cooker circuit wired for 30 amperes; one cooker circulifc wired for 15 amperes; one hot water circuit wired for 30 amperes; two hot water circuits wired for 15 amperes; thirty-one heating circuits wired for 15 amperes; lighting circuits, fan circuits, and bell circuits. SWITCHES AND POINTS. Switch-sockets are .used throughout. These are of the 15-ampere, 3-pin, flush pattern with a mechanical interlock to prevent the plug being removed with the switch on, or switching on before inserting tho plug. With few exceptions all switchsockets are inserted ia the skirtingboard and the switches are arranged to be put on or off by the foot. Tho object in employing sockets all of the same size is to enable all firs* and other appliances—kettle, iron, vacuum cleaner, etc—to be us«d wherever desirsd. Professor Smith V experience has shown that in the liv> ing-rooms four to five points per room are desirable. It is not unusual to have such a combination as the following in service in one room at the same time: Two fires, a desk lamp, and a tea kettle; or a fire, a toaster, a coffee percolator, and an egg boiler. In certain places it has been found convenient to duplicate some of the points by using a 15-ampere plug with a 5-ampere adaptor. THE WASHING* MACHINE ». Clothes washing is carried out in ! the kitchen. Alongside an enamelled tub a wash boiler of the percolatcr pattern has been placed. Articles, after being soapd, are placed in this i boiler, no perliminary scrubbing being 1 necessary, as the washing is done l.y tho continuous circulation of the boiiing water. Unpleasant steaming is | avoided by controling the heat; and after .bringing the water to the boil the process is usually completed in half an hour with the rotary switch on "low." Drying facilities become essential in a wet climate. For this purpose a drying-closet has been provided. The clothes are hung over ten wooden rods, while an exhaust fan draws air from the space below the floor. On entering this closet the air passes over an air warmer of the convector type, rated at lik.w. After an hour the dried clothes come out as fresh as i£ they had been 'hung out in sunshine. Not. only is this drying closet a convenience at all times for sundry articles, but it is a vast improvement on the unsightly poles and pulleys often seen in kitchens, ELECTRIC COOKING. " Electric cooking," snid the lecturer, '' well merits the success it has gained. The absence of smell, smoke, dirt, and fumes, shows that many objectionable odours commonly associated with cooking are avoidable. Indeed, it is probable that with electric; cooking much less will bn heard of tin- "nasty smell of cooking throughout the house." Smell there mny be, but not the nasty smell which is so repugnant. Other merits of electric cooking rapidly discovered are simplicity; in working aad

easo in obtciuing good results. The thermometer on the oven door and the clock enable results to'be obtained which will be particularly appreciated by the large and growing number of educated and refined women who have to do their own cooking—indeed, it may not be an exaggeration to say that the splendid results obtainable may make cooking attractive to many intelligent people. "The cooker installed is of the table type; that is, the oven is alongside the boiling-table. This avoids stooping or kneeling when attending to the oven—the low oven seems to be designed to cause irritation. The oven and the griller can be given unstinted praise. The boi«*ng plates, though satisfactory when properly maintained, require further improvements and manufacturers must try to do better. Safety and speed are the ideals at which to aim. Instead of the present inefficient boiling plates, may it not be better to use a number of economical cooking utensils each with its own heating element, like a kettle, and fitted with watertight plugs? The idea, though old, is at least worth consideration." HOT WATER SUPPLY. Professor Smith Bolved the difficult question of hot water supply by taking the electric current between 11 p.m. and 7 a.m., when the Corporation now sell it at 0.375 d per unit. In order to make the experiment successful it was necessary to obtain a welllagged tank. For several weeks tests were made with different forms of lagging until at last it was found that with a suitable application of cork the fall in temperature of the water was less than 1 degree F. per hour. Further, it was found that by proper design the amount of mixing of the incoming cold water with tho hot water in the tank could be made negligible. The tank installed is fed from the cistern, and has a cubical capacity of 87 gallons. It supplies the bath and hand-basin in the bathroom, the maid's room, pantry, cloakroom, and three points in the kitchen. Near the bottom of the tank there are immersion heateri rated for 4 k.w., 2 k.w., and 1 k.w. Near the top of the tank there is an emergency immersion heater rated at 2 k.w. This auxiliary heater has proved to be very serviceable when the demand for hot water has been exceptional, and the temperature has fallen too low for domestic purposes* For instance, it will h»at up sufficient water for a 35 to 40-gallon warm bath in 30 to 60 minutes, according to the water temperature when switching on. A COMPARISON. "As regards the consumer," said the lecturer, "the first question Will probably be that of relative costs, apart from merit* and demerits. Now, a true and fair comparison can scarcely be made unless corresponding costs are available for similar services obtained from coal, gas and electricity in some combination or other. Unfortunately, not many householders keep sufficient data to check their annual expenditure on coal, coke, anthracite, gas, oil, candies, firewood, matches, etc. A fair estimate can, however, be made when some of the smaller items are omitted, though there are doubtless many cases where it would be irksome to keep accurate accounts, e.g., where coal is purchased in small quantities. Nevertheless, such information is needful wherever fair comparisons are to be made. In the author's case, the allelectric house in Glasgow cost practically the same as a somewhat smaller house in Wimbledon, in which coal, gas, and electricity together cost £42 and £45 in two successive years. Here, however, much less hot water was obtained." ANALYSIS OP COST. The lecturer gave the following tables:— TABLE 1. / All-electric House (10 Booms). Energy costs for 52 weeks (* quarters), 12th July, 1924, 11th July, 1925. Six persons in house, excluding euests. Main 2-rate meter: — & «. d. Fixed charge 12 10 0 Day load, 10,299 units at m 0.5 d2l 9 2 Night load, 6043 units at 0.375 d 9 8 10 Total cost for year . 43 8 0 Average^ cost per week, 16s Bd. Average cost per day, 2s 4Jd. Average cost per day per person, 4}d. Average cost per unit, day consumption, 0.791 d. , Average cost per unit, total con. sumption, 0.637 d. TABLE 2. •'■ Analysis of Consumption in Units.

«S a 2 a £ 3 ~2 I sep»»temet«ri. g $ |f fe| . Seating .. 5954 114 16 2.74 Sot water . 1243 (day) 6045 140 20 3.33 (night): 3ooking .... 2777 53 7.5 1.27 lighting ... 568 11 1.5 0.26 Total ... 16584 318 45 7.60 85, Fleet itreet.