DennisBeaverFebruary 15, 2014 • By Dennis Beaver

When was the last time that you changed your furnace or A/C filters? Do you know why, in addition to controlling furnace and A/C run times and temperatures, filters have a huge impact on energy use and the life of your entire heating/cooling system?

“When you say huge impact, that is absolutely correct,” points out Jay Elepano, Minneapolis-based Senior Product Manager of Indoor Air Quality at Honeywell.

“Most people do not understand the importance of regularly changing your filter. What can result when not done is something you would never dream of,” he adds.

“Furnace and A/C filters serve two purposes,” Elepano observes:

• Protection of the unit itself from dust, dirt and debris that would shorten its life by years;

• Improving indoor air quality.

But when filters are not changed when necessary, you can expect:

• Higher energy bills;

• Less comfort in the home or office;

• Higher maintenance costs and greatly reduced life of the A/C coil, compressor, blower motor and a risk of carbon monoxide poisoning if the heat exchanger fails.

“Today’s filters are very good at capturing the most minute particles, and make a real difference, especially for allergy sufferers, but it is important to keep in mind that greater the filtration, shorter is the filter life — perhaps lasting only a month.

“When the filter is not changed when required, it becomes clogged, greatly reducing air flow, adding incredible amounts of stress on the entire system as you are forcing it to work much harder. It’s like trying to breathe through a straw.

“Over time this can lead to a breakdown of the system, and nationwide, clogged filters are responsible for a very high percentage of service calls.  But there are warning signs, such as your house not getting warm or cold enough, and energy bills which seem way too high. So, if you see any of these things, first check your filter. Change it, and hope there is no damage,” Elepano stressed.

Selma reader “Terry” would learn these expensive lessons a month after moving out of the house he and his wife were renting, “out in the country, near farms, ranches and orchards where it was very dusty,” he wrote.

“We were idiots, I admit. The landlord gave us a stack of filters for the furnace and A/C the day we moved in [and] told me to change them every month, but we completely forgot. Our utility bills were sky-high, but we never thought the reason could be that the filters were clogged. We just forgot, no excuses.”

“And then, the day before we moved out, the whole system just quit. I found out later that the clogged filters required over $2,000 in repair costs, and the landlord withheld $500 from our security deposit. Don’t you think she should have had a service company take care of changing the filters?  If I sue for my security deposit, who will win?  Do you have any advice?”

We phoned Terry. “Sure, we’ve got advice for you. Man up, accept responsibility, apologize and recognize that the landlord gave you a real break. You said ‘no excuses,’ remember?”  He agreed.

“Filters are rated on their ability to capture,” Elepano explains, “beginning with the largest particles such as dust and pollen, and down [to] the much smaller, such as bacteria, smog, smoke, mold spores. This is called a MERV rating, and stands for  Minimum Efficiency Reporting Value, and goes from 1 to 20, with 20 being the most filtration in a media (paper-type) format.

“As all filters restrict air flow to some extent, it can be a costly mistake to choose one with a  higher MERV rating than you need, for if you do not replace it often enough, over time, you will harm your system, driving up energy bills in the process.

“In selecting a filter, if the MERV number is not disclosed, then a good rule of thumb is the higher the number on the package, the more filtration. In general, for home or a small office, an equivalent of 8 – 12 would be appropriate.”

“The key to energy efficiency and prolonging the life of your system regardless of any MERV number your select is in replacing the filter in a timely manner,” Elepano underscores.

And, if you want even more filtration and cleaner air?  That’s where an air purifier might help, but there are scams galore and claims that would even make Bernard Madoff smile. In a future report we’ll tell ways of improving air quality at home without breaking the bank.

Dennis Beaver practices law in Bakersfield and enjoys hearing from his readers. Contact Dennis Beaver.