Your Questions About Air Conditioning, Answered

Humming air conditioners are the soundtrack to summer season within the U.S., given that nearly 90% of households use them for cooling. Although air-con is all over the place, nonetheless, many individuals nonetheless have questions on precisely the way it works, find out how to use it greatest, and the way it impacts air high quality, human well being, and the atmosphere. TIME spoke to specialists to get solutions.

How does air-con work?

In probably the most fundamental phrases, “an air conditioner absorbs warmth from the constructing and dumps it to the surface,” explains Jeffrey Siegel, a professor of civil engineering on the College of Toronto who researches air flow and indoor air high quality. Extra particularly, a compressor strikes liquid refrigerant into an indoor coil, the place it evaporates and pulls warmth from the encompassing air. The gaseous refrigerant then flows to the system’s outside coil, transferring warmth out of your property. The gasoline condenses again right into a liquid within the system’s outside coil, and the method begins once more.

Central air-conditioning programs, window models, and mini-splits (which normally sit excessive on the wall) work in conceptually the identical method, however there are variations in how they’re put in and precisely how they switch warmth. Functionally, the largest distinction for customers is that central programs cool a complete dwelling, whereas window models and mini-splits are designed to work in just one room.

How do air conditioners have an effect on air high quality?

It is dependent upon what sort of system you could have. Window models and mini-splits sometimes don’t have high-quality filters, so that they don’t do a lot for air high quality past temperature regulation, Siegel says. Central air-conditioning programs, nonetheless, can provide invaluable filtration, catching particulate matter like mud, pet dander, mould, and smog. 

The upper a filter’s minimal effectivity reporting worth, or MERV, the extra it could lure. Excessive-MERV filters may even assist take away viruses from indoor air, in accordance with the U.S. Environmental Safety Company, however not successfully sufficient to depend on your AC system alone for illness prevention. You probably have central AC, ensure that to run the fan for no less than 20 minutes an hour, as air solely passes via the filter when the fan is actively operating, Siegel says.

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The tradeoff is that rooms which might be sealed for cooling don’t get a lot, if any, air flow from recent air. “Dilution with outside air helps eliminate a number of stuff,” Siegel says, so it’s a good suggestion to close off your AC and open the home windows for no less than a piece of day-after-day, so long as outside circumstances permit. “Sick constructing syndrome,” which causes folks to really feel unwell after they spend numerous time indoors, is considered linked to insufficient air flow.

Do you actually need to vary your air conditioner’s filter?

In a phrase: sure. A grimy filter gained’t do your well being any favors, significantly if it’s harboring micro organism or different disease- or allergy-causing grime.

However the well being of your cooling system could also be an much more urgent concern. “For those who let that gunk construct up in your filter, you’ll be able to destroy your system,” says Francis Dietz, vice chairman of public affairs on the Air-Conditioning, Heating, and Refrigeration Institute, a producer’s commerce affiliation. “The air can now not get via that filter, so it backs up into the system and it freezes up.” (In need of a complete system meltdown, Siegel says, you might merely discover that it’s not working in addition to typical.)

Precisely how usually you could change or clear your filter is dependent upon the producer’s directions and the way closely you employ your system, Siegel says, however roughly each three months is an efficient ballpark estimate.

Is it okay to run air-con on a regular basis?

From a mechanical perspective, a correctly maintained system ought to be fantastic to run 24/7, Dietz says. However an previous or uncared for unit might die beneath the pressure of fixed use—therefore why many individuals’s programs “conk out” throughout a heatwave, he says. Save your self the emergency restore prices and schedule a routine service appointment each spring, Dietz suggests. And remember that the common central air-conditioning system has a lifespan of about 15 years. Particularly if yours is getting near that time, Dietz says, it’s value having it inspected earlier than an issue arises.

Even when it’s technically potential, although, consistently operating your AC does have downsides, says Stan Cox, writer of Shedding Our Cool: Uncomfortable Truths About Our Air-Conditioned World. Your utility payments will soar, as will your power utilization. Air conditioners use about 6% of all electrical energy produced within the U.S. and account for the discharge of 117 million metric tons of carbon dioxide into the ambiance annually, in accordance with the U.S. Division of Vitality. Which means the programs we depend on for cooling are actively contributing to our warming planet.

Research additionally counsel that the human physique can construct tolerance to warmth via publicity—so fully avoiding heat by shutting your self in a refrigerated room on the first signal of spring thaw means you might be further depressing come August. “Our consolation vary will not be fastened,” Cox says. “It strikes up and down relying on the temperatures you’re uncovered to.”

Why does air-con make you’re feeling sick?

Some folks expertise respiratory signs, like a runny nostril or scratchy throat, after sleeping in a closely air-conditioned room. Which may be the results of a unclean system, Siegel says, or it may very well be resulting from a scarcity of air flow. Air con additionally removes humidity from the air, Cox says, and that dryness can contribute to signs like sore throats and complications.

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More often than not, these signs aren’t trigger for nice concern. However contaminated cooling programs have been linked to critical diseases like Legionnaires’ illness and may trigger an allergic response that results in lung irritation.

Which kind of air conditioner is best?

Usually, central AC is best in case you’re attempting to chill a complete home as a result of it has “economies of scale,” Dietz says. It’s designed to succeed in each nook and cranny of your own home utilizing one comparatively compact system, whereas you’d want numerous window models or mini-splits in case you cooled every room individually.

However, Cox says, it’s value contemplating how a lot of your property really must be cooled. You could possibly, for instance, place window models or mini-splits in your bedrooms for in a single day use and easily use followers in dwelling areas. That might not be a viable possibility relying on your loved ones’s schedule, dwelling area, and native local weather, however such a system “makes use of lots much less electrical energy than holding the entire home cooled off constantly,” Cox says.

Is there a minimal or most temperature at which it’s best to use AC?

Plenty of folks have guidelines about after they’ll activate their AC for the primary time—not earlier than June 1, say, or not earlier than the temperatures high 80°F—however these are simply private preferences, Dietz says. There’s no motive you’ll be able to’t use your air conditioner on a gentle day, apart from issues about power utilization.

For those who’re on the fence about whether or not it’s scorching sufficient to show in your AC, nonetheless, Cox recommends attempting a fan first. You could be shocked by how effectively followers work, both on their very own or as a method of lowering your air-conditioning utilization. Analysis has even proven that folks don’t really feel any distinction between cranked-up AC versus a fan paired with AC on a decrease setting.

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“If the ambient air is cooler than your physique, the fan is flooding your physique with air that’s decrease than your pores and skin temperature and blowing away the nice and cozy air that accumulates across the floor of your pores and skin,” Cox explains. Circulating the air round you additionally helps sweat evaporate out of your pores and skin, a key a part of the cooling course of.

That stated, followers don’t work on scorching-hot days, when the air round you is hotter than your physique temperature. In these instances, it’s best to resort to air-con, both in your house or at a group cooling heart.

You could discover that even your AC isn’t as efficient as typical on a particularly scorching day, as a result of it has to work tougher to switch warmth from your property’s inside to the outside air, Siegel says. Nonetheless, so long as your unit is correctly maintained, it ought to work effectively sufficient to maintain you cool and protected on even the most popular of summer season days.