Temporary air conditioning is hired by the ton, and the ton is what sets the price: a 1-ton spot cooler runs about $75 to $150 a day, while a 25-ton trailer-mounted unit is a monthly contract in the thousands. Get the sizing and the electrical supply right first, because the wrong plug is what sends a unit back on the truck.
Sizing is a heat load, not a room size
Square footage alone underestimates a server room, a kitchen or a tented work area badly, because people, machines and solar gain all add heat. A rough working figure for a mechanical space is one ton per 250 to 350 square feet, adjusted upward for equipment. Give the yard your equipment load and hours of use and let them size it.
Check the power before the tonnage
Small spot coolers run on a standard 115 V circuit. Anything from about 3 tons upward wants 208/230 V single phase, and larger units need three-phase or a generator alongside. This is the single most common reason a temporary cooling hire fails on arrival, and it is a two-minute question to the yard before booking.
What the rental term does to the rate
Emergency cooling is priced by the day and is the most expensive way to buy it. Weekly rates typically land near three to four times a day, and monthly contracts far below seven times a week. If you already know the chiller repair takes three weeks, book the month rather than extending a day hire twice.
Ducting, condensate and heat rejection
A portable unit moves heat, it does not destroy it, so the condenser air has to go somewhere: a ceiling plenum, a window kit or ducted outside. Condensate either drains to a floor point or fills a tank someone must empty. Ask which hoses, ducts and window kits are in the price and which are extra.
Questions people ask about temporary air conditioning rental
How many tons of temporary cooling do I need?
For general occupied space, one ton per 350 to 500 square feet is a starting point; for equipment rooms, one ton per 250 to 350. Any real answer comes from the heat load, so tell the yard what is in the room and how long it runs.
Can I plug a spot cooler into a normal outlet?
A 1-ton to 1.5-ton portable will run on a standard 115 V outlet, ideally a dedicated circuit. Larger units need 208/230 V or three-phase power. Sharing a circuit with other loads is what trips the breaker in the middle of the night.
Is a spot cooler the same as a portable air conditioner?
They overlap. Spot coolers are the industrial version: heavier casework, ducted condenser air, casters and hose kits, sized in tons rather than BTU. A household portable is easier to move and much smaller in capacity.