Home Air Filters

Filters 101: What you need to know

• Who installs the air filters? You! It takes two minutes to dispose of an existing filter and properly install a new one. The trick is having the right size at the ready. Set a reminder on your calendar to switch out your air filters, or sign up for our subscription service. With us, you can buy one multi-pack that lasts all year, or subscribe to receive filters regularly. We will email you timely reminders when they need to be changed throughout the year.
• Why do I need air filters? Air filters absorb dirt, dander, dust, germs, and pollen from the air before they reach your heating/ventilation/air-conditioning (HVAC) system. Disposable filters are composed of fiberglass or pleated cotton/polyester in a cardboard frame, occasionally reinforced with metal wire or supports. Quite simply, they are an inexpensive way to help keep clean air circulating through your home, but only when properly fitted and changed regularly.
• What is a MERV rating? MERV stands for “Minimum Efficiency Reporting Value” or the effectiveness of the air filter. The higher the MERV rating, the more efficient the filter is at keeping out dust particles and other contaminants.
• When should my filters be replaced? Fiberglass and cardboard filters are the least expensive home air filter option. They filter out large particles, such as dust and insects, but are designed to last no more than 30 days. Pleated air filters are better designed to filter dust mites, pet dander, and germs and last up to 90 days. Homes with smokers, multiple pets, poor ventilation, or high dust or pollen content may require changing filters more often. Permanent air filters have steel frames and woven polypropylene centers. They must be removed, washed with a shower or hose, and replaced every month.
• Why do filters need to be replaced? Routinely replacing or cleaning air filters can lower your air conditioner’s energy consumption by 5-15%, according to the U.S. Department of Energy. Heating and cooling account for about 48% of the energy used in a typical U.S. home. If your unit has to work harder to pull in clean air, it requires more energy, and you’ll notice the difference in two areas – the accumulation of dust and debris on your home air filter and the increase in cost on your power bill. You may also notice the expense of HVAC repairs. Dirty filters reduce airflow, causing fan motors to work overtime and often burn out. In summer, clogged filters can allow dirt to cling to evaporator coils until they freeze. In winter, dirty filters can cause heat exchangers to crack, requiring immediate replacement due to potential fire, system failure, and the risk of carbon monoxide poisoning.
  
  Replacing filters is a healthy way to keep your home clean and to filter germs, dirt, and pollution from the inside air you breathe. If people with allergies or asthma live in your home, it’s especially important to regularly replace a quality air filter. Studies show regular HVAC maintenance and high efficiency particulate air (HEPA) home air filters are especially effective at reducing indoor airborne allergens, such as pet hair.
• Where do I find my filter? Try looking near your thermostat for the large metal grate that covers your home air filter. Note that some homes have multiple air filters, and they may be placed in the walls, ceiling, floor, or attic. Grates can be unscrewed or gently lowered to replace the air filters inside. If your current filter fits well, replace it with one the same size. Measurements are rounded up to the nearest nominal size, such as 16 x 20 x 1, and printed L x W x D on the frame. (If your filter has two measurements printed, go with the rounded-up nominal size when shopping for replacements).
• How do I replace my filters? Turn off the heat or air conditioning using your home’s thermostat. Remove or lower the metal register, then take out the existing filter from the vent and dispose of it responsibly. Insert the new filter, making sure it fits snugly and the printed arrows face in toward the air handler. Replace the register and restore your thermostat settings. Repeat the process for all the filters in your home. If your filter does not fit well, measure the length and width of the vent inside the metal grate, round up, and you’ll have the nominal size you need to purchase.
• How do I know what size I need? The correct size filter for your air conditioning and heating system is very important for proper operation. A filter that is undersized (or dirty) can restrict the flow of air through your system and affect the performance and may lead to higher energy cost. Most filters have the size printed on the frame for your reference
  If your unit doesn’t have a filter currently in the system, you’ll need to measure to get the correct size. A general guide to the minimum filter area in square inches (width x height of the filter) is below based on the system capacity (size in tons). The size of your HVAC unit can be found on your outdoor unit's data plate. If your system has two or more filters, this would also represent the minimum combined area of all filters.
  Filter Sizing Guide

• What if the filter in my system lists two sizes? You may notice two sizes printed on your filter. The “nominal” size is the rounded number used by most manufacturers. The “actual” size is the true measurement of the filter. Use the “nominal” size measurement when ordering.