GUIDELINES FOR ROOM HEATERS
The University of Sydney recognises that in buildings where air conditioning systems are not installed, room heaters may be required for thermal comfort. Room heaters must be safe to use, taking into account the characteristics of the area to be heated and the activities conducted in the area. Heaters must be maintained and shall be removed from service if not in good working order. Heaters with open flames or exposed elements capable of igniting fires are considered unsafe and shall not be used. Existing heaters of these types shall be progressively replaced with safer types. Floor model bar radiators shall not be used in any situation. Heaters shall not be used in flammable atmospheres or near highly flammable materials where there is a likelihood of ignition.
The University has a commitment to energy efficiency. Considerations of energy efficiency and heating effectiveness shall be taken into account when selecting room heaters for a particular application. Room heaters shall not be used in air-conditioned areas during normal working hours when the air conditioning is functioning. The use of localised heating devices interferes with the effective operation of the air conditioning system.
Personal heaters shall not be brought into University workplaces from home or other sources. Personal heaters may be brought into University-owned residential accommodation, but only if tested and tagged for electrical safety at the owner’s cost prior to being placed into service.
The following guidelines provide information for the safe and effective heating of rooms in the University where air conditioning systems are not installed.
1. SAFETY FEATURES
The ideal room heater has no open flames or exposed heating elements. The exposed surfaces of the heater should be cool enough to touch without the risk of burns. A safe heater has at least one of a variety of safety cut-off switches in case of tipping over, air inlets or outlets or elements being accidentally covered, electrical faults developing, or overheating for any reason. In addition, heaters that draw a relatively small amount of current are less likely to cause overloading of electrical circuits.
2. HEATING EFFECTIVENESS AND ENERGY CONSIDERATIONS
Optimal heating effectiveness can be achieved through minimising heat loss, by keeping doors and windows closed and excluding draughts. Using rugs or mats on uncarpeted floors also helps. Heaters should be turned off when the room is not in use. Frequent switching on and off and frequent changes in the thermostat setting increase energy usage. Using the correct capacity heater for the room contributes to energy efficiency. The temperature range to be achieved with the heater should be in the range of 19-22C. Higher temperatures waste energy. Energy efficiency contributes to a sustainable campus.
The optimum heating solution for an area is a balance between good energy efficiency and heating that is effective for the characteristics of the particular area to be heated, taking into account the tasks carried out in the area and personal preferences of the occupants. Large open spaces and rooms with high ceilings require more powerful heaters than smaller areas or enclosed spaces. Some situations require rapid heating early in the morning and low level maintenance heating thereafter. Other situations may require only intermittent heating.
A number of factors should be considered in positioning the room heater. Heaters should be:
- orientated to provide optimal heating
- placed away from combustible material such as paper bins, desks, curtains, carpet (to prevent fire)
- situated out of human traffic areas (to prevent contact burns)
- situated so that cords or heaters do not pose trip hazards
- situated so that cords are not run under carpets or mats, as they can be unknowingly damaged through wear and tear.
Built-in heating facilities (connected to gas or oil pipe) must be regularly and frequently serviced to maintain correct working order. Those that are not maintained are not considered safe to use.
Portable heaters must be included in the electrical appliance testing and tagging program, and tested and tagged prior to use. Damaged heaters should be promptly removed from service and repaired by qualified technicians or replaced. Care should be taken to avoid damaging heater electrical cords.
Heaters that have an open flame or exposed heating element can be the source of ignition in a fire. These heaters, including small fan heaters, must not be left unattended whilst operating. Models that feature automatic cut-out upon tipping, overheating or other fault are preferred.
These guidelines cover the different types of room heaters available. Selection should be based on consideration of safety features, energy efficiency, heating effectiveness, the characteristics of the area to be heated, the types of tasks performed and the preferences of the occupants. For new or replacement room heaters, ceramic heaters and electric panel heaters are preferred. Oil filled column heaters may be suitable, but are less energy efficient than ceramic and panel heaters. Types that use an open flame or exposed heating element and are capable of igniting fires shall not be purchased.
