Bath Nights and Days

Radio Record, Volume III, Issue 44, 16 May 1930, Page 23

Bath Nights and Days

WHAT HOT. WATER WILL — COST. YOU | New System of Inéteritanedus Heating

mn arriving at a satisfactory solution a of the water-heating problem in so \far as New Zealand-and Wellington in particular-is concerned, a new chapter has been added to its history by the recent decision of the City Council electricity department to permit the installation of instantaneous heaters, under limited conditions. It may: be said at once that these tonditions are eminently reasonable, and will in no way affect the high efficiency of these heaters, which are, at the moment, practically the only means of obtaining instant hot water for baths and other household pur- _ poses, electrically. At first sight the charge per kilowatt per month, and the charge per unit of elecyricity consumed may appear to be heay, but a few moments’ consideration revéals that this charge is cencentrated on the limited number of hours (in most cases, half-hours or minutes) when the heater is actually in operation; whereas, with the employment of the storage type of heater, the lesser eost is chargeable over a much larger time, so that comparison is not necessarily unfavourable to the instantaneous type. While. supply authorities generally cannot be expected to favour this type, on account of the increase of load during the ordinary hours of demand, and the fact that it provides no outlet for night-time supply when other demands are at their lowest, it is felt that it would be unduly arbitrary to prohibit their installation. ‘From the consumers’ point of view . the instantaneous method is ideal, and

in Sydney, where several thousands are installed at ordinary rates, chiefly as bath-heaters, no serious interference with ordinary supply is experienced. Their installation is not discouraged, because they lead to a more extended use of electricity for domestic purposes. To sum up, the situation would appear to be that for those to whom an instantaneous supply of hot water is of importance at all hours, the new heaters will admirably fulfil their needs, at. a heavier rate of expense during the time they are in use, but not necessarily more expensive in the long run. In the meantime, water-heaters now in use, controlled on the thermostatic system, and charged at a flat rate per month, will continue to give admirable service, and are in many cases all that is required. Heated during the night, they are so designed that only an infinitesimal degree of heat is lost when

the current is off, and they have the added advantage of being of New Zealand manufacture. Another type, also Dominion made, for which the makers claim 25 per cent. more efficiency than any similar type on the market, is so adapted that it can be used without consumption of electricity, in conjunction with the kitchen range; or, when the range is not in use, heated electrically by the simple turn of a switch. This make, also, is proving admirably efficient in practice. Probably the greatest single source of loss to be met with in ordinary practice, where storage types are concerned, is the use of the uninsulated tank, happily now almost a thing of the past, since radiation losses from bare tanks render insulation absolutely -imperative, to attain economical heating. Another loss in efficiency occurs in localities where the water supply contains a considerable proportion of

solids, or is what is generally. termed "hard." The precipitation of these solids acceierated by heat forms scale which collects in the heating element if of the immersion type, or on the inside of the tank immediately at the back of the heater if of the clamp-on type. Its presence is generally manifested by a decrease in the supply of hot water available, or by a greater use of current for the same quantity of hot water, and its formation is so gradual that no sudden change in condition warns the user. This scale-forming effect is very greatly heightened with increased temperatures, and for that reason, if unsoftened water must be used, tank temperatures should be maintained as low as is consistent with the requirements of the service, preferably between 150 and 160 degrees Fahrenheit. It will therefore readily be seen that only rain or softened water should be used for systems of the storage tank type, wherever possible. _The actual choice of a heater resolves itself, then, into a case of studying and meeting individual and varying requirements. In all eases, the service is inexpensive for the benefits conferred, while opera~tion is highly efficient.