As Hartford’s trusted HVAC contractors, SM Mechanical Services emphasizes how important choosing the right filter can be in maintaining a functional, energy-efficient unit. HVAC systems are more than the units and ducts, and even small components like the indoor filters can be crucial to the overall performance and reliability of the installation.
Below, the SM Mechanical Services team discusses how to make the best choice of filter for your unit, including tips on function, type, ratings, and other considerations.
What Should an Air Filter Do?
The air filter is the first line of defense between the inlet into the inner air conditioning system and the pollution and debris outside it. The HVAC system circulates air throughout the building to prevent stagnation and regulate air at the desired temperature. Surprisingly, the HVAC unit could be in tip-top shape mechanically, but without the filters doing their simple job efficiently, the efforts of the entire system to cool and purify air will be useless.
Running a machine on dirty filters could easily lead to an early breakdown of an otherwise healthy HVAC unit. The filter works to trap debris particles and clean the air that enters the system so that it can maintain adequate airflow. Porous filters allow better airflow but filter less, whereas less porous materials take out more pollutants but are not as energy efficient.
Choosing the Right Filter Type Based on Cost and Safety
So, is it better to have finer filtration or better airflow? The middle ground is best. Organizations like the United States Environmental Protection Agency (EPA) use the minimum efficiency reporting value (MERV) rating to describe an air filter’s ability to deliver high-quality indoor air (the higher the rating, the smaller the airborne particles it will filter).
There are four primary filter types in homes and offices, including the following:
- Fiberglass filters: As the cheapest to replace, fiberglass filters also have the lowest MERV ratings (between 1 and 4). They are suitable for filtering large pollutants but do not provide great indoor air quality. They require monthly replacement.
- Electrostatic filters: The design of these delicate cotton or paper fibers traps smaller pollutants and comes in affordable standard sizes. Their average MERV rating is between 6 and 10, which captures finer pollutants and provides a good option for the average home.
- Pleated air filters: These highly rated filters cost slightly more, but pleated air filters’ folded layers of cotton effectively trap most smaller particles. The EPA strongly recommends any filter with an average MERV rating of 8 for residential properties, so pleated filters are both safer and more energy-efficient.
- HEPA filters: High-Efficiency Particulate Air (HEPA) filters are the most effective option, with MERV ratings between 9 and 16. The added benefit of ultraviolet light kills germs, and the filter can trap 95% of all particles, pollutants, and irritants. It is ideal for sterile medical environments but often incompatible with residential HVAC units (for cost reasons).
So, HEPA filtration is safe but less energy-efficient and equates to larger units at higher prices. The other option is a reusable air filter, which saves money upfront but requires consistent care or cleaning. Failing to maintain the reusable filter certainly negates any upfront savings and jeopardizes the system.
Three Ways to Select the Right Filter
Choosing the right filter depends on the building’s use and occupants. For example, a nearly empty warehouse may not need heavy filtration with adequate airflow. However, an average home needs exceptional air quality for health reasons.
Here are three considerations before selecting your next filter:
#1 Filter Size and Fit
Certain types of filters have the size written on the unit, making replacement easy. Without it, property owners need to measure the height and length of the vent opening and round up the size (never round down). Calculate carefully; a snug fit ensures proper filtration, but loose-fitting filters might allow air and debris to seep through.
#2 MERV Rating
A typical home should consider filters with an average MERV rating of 8 or higher, particularly where there are young children, pets, smokers, or anyone susceptible to illnesses. Purchasing filters that do not have MERV ratings listed puts the health of the home’s occupants at risk, but going for the highest-rated products is also incorrect. If the unit cannot handle decreased airflow (because of higher filtration), it could freeze or break down due to the strain.
If you are not sure, it is best to contact professionals like SM Mechanical Services to check the specifications.
#3 Cost and Frequency of Replacement
Are there benefits to purchasing cheaper filters? Yes, but only in the way of short-term costs. If the upfront cost is not a huge factor, rather look at materials and frequency of replacement. Paying slightly more could be more energy-efficient and cost-effective in the long run and be healthier for the building’s employees or residents.
Many filters require monthly replacement and run the middle ground on cost, but frequent replacements add up quickly. Quality pleated or HEPA filter materials require less frequent replacement, averaging once every three months. The cost for replacement is higher, but the other benefits tend to outweigh these costs.
Do Filter Ratings Matter?
Filters vary in terms of brand and quality, which is why the American Society of Heating, Refrigerating, and Air Conditioning Engineers created the MERV rating system. Ratings matter, as they remove the guesswork and make choosing the right filter a breeze. Conversely, filters that do not have a MERV rating on the packaging typically lack proper testing for filtering capabilities.
Filter Professionals—SM Mechanical Services
Any HVAC system is a valuable investment, and inadequate filters represent poor returns. Health risks and long-term maintenance or repair costs are well worth considering in selecting a filter, with the aim to find a balance between air quality and efficiency. If you would like to know more about where furnace air filters are located, why not contact the team at SM Mechanical Services?
The family-owned business provides affordable:
- plumbing,
- heating,
- ventilation and air conditioning services.
We also have 24-hour emergency services, same-day services, and flexible financing available.
Call SM Mechanical Services at 860-296-5100 today or contact@smmechanicalservices.com for more advice on choosing the right filter.