Refinements in coal firing

Press, Volume CXI, Issue 32587, 22 April 1971, Page 19

Refinements in coal firing

Attractive, appropriate for modern decor the Visor coal-fired heater is an open fire heater which stands out in the middle of a room. Cheap to buy, economic to install, and offering the additional economy of coal as its fuel, this type has its efficiency increased by the heat radiated from the metal flue passing through the ceiling.

This modem type of open fire is not the only improvement to the traditional means of heating a home. In the conventional open fire there have been refinements in design of chimneys and of fireplaces. Convector flue ways are provided on some recent designs, improving the efficiency. Grates certainly have not changed much except for the provision, in some cases, of a controlled air supply under the grate. The simple colonial grate and the basket type still remain very popular forms.

This conventional open fire can be used with a wet-back for further savings in heating costs. These are generally used only for the heating of the water cylinder.

. They can provide normally all the domestic hot water a

family needs without relying lon the electric element.

A popular enlarged version of the wet-back is the Ryax system. In this case, the wet? back is really a small boiler which fits in behind the open fire. The resulting hot water is used for the domestic cylinder and it is also pumped round the house to a series of five or six radiators to give whole house heating.

Of course, there is the chip heater, or destructor, normally set in the kitchen for such domestic water heating. It bums rubbish and almost anything put in it.

Offering more efficiency (therefore greater savings), is the space heater. This is a self-contained heater sometimes called a slow combustion stove or closed stove. It can be built in or free-stand-ing, but when built in converted air can be drawn in and round the heater. This air is warmed and discharged into the room. Normally the heat output is regulated by a control on the air supply to the heater. Most space heaters have attachments for water heating as an optional extra.

Most importantly, space heaters do no do away with the presence of living flames, the psychological attraction which is an enduring feature of coal for home heating. All the space heaters available have windows of heat resistant glass. The flames are visible through this glass and the traditional concept of the open fire is largely retained.

The Continental downdraught heater is a very good type of domestic space heater. The only type available is the Juno, of German design, made in New Zealand under licence. There will.be

a great future for this type of space heater in New Zealand because it has been designed to bum the type of coal available in New Zealand. It is a free-standing unit. It needs charging with fuel only once a day, and the output is regulated by its thermostat. It works on a down-draught principle to give a minimum of smoke emission.

In the tests which have been carried out, the measured efficiencies have always exceeded 70 per cent. The output of the heater at a high setting of the regulator is sufficient to supply some degree of whole-house heating if the space heater is suitably placed in the house and if doors are left open to permit the circulation of hot air round the house.

Coal can offer central heating for the home also. There

has been a coal-fired hot air appliance for many years. Hot water central heating systems seem to be preferred; this trend from hot air to hot water is becoming evident with all fuels. A small boiler is automatically controlled; and a pump circuit supplies hot water round the house to steel radiators.

A word of warning with whole-house central heating —it is not cheap. The total capital cost is S7OO or SBOO, and, even with the cheapest coal available, fuel bills are generally higher than the installer first imagines. Such central heating systems whether with oil or coal, do provide sophisticated comfort, but you have got to pay for this sophistication.

(From the information and I press section, publicity divis- 1 ion of the Coal Districts Wei- i fare and Research Council.) >