When you need to cool an event space, office, school, retail business, manufacturing floor or computer server room and there’s no built-in HVAC system, or the one that’s there can’t deliver the necessary Btu, it’s time for temporary cooling. Use the information below to help you choose the right type and size of portable air conditioner or other temporary air conditioner to rent.
Units are rated by tonnage and/or Btu. One ton can remove 12,000 British thermal units (Btu) in an hour. To convert an AC unit listed in tons to Btu, multiply by 12,000. A 5-ton unit delivers 60,000 Btu, for example.
When renting portable air conditioning units, consider the space you need to cool. To cool a space with standard 8-foot ceilings, follow this guide:
- A 1-ton AC unit (12,000 Btu) will cool roughly 400 square feet.
- A 1.17-ton AC unit (14,000 Btu) will cool roughly 600 square feet.
- A 1.5-ton AC unit (18,000 Btu) will cool roughly 1,000 square feet.
- A 2.5-ton AC unit (30,000 Btu) will cool roughly 1,500 square feet.
- A 5-ton AC unit (60,000 Btu) will cool roughly 2,000 square feet.
- A 10-ton AC unit (120,000 Btu) will cool roughly 4,000 square feet.
Choose a larger unit if the space has tall ceilings, multiple windows or limited insulation, if it will house multiple people, or if the outdoor environment is very warm or humid. Computers and servers require cooler temperatures, which means additional Btu.
If you’re looking for an outdoor air conditioner rental for an event in a tent, remember that tents have no insulation, so you’ll need more Btu than the square footage alone would imply.
A larger commercial or industrial air conditioning unit rental such as this 80-ton temporary air conditioner can deliver 960,000 Btu and cool a warehouse or emergency shelter.
Air-cooled units, which are the most common portable ACs, need venting, typically through an exhaust hose, to eliminate heat. The venting path will influence where the unit is placed. Most portable AC rental units come with a kit that includes an exhaust hose and hardware.
If you can’t vent the hot air out of the space, consider a water-cooled AC unit. These use water to cool down the air, so no venting is required, though you do need a water supply.
An air-cooled portable AC unit removes moisture from the air as part of the cooling process. That moisture needs to be drained. The simplest units have condensate tanks that are emptied manually. If the unit has a drain port, you can attach a drain hose and direct the water to a drainage point.
A fully self-evaporative unit is the most convenient option because it expels all of the condensed water through the exhaust hose. A partially self-evaporative AC can automatically send most of the condensed water back into the environment, but some condensate will need to be drained.
Portable AC units that are suitable for small spaces or spot cooling use standard 120-volt power outlets. Larger units require higher-voltage outlets that must be hardwired by an electrician. A 3-ton unit, for example, typically requires a 208-volt, single phase, 30-amp circuit. Alternatively, you could deploy two or three 1-ton units that use standard 120-volt outlets.
Some portable air conditioners do double duty as heaters and can be used through multiple seasons. They typically have an electric heater or a heat pump.
Electric heaters deliver better performance in colder climates. Heat pumps, which work by extracting ambient heat from outdoors, tend to be more energy efficient in more moderate environments, where they can move heat around instead of generating it.