Rosie on the House: Filter replacement maintains proper air flow

Bowed air filter.

If the air doesn't seem to move throughout your house, the problem could stem from restricted airflow. Not only will restricted airflow make the indoor climate uncomfortable, it can wreak havoc on your finances.

It is recommended that air filters should be replaced once a month.

Warped, bent, or howling coming through the grill when the A/C or heat is running indicated there may be not enough return air grills in the home. This can put additional strain on the HVAC system resulting in mechanical failures. Dust, pet hair, and particles can slip past the filter around the edges because of the high volume of air being forced through an opening that is too small, thus defeating the filter’s purpose.

There are two types of air filters; standard and media. Standard filters work to keep your system and its ductwork clean, but they don’t really improve indoor air quality. The most common filters are 1-inch in thickness and the number one cause of preventable mechanical failures is the restriction of airflow.

The media filter rests between the main return duct and the blower cabinet and will improve dust and particle removal up to seven times that of a standard filter. However, upgrading to a pleated media filter will remove everything from dust to many airborne viruses from the filtered air. Choose a filter that matches your blower’s capacity. For optimal efficiency and filtration, replace disposable filters at least once a month. If you have washable filters, clean them once a month.

Steps to replacing an air filter

Filters are often in ceilings or walls along the path of the ductwork that returns air to the air conditioning unit. Look for a removable metal cover in the ceiling, or low on a wall.

Rosie on the House: Filter replacement maintains proper air flow

Installing a new air filter.

• Open the metal cover to expose the filter.

• Remove the old filter and measure it.

• Buy a replacement filter the same size as the old one (as long as the old one fit). A good filter should run around $4.

• There will be an arrow on the side of the filter telling you which way the airflow is supposed to go through the filter. Install the new filter according to that airflow arrow.

• Reinstall the metal cover.

• Remove dust bunnies from the vent with a vacuum or slightly damp cloth.

• Dispose of the old filter.

• Repeat the process every month even if the filter's instructions say you can wait two or three months before changing it. Our dusty Arizona air makes filters extra-dirty, so they need to be changed more often than in other states.

For a window or wall mount air conditioner

The filter is located inside the unit.

• Turn off the air conditioner.

• Take the cover off of the front of the air conditioner; it may pop it off, or you may need to unscrew it. The filter is behind it.

• Remove the filter. You might be able to push it out, but some models are screwed in.

• Most window and wall mount A/C filters are reusable, so instead of replacing the filter, you will clean it. Shake or vacuum the dust off and rinse with soapy water.

• After the filter is completely dry, place it back into the unit.

• Replace the front cover.

• Wipe down the front of the unit.

Consequences of skipping regular replacement

Regardless of the rate of airflow, conditioned air around the coils is just heating or cooling the same air and not pushing it through the ductwork. By the time it reaches each room, it will not be the temperature you intended it to be. Plus, the longer the dust particles remain in the air, the more likely they will build up inside the unit, blocking airflow and possibly causing costly damage.

Rosie on the House: Filter replacement maintains proper air flow

Clean air filter vs. dirty air filter.

If you notice some rooms are warmer while others are cooler, that is because the air travels different distances to each room. Without adequate airflow, rooms further away may be hot in the summer and cold in the winter, while other areas get the majority of the airflow.

Air also becomes stagnate when it doesn’t move. Odors, dust, moisture, and other particles fall on to surfaces and into the carpet. No amount of air fresher will permanently remove it.

Spend the four bucks a month and replace your filter. Not only will you save money, but you will also physically feel more comfortable.

For more do-it-yourself tips, go to rosieonthehouse.com. An Arizona home building and remodeling industry expert for 35 years, Rosie Romero is the host of the Rosie on the House radio program from 8 to 11 a.m. Saturdays on KTAR-FM (92.3) in Phoenix; KGVY 1080AM 100.7FM; 10 to 11 a.m. on KNST-AM (790) in Tucson.