Portable Heater Options for Winter: United Rentals

Feb. 11, 2021

Low winter temperatures can drop worker productivity on a construction site—even for crew members working within a building shell. Creating a comfortable working environment via temporary heating can help keep workers moving freely and projects on schedule. United Rentals has outlined a range of portable heater options that contractors can use to warm up cold crews and temper spaces.

One study showed that worker efficiency starts to drop slightly when temperatures sink below approximately 50 degrees Fahrenheit, according to United Rentals. Efficiency drops by about half when the mercury hits zero degrees.

Choosing the Right Temporary Heater

Ventilation, safety and space are three important considerations for contractors when choosing a temporary heat solution.

Make-Up Air Heaters. These heaters are ideal for any size space heating the air with relatively low fuel consumption. They pressurize the space, evenly distributing heat while maintaining fresh air changes. The heaters can be powered by natural gas or propane, and can be placed inside or outside so long as fresh air enters the unit. Heater options are based on BTUs with a typical range from 80k to 4.5M.

Indirect Fired Heaters. These heaters are similar to a home’s furnace, requiring exhaust ventilation to outside air. They are powered by diesel fuel, natural gas, or propane. The heaters provide 100 percent clean, dry air. There are no combustion by-products, moisture, or other impurities released into the air. The heaters don’t have an open flame so air entering the heater space never comes in direct contact with a flame.

Electric Heaters. These heaters should be used when absolutely no flame is permitted at the worksite, and when power is easily and readily available. Power requirements typically range from 120V to 480V. They need no ventilation and can be used when a building is mostly closed in. The heaters provide safe, clean, and combustion-free heat.


Direct Fired Heaters. These heaters provide a simple and economical solution. They are powered by natural gas or propane. The heaters should be used where there is plenty of ventilation, such as an office building with no windows installed. They have an exposed flame and should not be used in any area where there are combustible products.