Whether for employee comfort, preventing frozen water pipes, or maintaining temperatures necessary for materials to set (for example adhesives), the cold weather season is a period when temporary heating systems on building sites are in high demand. If temporary heaters aren’t operated correctly, they can pose a substantial threat of fire into a job, and of course possible harm to employees.

Every year, construction site fires occur due to improper selection, setup, management, and use of temporary heaters. Construction fires may lead to significant, or total loss. Fire risks grow as well when temporary heaters, even those properly selected and installed, are left operating continuously or left unattended.

Given that the hazards temporary heaters can present, it is very important to select the ideal heater, in addition, to include their use and precautions inside your site-specific security plan to help ensure heaters are utilized safely.

Choosing the Safest Type and Best Practices for Using Temporary Heating

The permanent heating system, after installation and operational with all safety controls in place and operational, is your best source of heat during construction. If this isn’t an option, the next temporary heating devices can be found:

Indirect Fired

Indirect-fired heaters are commonly fueled by diesel, propane, or natural gas. The fire is contained in a burn chamber, where cool air passes over and about a heat exchanger and warm air is ducted into the building. The higher price and lower efficiency of these heaters are offset by the lower risks associated with general use, in addition to the decreased possibility of introducing carbon dioxide into enclosed buildings. You can also get an indirect heater on rental at the best price.

Tips for using indirect fired heaters safely include, but are not limited to:

  • Units must be located on a steady floor away from the building.
  • For gas-fired units, all fuel line piping should be flexible, American Gas Association (AGA) rated, and secured against physical harm.
  • Fuel tanks must be secured and secured with bollards or jersey barricades.
  • Flue stacks should be located away from combustibles and located to prevent fumes from entering the structure/building.
  • Units, including all hoses and fuel tanks, must be inspected and maintained regularly by a qualified vendor/service firm through a written agreement.

Direct Fired

Direct fired heaters, frequently known as “salamanders” or “torpedoes,” convert 100 percent of their fuel being used into heating. They have relatively low operating expenses, are easy to transport and locate, and are a highly effective heat source. The inherent hazard is the device gives a direct flame, and that, if too close to combustibles, can lead to a fire. It is generally not advised to utilize a direct-fired heater inside a wood frame structure. Due in part to maneuverability, these smaller units may also be more prone to tipping over. There’s also an increased potential for harmful levels of carbon monoxide within the building that can create a serious health hazard for workers.

Tips for using direct-fired heaters safely include, but aren’t limited to:

  • Place heaters on a non-combustible surface that extends four feet in front of the unit, unless approved otherwise by the manufacturer.
  • Be sure units are automatically secured to prevent movement.
  • Ensure digital flame sensors or pilot safety valves are in place.
  • Verify the unit is shut off and has cooled down before refueling. Never refuel inside or within 50 feet of the construction.
  • Maintain appropriate safety clearances on all sides from combustible materials.
  • Carbon monoxide detection, alerts, and make-up air systems should be used.


Portable electric heaters may meet the needs for temporarily heating smaller areas. These heaters use a filament or ceramic disk to make heat, and a fan disperses the warm air. Advantages include a reduced chance of health and safety exposures to workers, and disadvantages include a need for electrical power, and possibly the need for multiple heating units. You can also get a salamander heater on rental to feel hot on cooler days.

Strategies for using electric heaters safely include, but aren’t restricted to:

  • Units should only be utilized in a dry environment.
  • Ensure the electrical circuit is rated for the size of the unit.
  • Use ground fault protection for employee security.
  • Protect electric heaters from potential tip-over.
  • Find heaters away from combustible materials.

All temporary heaters must be UL, CSA, or ETL listed and supplied with automatic high temperature, tip and security shut down capabilities. As part of a general contractor’s approach to managing subcontractors, prior approval ought to have to permit heaters on site. Also, management must ensure that portable heaters are shut off and secured in the off position when left unattended. If it is necessary to allow a heater on, like during off-peak hours, security or other personnel should perform frequent inspections. It is also recommended that the local fire department be informed when any sort of temporary heating is being operated after work hours.

Shane McCourt

Shane McCourt

<p class="break-words white-space-pre-wrap mb5 t-14 t-black--light t-normal">Preferred Climate Solutions is owned and operated by HVAC veterans. We have over 17 years experience with portable heating and cooling systems, plus a lifetime of experience with Texas’ challenging climate. We provide an array of portable cooling and heating rental solutions 24/7. We have locations in Houston, Dallas/Ft Worth & Austin Texas.</p>

Leave a Reply