A cooling fan rental starts at about $20 to $45 a day for a 24 inch drum fan and reaches $50 to $110 for a portable axial ventilator with ducting. None of them lowers the temperature of the air; they move it, and moving air over skin is what makes a hot space bearable. That distinction decides which machine is worth booking.
A fan does not cool air, it cools people
Air leaving a fan is the same temperature as the air entering it, fractionally warmer for the motor work. What changes is how fast sweat evaporates off skin, which is why a fan aimed at a crew helps and a fan aimed at a room achieves nothing measurable. Point it at people, or at the opening you want air to leave by.
Drum fans, axials and the difference that matters
A drum fan is a wide slow blade in a tilting cradle, made to throw a broad wash of air across a bay. An axial ventilator is a narrow high pressure unit built to push or pull air along a flexible duct into a tank, a crawl space or a manhole. One makes a space pleasant; the other exchanges air where there is none.
Sizing by air changes rather than by fan count
For ventilation the question is the volume of the space and how often an hour you want it replaced. Take the cubic feet, multiply by the changes you want, divide by sixty, then hire a fan rated above that in cfm with the duct allowed for. Every ten feet of flexible duct and every bend costs airflow, so oversize it.
Power on a hot site is the real constraint
Single drum fans draw little enough to share a circuit, but six of them on one temporary distribution box will not start together. Larger axial units and anything three phase want their own feed. Where site power is already loaded, the same counter hires generators and distribution, and booking both at once saves a second trip.
Questions people ask about cooling fan rental
Will a fan help above 95 degrees?
Less than people expect, and in very hot dry air it can push heat onto skin faster than sweat carries it away. That is where the answer becomes a spot cooler or a portable air conditioner from the same counter, or shade and scheduled rest, rather than a bigger fan.
How many drum fans for a warehouse bay?
One 24 to 36 inch fan makes a working area comfortable rather than a whole building. For a bay, place fans to create a through draught from one open end to the other instead of dotting them about, and hire the smallest number that gets air moving in a line.
Can I run a fan in a tank or a pit?
Only a ducted ventilator, and only as part of the entry procedure for that space rather than as a substitute for one. A drum fan sat at the top of a manhole moves almost nothing at the bottom. Hire the axial unit with enough duct to reach the floor.