Everyone knows that air conditioning keeps your home cool during the summer, but it does much more than that! Willis Carrier, the “father of air conditioning”, defined it as:
- Maintaining suitable humidity in all parts of a building
- Freeing the air from excessive humidity during certain seasons
- Supplying a constant and adequate supply of ventilation
- Efficiently removing from the air micro-organisms, dust, soot, and other foreign bodies
- Efficiently cooling room air during certain seasons
- Heating or helping heat the rooms in winter
In addition, he said that an air conditioner should not be cost-prohibitive, either in purchase or maintenance. Here are the answers to 10 more air conditioner questions we get all the time!
How does an air conditioner work?
Air conditioners keep your home comfortable by moving heat from inside your home to outside. To do this, air is blown through your vents over a set of pipes called the evaporator coil. The evaporator coil is filled with refrigerant which absorbs heat from the air, cooling it down and blowing it back into your home. The refrigerant then cycles out of the evaporator coil into the condenser coil, located outside of the house, where it releases its heat before moving back into the evaporator coil. A pump, called a compressor, moves the refrigerant between the two coils and changes the pressure of the refrigerant so that all of the refrigerant evaporates or condenses in the appropriate coils.
The whole system is powered by the pump in the compressor, and when properly tuned-up, your air conditioner will provide about three times the cooling energy that the compressor uses. This odd fact happens because the changing of refrigerant from a liquid to a gas and back again lets the system move much more energy than the compressor uses.
What is a “ton” of cooling?
You may have heard air conditioners described as being a “2.5 ton system” or something similar. But the systems themselves don’t weigh that much, so what does that actually mean?
Way back in the day, before refrigeration cooling was invented, cooling was done using huge blocks of ice. When cooling machines came around, their capacity was rated based on the equivalent amount of ice melted in a day—hence the term “ton”.
These days, a ton of cooling is defined as 12,000 BTU/hr of cooling. BTU stands for “British Thermal Unit” and is a measure of heating energy (or cooling, as it were). Fun fact—the British don’t actually use British Thermal Units to measure their ACs!
What can go wrong with an air conditioner?
While furnaces tend to be pretty simple, air conditioners are very complex and rely on a wide variety of moving parts. First, they must be sized correctly to meet the correct “load,” or cooling requirements, of your home. Next, they must have the correct “charge,” or amount of refrigerant. Finally, they need to have the proper airflow across the evaporator coil. If any one of these things is thrown off, for any reason, it could cause your system to break down.
Your air conditioner can also run into problems if:
- You produce more heat indoors, either from having more people in the house, or from having several large appliances running at once.
- The refrigerant leaks out, which will lower the capacity of your system.
- Airflow across the coil is reduced for any reason, including blocked air filters or faulty blower fans.
What’s the point of AC filters?
AC filters do what their name implies—they filter particles, including dust, smoke, viruses, and bacteria, from the air to keep the system clean and to remove those particles from the air you and your family breathes. As the filter collects more and more over time, it gets more efficient at catching things, but also reduces airflow through your system. After a while (usually every month to three months), you’ll need to change the filter to prevent damage to your system.
Not changing your air filter can lead to issues with reduced airflow, which forces your AC to work much harder than normal. This causes major problems with efficiency and can even contribute to worse air quality problems! Improper airflow can also cause the evaporator coil to freeze, which can lead to big problems in your home.
Removing the filter completely would technically solve your low air flow problem, but trust us – you don’t want to do this! Everything your filter removed from the air would not only make your family sick and make the air in your home hard to breathe, but it would also build up on your coil and cause it to fail! For best results, remember to change your filter once a month to three months.
When you do buy a new filter, ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers) recommends getting one with a Minimum Efficiency Rating Value (MERV) between 6 and 8.
Do I need professional AC maintenance?
Certain AC maintenance tasks, such as changing air filters, are easy enough to do on your own. Others, including inspecting system coils and taking voltage readings, are best left to a professional.
When you’re getting ready to turn your system on at the beginning of the season, it helps to go outside and brush dirt and obstructions away from the compressor (the outdoor unit). You can also hose the system down to clean it off from the inside.
If your system isn’t producing as much cold air as usual, you may want to call for service—this could indicate a low refrigerant charge or airflow problems.
Should I inspect my ducts?
You may have never seen the ductwork in your home, but as it turns out, your ducts matter—a lot. Leaky ducts can drain 30% or more of the cold air your system is producing, even if your AC is running perfectly otherwise. Uninsulated ducts that pass through unconditioned areas like the garage or attic can bleed energy as well, also increasing your costs. In fact, you may be able to reclaim as much as a half-ton of cooling just by sealing your ducts!
How can I increase my system’s energy efficiency?
Sealing leaky ducts is probably the biggest thing you can do to improve your air conditioner’s efficiency. But that doesn’t mean it’s the only thing! Other ways to save energy while staying comfortable include:
- Replacing dirty air filters
- Keeping the right charge and airflow
- Keeping the coils clean
- Keeping the area around the outdoor unit free of blockages
- Buying high efficiency equipment
Can I ease the strain on my air conditioner?
A great way to help your air conditioner work more efficiently is to reduce the amount of work it actually has to do. You can remove heat from your home by improving insulation levels, shading windows and reducing air leakage, or replacing windows or your roof with high efficiency products.
But it can be even less complicated than that. Turn off all unused appliances, lights, and other equipment. Use bigger appliances, such as washers and dryers, at night when the cooling load is lower. Use exhaust fans to remove heat and humidity from kitchens and bathrooms.
What’s the point of ventilation?
Remember that your air conditioner does much more than cool your home—another one of its main responsibilities is to keep it well ventilated, meaning it brings fresh air in while moving stale air outside. ASHRAE recommends that your system be able to completely exchange the air in your home at least once every four hours, depending on the house design.
If your home isn’t ventilated properly, dust, allergens, bacteria, and other indoor air pollutants can lead to serious health and comfort problems. ASHRAE recommends one complete air exchange-where all the air in your home is replaced with air from outside-every four hours.
What can I do about all this humidity?
Fun fact: air conditioners weren’t invented to control temperature—they were originally created out of a need to control humidity! Lack of humidity control in hot, humid climates, like every summer in the DC Metro area,Poor humidity control can lead to moisture-related problems like mold growth, which can be hazardous to your health.
The good news is most well-installed and maintained air conditioners dehumidify in addition to cooling, though this isn’t their primary job. There are also things that you can do to help your system when it gets especially humid:
Keep your thermostat fan switched to AUTO – your thermostat;s fan switch has two settings: ON and AUTO.When set to ON, the fan will blow constantly whether the compressor is running or not. The problem with this, in addition to being very inefficient, is that moisture collected on the coil will not have time to drain away, and will instead be blown back through your house, leading to the aformentioned humidity problems.
Use exhaust fans when possible – you should have exhaust fans installed in both your kitchen and bathroom-use them! Cooking, showering, and washing clothes all produce a lot of moisture. The exhaust fans take up that moisture and move it out of your home.
Keep windows closed on especially humid days.
We hope these were helpful! Remember, if you need air conditioner services in Maryland or Washington, DC, call Michael Bonsby Heating & Air Conditioning today!