1. CERAMIC HEATERS
Ceramic heaters, sometimes known as ceramic furnace heaters, are a modern type of room heater. Most models incorporate a fan, which can make them effective for larger spaces, areas with high ceilings and areas where draughts cannot readily be eliminated. The features of these heaters include:
- greater energy efficiency than many other types of electric heaters
- rapidly reach the temperature set point
- safety features such as thermostat, safety cut-off switches
- compact size
- some models incorporate a temperature sensor, which enables the heater to maintain a set temperature in the room.
- Low wattage panel heaters are suitable for use under a desk enclosed on three sides and act to warm the lower half of the body when seated at the desk. They are highly energy efficient. However, they are not capable of heating a whole room.
- Convection panel heaters can effectively heat small and medium rooms, depending on capacity. Some models are fan assisted, which increases the heating rate and is more effective for large areas or those with high ceilings. The heating panels are slim, and most models are easily moved. Adjustable settings to suit a variety of situations are usually available.
3. OIL FILLED COLUMN HEATERS
Oil filled column heaters can be effective and may be suitable for larger offices, provided there are no high ceilings or draughts. They can be slow to heat a room, as they rely on natural convection and radiation. The features of these units are:
- relatively energy inefficient and they tend to draw a lot of current, which can trip electrical circuits if too many other appliances are operating on the same circuit simultaneously
- safe (no naked flame or exposed coil), although the surface temperature can become quite hot
- temperature variation controls (adjustable to suit individual requirements and prevent overheating)
- movable on castor wheels.
4. GAS HEATERS
Gas heaters are very effective, can be highly energy efficient and are suitable where good positioning, maintenance and supervision exist. Models having low Oxides of Nitrogen (NOx) emissions should be selected. The capacity of the gas heater must be suitable for the size of the room to minimise the indoor air pollution risks. Rooms using gas heaters should be adequately ventilated. Gas heater features are:
- heating is derived by a naked flame igniting flammable gas, though the flame may be enclosed in the device and not visible
- the burning flame consumes oxygen in the room air, hence the need for adequate ventilation and the right size of heater
- restricted availability and location due to need for gas supply to the appliance.
Heating gas cylinders must not be housed inside a building and can only be installed by licensed gas fitters.
5. FAN HEATERS
Fan heaters using an exposed electric heating element capable of igniting fires shall be progressively replaced with safer models. Fan heaters are best suited to small rooms and intermittent use, with good supervision. Fan assisted heating can cause dryness in the air and stir up dust, so this type of heater is not suitable for people with dust allergies.
Features of fan heaters include:
- electrically powered, but energy inefficient compared to some other types of electric heaters
- exposed heating element used – capable of igniting fires unless fitted with a thermal overload cut-out switch and used under supervision
- temperature variation controls
- small enough to be portable.
6. BAR RADIATORS
Bar radiators are the least effective type of heating appliance. Models include the wall mounted (fixed) and the floor bar radiator (portable).
The floor model bar radiator has been a primary factor in numerous fires and contact burns. These heaters are considered unsafe and shall not be used. Those currently in service should be replaced by safer, more effective heating appliances.
Wall mounted bar radiators shall be situated away from combustible materials (eg. curtains, bookshelves) and secured soundly to the wall. Although these models are generally less hazardous than the floor model, they shall not be used in new room heating installations.
7. OFF-PEAK STORAGE HEATERS
This type of heater usually contains bricks that are heated overnight with low-cost off-peak electricity. During the day the heat is slowly released into the room. This type of heater is less flexible than other types. The main safety hazard is the high surface temperature of the bricks, which can cause contact burns. This type of heater shall not be used in new heating installations.
8. ROOM AIR CONDITIONERS
Locally installed room air conditioning units (“window rattlers”) may be of the reverse cycle type capable of heating as well as cooling. This type of room air conditioner should not need to be supplemented with a separate room heater. Some room air conditioners are of the cooling only type, and in that case a room heater may be used for heating. The two appliances shall not be used simultaneously.