Heating
There are many types of heaters that can be used on a construction site. When selecting one, consider the size of the enclosure, the type of work being performed, and what type of fuel source is required. One heater may work well on one site, but it may not be suitable for another.
Electric heaters
Electric heaters are sufficient for smaller areas between 12 and 42 m2 (130 to 450 sf) with heating capacities of 5000 to 18,000 British thermal units (Btus) per hour. Smaller electric heaters can be plugged into a regular 120-volt receptacle, while some larger units will require a 240-volt receptacle. When using the latter, a licensed electrician may be required to connect it to a power source.
Forced air heaters
Forced air heaters fuelled by diesel, propane, or natural gas are ideal for medium- to large-tented areas. These heaters are equipped with a fan that sits behind an ignited burner which expels the hot air. Forced air heaters can warm an area between 88 and 929 m2 (950 and 10,000 sf) with heating capacities of 30,000 to 400,000 Btus per hour.
These heaters are primarily used in situations where workers are not present in the area for extended periods, as they exhaust directly into the tented area and produce significant amounts of carbon monoxide, which can be deadly to workers.
Indirect air heaters
Indirect-fired air heaters also use diesel, propane, or natural gas and are ideal for the largest tented structures. These heaters operate in similar fashion to a traditional furnace to produce clean, dry heat without the use of a flame. Exhaust air is expelled through a chimney, while heated air is returned through a flexible hose to the tented area. Indirect-fired air heaters can have heating capacities in excess of 900,000 Btus per hour.
Extreme caution should be taken when using any type of heating source on a construction site. Common hazards may include fire and explosions, asphyxiation, carbon monoxide, and burns. The location of the heaters should remain free of site materials and equipment. Proper ventilation and airflow should be maintained to any tented area where heating is present.
Workers who handle or connect propane-fuelled heaters must have a Record of Training (ROT) certificate which must be renewed every three years. There are legal requirements for the approval of equipment, the use of gas-fired equipment, and the storage and transportation of gas cylinders. The rules and regulations can be found in the Occupational Health and Safety Act, Transportation of Dangerous Goods Act, Technical Standards and Safety Act, which are overseen by the Technical Standards and Safety Authority (TSSA).
Courses are available to provide workers with the necessary training to safely connect, activate, and disconnect propane-powered equipment, as well as the safe handling, storing, and transportation of dangerous goods.
