Like many products where competition is steep, air conditioner manufacturers sometimes push features to gain market share. Consumers are sometimes left wondering just what’s worthwhile and what’s hype. We’ll try to sort through the mess.
First the basics
Before the features come into play, we ought to mention the primary reason for getting an air conditioner: cooling. None of the features listed will overcome a mismatch between cooling capacity and the area you need to keep comfortable.
Too large and the unit will cycle frequently and draw more energy. Too small and the unit won’t be able to handle the demand. A standard sizing chart appears on the Energy Star website1. Pay attention to the footnotes under the chart and you won’t go far wrong.
Price is certainly an obstacle for most of us. A good rule of thumb is to buy the highest quality system you can reasonably afford, and, unlike other appliances, pay attention to warranty information. If you purchase locally, consider buying an extended warranty – where the local business sends someone out. There is a clear advantage in a quick repair when a system has problems during a summer heat wave.
Customer comments and reviews are worth reading, and if you know someone involved in HVAC, get a second opinion before you buy. Brand names can be misleading, but it’s worthwhile to spend a few dollars more to deal with a reputable company.
Other basics often overlooked are the noise a unit produces and the cost to run it. Pay attention to the SEER rating2 when comparing air conditioners and any comments about noise. If you have a noisy ac, please check out our quietest window units page. –Dave
Most popular features
Many of these features are standard on mid-range units. They are easy for manufacturers to add and don’t bring the price up much3.
• Remote control – just like it sounds, you click a remote and the AC starts up. More advanced versions also let you control fan speed, temperature and other options remotely. This is particularly nice when the AC isn’t easy to get at (mounted high up or when someone is chair-bound).
• Variable fan speeds – helps to circulate cool air further
• Directional fan – allows cool air to be sent where it’s needed most
• Washable filter
• Clear digital display, easy to understand controls. In this case, it may be “less is more” – many consumers don’t want complicated functions and don’t use most of them.
• Timer – this may or may not be included in a basic package. The convenience of having the AC turn on an hour or so before you arrive home is well worth it. Timers can also be used to shut the unit down during the night when temperatures naturally cool down.
• Fresh air intake. This allows you to bring in outside air and is used extensively just before and just after the main cooling season. Often, outside temperatures drop before a house has a chance to “catch up” – bringing in fresh air acts like air conditioning any time the outside air is better than the inside air.
Auto restart – after power loss, this saves settings and restarts the unit. Very common, this feature helps in areas where there may be “brown outs” or blown fuses.
Sleep Mode – lowers temperature (and saves energy) without shutting unit off. Set to a pre-set time, usually an hour after bedtime.
DC compressor or inverter technology – by converting alternating house current to direct current, these units use less energy, run more quietly, and have a smoother start and running for the fan and compressor. Overall, inverter technology allows for quieter operation with less energy used in starting and stopping the moving parts.
Oscillating vents – great for larger rooms, these allow cool air to be sent in several directions, avoiding “hot spots.” Not really needed in smaller rooms.
Dehumidifying Mode – used in the spring or fall when humidity is high but temperature is not. Units with this feature remove moisture from the air and drain it outside.
Check filter light – indicates when air flow is low because of a clogged filter. Helps those who are not keen on regular maintenance.
Over the top
Some features may be of interest to consumers with specific needs or wants, but aren’t appealing to most of us. Generally, these features are only found in high end units where price is not an obstacle. Sometimes it seems as if they are added only to make a unit seem exclusive or unique.
Custom filtration – A general rule is that if you need quality air filtration, get an air purifier instead of relying on an air conditioner. However, some manufacturers combine top end filtration with their air conditioners. An example is Hitachi’s “Nano Titanium WASABI Air Purifying Filter.” The system is heavily marketed5 and includes actual wasabi in the filter to act as an anti-bacterial, anti-mold and anti-allergen.
Added scents – For commercial use, EcoScent offers cartridges that attach to HVAC systems6. Some home units also come with built-in “smell reducing” technology, usually based on a scented filter. They also offer odor masking in a similar fashion.
Wireless control – As all things move toward being Internet-enabled, we now have wireless air conditioners you can monitor, turn on and off, and pre-set with a mobile phone or other “smart” device. There are some applications – for instance, a cabin or second house you only visit occasionally or for commercial buildings with zone control. For most of us, this isn’t worth the price.
Wired wall thermostat – while there are applications where a separate wall thermostat may be practical, most don’t need this. A wall mounted thermostat is placed at a distance from the air conditioner so that it responds, not to the temperature where it is located, but the temperature where the thermostat is mounted instead7.