SAFETY ASPECTS OF HOME HEATING

Press, Volume CVI, Issue 31349, 20 April 1967, Page 27

SAFETY ASPECTS OF HOME HEATING

A householder put hot ashes from the fireplace into a cardboard box, and placed the box on top of a stack of wood in the shed attached to his house before he went to bed.

The hot ashes followed the natural course: they ignited the cardboard box, the burning box ignited the wood pile, the wood pile ignited the plywood panelling on the shed wall, the fire burnt through the shed wall into the kitchen, and the contents of the kitchen caught fire.

Fortunately the family awoke before they were overcome by smoke. But even then they tried to fight the fire before escaping or calling the fire brigade.

AU types of heating can be safe provided the appliances are installed, maintained and used with common sense and also in some cases, in accord with the rules for that type of appliance. Fires started by heaters occur in two basic ways:— By the application of a high temperature to a combustible material for a short time. For example, an elderly man accidentally

brushed against an unguarded gas fired heater igniting his pyjamas. In attempting to pull off the flaming clothing he fell down and failed to get the pyjama top over his head. He died of burns in the hospital about six weeks later. Other fires started in this way have been caused by hot coals, embers and sparks from open fires igniting furnishings. New Zealand lost £109,619 from this cause alone last year.

By exposing combustible materials such as wood to a relatively low temperature, say 250 deg. F. for a long time. For example, unusually cold weather had caused the stove in a motor parts agency building to operate almost continuously for several days. The studs to an interior temporary partition were placed very close to the steel flue near its exit from the stove. Apparently the flue ignited the studs of the partition and from them the fire spread to the racks containing cartons of motor parts. The building and contents were destroyed.

This ignition by the slow formation of pyrophoric carbon is the reason why the hot surfaces of all heaters must be shielded by baffles and air gaps from timber and other combustibles. Steam pipes are known to have caused timber one inch away to ignite after a period of years and this is why insurers require unlagged steampipes to be supported on metal brackets holding the pipe at least two inches from combustibles. Because heating appliances generate large quantities of heat the cardinal rule for heaters is that they should never be placed in a position that will prevent the adequate dissipation of their heat Any heater placed in a position where, for instance, clothing can fall on to it and block its air circulation, is a likely cause of a fire. A

recent American incident where a 79-year-old woman died of burns because her clothing ignited when she fell on to the grille of an underfloor heater and failed to get up immediately clearly illustrates this point OPEN FIRES Heating appliances can be grouped, for insurers’ requirements about precautions to be taken, by the fuel they bum and whether they are fixed or portable. For instance, most heaters burning solid fuels and fuel oil are fixed appliances requiring some type of flue to conduct the smoke and fire gases safely outside. These gases are at quite high temperatures when they leave the fire and therefore they can heat the flue up to dangerous temperatures. Open fires pass a lot of room air up the chimney with the fire gas and this has the effect of cooling it Even so, it is necessary to have a smoke-tight chimney that can be easily and regularly cleaned. These chimneys are usu-

ally of brick, concrete or pumice.

Another precaution to be taken with open fires is to prevent accumulations of combustible soot in the chimney, by avoiding smokey fires and having the chimney swept regularly. A farmer and his wife and their four children died in a farm fire in the early hours of the morning. It is thought that a log rolled from the fire in the lounge and that the whole family was axphyxlated before the fire destroyed the house. To avoid this sort of tragedy it is necessary to have a substantial and stable sparkguard that is used all the time the fire is left untend•ed. SLOW COMBUSTION STOVES

Where controlled combustion stoves and oil-burn-ing heaters are connected to chimneys, no room air passes up the chimney as a coolant and therefore in practice the flue gas and the chimney reach much higher

temperatures than they did with an open fire. Iron heating stoves such as those found in halls and industrial premises must be installed on an adequate concrete hearth which, if mounted on a wooden floor and less than four inches thick, must have a onMnch air gap between it and the floor. This hearth should extend out at least nine inches on each side of the stove and at least eighteen inches in front of the stove, preferably with a small kerb. If the stove is within twelve inches of any combustible material it must be shielded with an incombustible baffle placed so that the baffle is at least five inches from the stove and has an air gap of at least one inch between it and the combustible material. Iron or steel flues should not be within a nine inch direct line of any combustible materials and where they pass through walls, ceilings and roofs they should be enclosed in metal sleeves at least twice the diameter of the metal flue and having

air spaces of at least two inches between the flue and the sleeve and one inch between the sleeve and the adjacent combustibles. OIL BURNERS The Installation of oilburning heaters must comply with the relevant rules of the Dangerous Goods Regulations 1958, and domestic installations must also comply with the Underwriters’ Rules. Because the fuel for these appliances is liquid it can greatly aggravate a fire. For instance, a fire that deitroyed a wooden building was discovered by a passing motorist. In spite of the delay in discovery and the lack

of water the fire brigade believed it could have saved the building were it not for the fuel oil that escaped from the 200-gallon tank in the basement and kept feeding the fire. Automatic fire valves are required on all oil burning heaters so that in the event of a fire around the heater the fuel supply will be automatically cut off either at the tank where the fuel line enters the building. Where there is a choice between gravity feed supplies and underground tanks with the oil being lifted by a suction pump, insurers prefer the latter, it being inherently safer. Because water is not a satisfactory extinguishing agent for flammable liquid fires the regulations and rules require a suitable extinguisher to be associated with every oil burner. KEROSENE HEATERS Portable kerosene heaters last year in New Zealand caused 374 fires, mostly through misuse and not observing the manufacturers’ recommendations. These heaters should not be refuelled or moved while they are alight. They should be placed in a position where they are not likely to be accidentally knocked over.

Some of these heaters when placed in a position exposed to draughts can flare up, therefore they should be placed in a sheltered position. ELECTRIC HEATERS The flexible cord to an electric radiator which ran under the rug at one - end of the living room was worn bare by the ordinary traffic over the rug. A short circuit in the extension cord ignited the rug while an elderly couple slept upstairs in a two-storey brick house. The occupants apparently awoke and tried to escape from the heavy smoke in the house. The body of the man was found on the livingroom floor at the end of the room, opposite the origin of the fire, and the woman was found in the bathroom—both had been asphxiated. Electric heaters last year caused 6397 fires. These universally popular and highly portable devices are quite safe provided they are treated with the respect that is due to a lightweight high energy output source. Flexible cords should not be placed under carpets or stretched out so that people accidentally tripping on them pull the heater over or around so that it faces combustible drapes.

Heaters should not be placed so that clothing or bedding can fall on to them. When not in use heaters should be unplugged so that there is no chance of them being accidentally turned on with another appliance. All radiant heaters should have adequate guards. GAS HEATERS Gas heaters also should be adequately guarded, large burners should be lit with a pilot jet rather than a match. All burners connected to a gas supply by flexible tubing must use approved metal armoured flexible tubing. Rubber and plas-

tic tubing is not allowed by insurers.

A few years ago, serious fire damage was caused by a small fire which involved a rubber tube that connected two one-and-a-quarter inch iron gas pipes. The fire

burnt through the rubber and the ensuing gas jet caused severe fire damage 20ft away from the original fire.

If you are in doubt over the safety of your heating appliances do not hesitate to

contact your Insurance company which, if it is a member of the Council of Fire and Accident Underwriters’ Association, has access to technical facilities well equipped to advise on such matters.