Energy Efficiency|General

How do you know how effectively an HVAC air filter will safeguard your indoor air quality? The MERV rating was designed to provide a quick basis of comparison between different filter types. Expressed as a number between 1 and 16, MERV actually stands for Minimum Efficiency Reporting Value. The higher the MERV rating for a filter, the more efficiently the filter performs.

As long as your air conditioner or furnace is running, it’s pushing air through the HVAC air filter. In a typical day, all the air inside your home circulates through the ductwork and filter multiple times. That’s why the quality and efficiency of your air filter matters. Here’s how the various MERV filter ranges stack up by comparison:

MERV 1–4

Usually, the least expensive fiberglass panel filters that perform the least efficiently. Typically, these filters remove only the largest particles of dust — the stuff you can actually see — from the air. Smaller invisible particulates, which make up the majority of indoor pollution, escape filtration. Most HVAC professionals recommend immediately replacing them with a higher rated filter.

MERV 5–8

The most appropriate filter choice for most households, this range is dominated by quality pleated cotton or polyester filters. They will remove airborne particulates down to a size of 3 microns. This comprises all lint and dust, pollen, dust mites, and mold spores. Filters in this range offer the best balance between filtration efficiency with minimum airflow restriction.

MERV 9–12

If some family members have a particularly high sensitivity to certain airborne allergens, these filters provide an extra level of protection. They will remove 80 percent of airborne particulates down to a size of 1 micron.

MERV 13–16

This high-efficiency range is generally limited to hospitals, clinics and other commercial systems where HVAC systems incorporate high-speed blowers and high-volume airflow. For typical residential systems, however, these filters are too dense and excessively restrict airflow, causing poor cooling/heating performance and reducing energy efficiency.

Using an energy evaluation to determine how energy efficient your home is can help curb your monthly utility bills, and who doesn’t want that with the continued rise in energy costs.

Did you know that you can find out how energy efficient your home is by comparing your home’s yearly energy use against other homes around the country? Using the Energy Star program’s easy, online energy evaluation tool to plug in the total yearly kilowatts of energy and dollars spent, plus your home’s square footage and the type of fuel your home uses, produces a score that can help determine the kinds of improvements needed to make your home as energy efficient and comfortable year-round as possible. The suggested improvements can lead to long-term savings on utility bills and help save our natural resources too.

To get started on your home’s energy evaluation, collect:

• One year’s worth of utility bills or a 12-month summary statement
• Your home’s total square footage of all interior spaces, including basement, attic, garage, extra room over garage, etc.
• A list of all types of energy your home uses: electric, natural gas, fuel oil, propane, wood, coal or kerosene

If you don’t know your home’s square footage, the online energy evaluation tool has a link that will help you determine this. You can also call your local utility company to see if they provide free or discounted home energy audits.

Once you have your score your next move is to decide if you want to make the improvements yourself or hire a qualified HVAC professional to implement the suggestions. The Home Energy Advisor is a good guide for DIYers, but because California has such strict building and environmental codes, professional help might be a smarter solution.