ALL TEMPERATURES UNDER CONTROL

Press, Volume CVIII, Issue 31657, 18 April 1968, Page 23

ALL TEMPERATURES UNDER CONTROL

HAVE YOU GOT THINGS UNDER CONTROL? Of all the services which we take for granted in this modern day and age electricity must surely head the list. Turn a knob, push a button, or flick a switch and you put into operation the most efficient, silent domestic servant available. Why is it then that

we often hear the remark that electricity —the fuel which is 100 per cent efficient —is “too expensive for central heating?” The reason is invariably due to its control; or more correctly, its lack of control. During the last few years it has been proved that electricity compares very favourably with any other fuel for

domestic central heating and, in addition, the lower installation costs have to be taken into consideration. These costs are at a minimum during the construction of a new house and the modern trend of dispensing with a fireplace and chimney results in savings which go a long way towards the capital cost of electric central heating.

Perhaps “central heating” is not the best term to apply to the complete heating of a house by electricity as it implies heating from a central point. The term “zoned heating” would be more accurate for electricity and particularly when electric skirting heaters and low voltage control equipment are employed. With this type of equipment not only is each zone, or room, controlled to a remarkable degree of accuracy, but the householder is also able to select precisely the heat he requires in each room. It cannot be too strongly emphasised to home-owners considering whole house heating that they should obtain advice from authoritative sources. The major manufacturers of heating equipment run free advisory services and they, or their agents, should be approached so that they receive a proper heating submission for their particular house. The heat losses in every house vary, depending on the type of construction, insulating materials, the prevailing outside temperatures, and so on, and an incorrect calculation of the heating required can result in inefficient heating, waste of electric power and high power bills.

Consumers who have used portable electric heaters in the past have noticed a tremendous increase in their power bills; if the same number of kilowatts had been employed economically and controlled automatically then they would have not only decreased power bills but

controlled temperatures at the correct levels. It is now generally recognised by architects, consultants and the heating industry that automatic control of heat output is absolutely vital and the more accurate the control equipment the greater the reduction in the consumer’s power accounts. Consumers may well intend to “turn the heat down” but in practice they seldom do and uncontrolled or manual, switch-operated heating invariably leads to the maintanence of unnecessarily excessive temperatures. Modern control devices will do everything, automatically, and thus bypass the human element. Such control equipment is now available in New Zealand from North America and works on 24 volts only. The biggest single feature of all these lowvoltage controls is their extreme accuracy—to within | degree Fahrenheit. However, one of the most important advantages of this equipment is the system whereby all rooms, or zones, within a home can now be controlled from one point by means of a master control panel, which is usually situated in a central position such as the hallway. Each individual room can be separately controlled from this central control panel to any temperature desired and each room, or zone, has a “night set back” setting. The function of this can possibly best be explained by example.

The house-owner has decided by experiment that the most comfort-

able temperature for his lounge is 72 degrees F. The lounge is, however, only used during the late afternoon and the evening; for the rest of the time he does not want his lounge at this temperature, neither does he want to switch the heat of completely and be faced with the added expense of heating up the atmosphere in the room plus the cold walls, ceiling, and so on, when it is switched on again. With the low voltage control system all that he need do is, on passing the control panel in the hall on his way to bed, to switch the knob marked “lounge” to “night.” This automatically works a device in the thermostat in the lounge so that although it is still set at 72 degrees it controls at 10 degress less, until the knob on the control panel is switched back to the “day” setting, which would possibly be about 3 o’clock the next afternoon. Similarly any zone can be switched to the economic “tick over” temperature when not in use, from the central control panel.

Apart from the domestic applications of the above system it produces demonstrable advantages—in the saving of electricity and therefore costs—for motels and hotels, for, when the guest checks out or leaves his key at the reception desk on going out for the day the receptionist can, from the panel by her desk, reduce the temperature of the unused room by 10 degrees, or switch off the heat completely, until it is again occupied.

A further refinement is the use of a time clock or switch; this can be employed to switch all or part of a heating installation on and off automatically, at the times that it has been found from experiment are the most suitable. Having dealt with the control of heat let us now look briefly at the source of the heat which we are controlling—namely, the skirt-ing-board heater. This should normally be on a cold wall or underneath a window where it fits snugly and unobtrusively above the skirt-ing-board. When considering the use of skirting-board heaters, the essential criterion should be, not the length of the heater or its cost per foot, but the heat output in watts per foot.

It is obviously undesirable, and in many cases impractical, to use heaters which are

longer than is necessary for the wattage required and the best designs of skirting heaters will produce in excess of 300 watts per foot. This again underlines the necessity of obtaining correct advice from a reputable source and this is where the free advisory service, mentioned above, pays dividends to the home-owner whether he be wanting to heat a house to be constructed or his existing home. After all, the best advertisement which a manufacturer can have is satisfied clients and these can best be obtained by ensuring the correct use of the equipment purchased.