Filtering the Truth on High-Efficiency Furnace Filters
First and foremost, I want to be clear about the term “high-efficiency” when used to describe furnace filters. This term has no relationship to energy savings, but rather the filter’s ability to catch smaller air particles. Ironically, this enhanced filtering process actually has a negative impact on your heating or cooling system’s overall performance.
Over the years, we have handled many service calls that were the result of homeowners doing what they thought was a good thing by installing a pricey high-efficiency filter. The next day their system failed because the new filter restricted so much air to the unit that it shut down. Our solution? Replace it with a cheaper filter.
Truth be told, most systems do not need the expensive filters. It is better to buy a case of cheap filters and change them more frequently. While this may take a bit more effort, keep in mind the importance of maintaining adequate air flow into your heating and cooling equipment. Restricted air will make the compressor on your heat pump or A-C unit run inefficiently and can double your operational costs as well as shorten the life of the unit.
So what if you or a family member is asthmatic and requires really clean air?
Please note that the filters I have referred to in this article so far are the standard filters that are typically one-inch thick. If your home requires super clean air you need to seek out other alternatives, such as electronic filters or thick media types which can range from four to six inches thick. Because they have more filter surface area, you can use a better quality filter that will catch more particulates. Also, their thickness allows four times the amount of filter space for air to pass through, which is key to operational efficiency.
Another important factor is keeping the filter clean. While the manufacture may say that four-inch filters are good for a year, we have seen homes with large families, pets and old carpets that need to change the filter every two months. It all depends on the indoor environment.
My advice is to check your filters regularly. As soon as you see a layer of gray dust you should replace them. The energy waste from not replacing a filter is far greater than the cost of buying a new one.
If you have a question about filters or other heating/cooling issues, you can comment directly to this post or contact me with your questions.