Portable covers two very different hires. One is a torpedo heater you lift with one hand, plug into a socket and feed from a propane cylinder, from about $40 a day. The other is a towable indirect fired unit with a diesel tank and ducting, nearer $150 a day and climbing, which arrives behind a truck.
The carryable end of the range
Forced air torpedo heaters burning propane or kerosene are the counter hire: light, cheap and available on the day. They burn inside the space they warm, so the exhaust goes where the heat goes and ventilation is not optional. Electric fan heaters are the clean alternative and are limited by the circuit you can find.
What a socket will actually run
A domestic circuit carries very little heat. Small electric units on a standard outlet warm one room; anything larger wants a dedicated higher voltage supply or a generator, plus the cable to reach it. Ask the yard for the amperage draw and compare it against the breaker you intend to use before the machine leaves.
Indirect fired, when the air has to stay clean
An indirect fired heater keeps combustion in a sealed chamber and flues the exhaust outdoors, blowing only warmed air down the duct. That is what you hire for occupied rooms, finishing trades, drying a slab, or anywhere fumes and moisture would spoil the work. It costs more, needs a fuel tank and takes longer to set up.
Fuel is the running cost
The day rate is the small number on a heater hire. Propane cylinders, kerosene or diesel are billed separately and a unit running around the clock in cold weather goes through them quickly. Ask for the burn rate at full output, then decide whether cylinders or a tank suits the length of the job.
Questions people ask about portable heater rental
Can I run a portable heater overnight?
Only a unit designed for it, with ventilation and a working carbon monoxide alarm, and never a direct fired burner in a sealed room. For overnight heat in an occupied or finished space, hire the indirect fired unit and flue it outside.
What size heater do I need?
Give the yard the room volume, the target temperature and how leaky the building is, and they will size it in BTU per hour. Oversizing wastes fuel and undersizing never catches up, and a poorly sealed shell matters more than floor area does.
Can I tow a heater with my own truck?
Towable units are trailer mounted and need a rated hitch, working lights and a vehicle plated for the loaded weight. Most people take delivery instead, because the yard charges each way but carries the compliance problem with it.
Do heaters need a generator?
Fuel fired heaters still need power for the fan and controls, though the draw is small. On a site with no supply a modest generator covers several units. Match its output to the total starting load rather than the running figure alone.