When choosing a window unit, the most important factor is the size of the room you wish to cool and the cooling power, measured in British thermal units, of the unit you choose.
Here’s a general guide for window air conditioners based on room size:
- 12′ x 12′ room: 5,000 BTU unit
- 16′ x 16′ room: 7,000 BTU unit
- 20′ x 20′ room: 10,000 BTU unit
- 24′ x 24′ room: 14,000 BTU unit
For a more accurate measurement, use the Air Conditioner Sizing Calculator at Consumer Reports.
In addition to size, make sure the AC unit you buy:
- Has an EER (Energy Efficiency Ratio) of 11 or higher
- Carries the EnergyStar label
- Has a low noise rating
- Provides good airflow
- Uses a permanent or reusable air filter
- Has various speed settings
Portable AC Units
A portable air conditioner is basically AC on wheels. It has an exhaust tube, which must be vented outside, to remove hot air from the room.
Portable AC systems don’t require permanent installation. In fact, they come with wheels so can move them from room to room. And most of them come with a window venting kit that allows you to prepare a window for the exhaust tube.
These systems accumulate moisture, and you’ll need to routinely drain them. This means emptying a reservoir on the unit or hooking up a drainage hose, if compatible with the unit.
Before purchasing a portable AC, consider its energy efficiency. Systems with dual hoses cool rooms faster than their single-hose counterparts.
You often see through-the-wall AC units in hotel rooms, but they’re also ideal for large open rooms, studio apartments or remodeled garages.
You can use through-the-wall units in rooms that aren’t connected to a central air conditioning system. They’re ideal for home additions and, really, wherever you want to add AC without running ductwork.
You can purchase these units with heating and cooling features, or just cooling features, and you must carefully choose where to install them.
You must install these units in exterior walls where there’s no plumbing or electrical wiring. In addition, you’ll need to install a sleeve or chassis that can support the weight of the air conditioner.
A mini-split ductless air conditioner is one type of through-the-wall system, but it’s not boxy and comes with a separate outdoor unit. Mini-split AC units are sleek, subtle and look good in any home.
Consider A Warranty
If you are worried about your air conditioning unit breaking down due to normal wear and tear, consider investing in a homeowner’s warranty.
A review team independent of Today’s Homeowner picked out the best homeowner warranty providers, though they also looked at smaller companies such as Fidelity National Home Warranty, Global Home USA Warranty, and A.B. May Home Warranty.