What is MERV? How do you choose the right MERV rating for your home or facility, and is it important?
You buy air filters whether you own a home or manage a business. You do this because indoor air quality is essential, and every HVAC system requires you to change the filters regularly. Your air quality and circulation efficiency depend on clear, clean, unclogged air filters as part of the system.
If you go to the store or search for air filters online, you’ll need to know your unit’s filter size and your desired MERV rating. The filter size you get is based on your unit specs. But what is MERV? How do you choose the right MERV rating for your home or facility, and is it important?
Called Thomas Hoffmann HVAC and received service very quickly. Regular winter maintenance was provided. They always do a great job.Really appreciate their service and would recommend to anyone in kirkwood!
Response from the owner: Thank you for choosing Thomas Hoffmann HVAC! We're glad we could promptly address and resolve your HVAC issue. Appreciate your recommendation!
Punctual / friendly / great service !!Highly recommend!
Response from the owner: Thank you, Mike! We're so glad you had such a positive experience with our technicians—your recommendation means a lot to us!
Having Nick come to our aid was a great experience and he offered followup assistance with the fancy technology part of the appliance if we need it. We will call him again if the need arises. Merry Christmas.
Response from the owner: Thank you, Marilyn! We're glad to hear that Nick was able to assist you and provide follow-up support. We appreciate your trust in us and wish you a Merry Christmas!
These guys are pros.Techs are friendly, listen and explain what they are doing.Office staff is responsive.Fast service....
Response from the owner: Thank you, Clark, for your kind words! We're glad to hear our techs and office staff made your experience a great one. Your feedback means a lot to us!
Nick was a true expert in explaining our options for a new thermostat.
Response from the owner: Thank you, Robert, for your kind words about Nick's expertise; we're glad he could help you with your thermostat options!
My AC unit was located on the ground in a very undesirable area; in the direct path of my neighbor’s downspout. Sent pics to Thomas, got a reasonable estimate to raise the unit off the ground and bolt it to my foundation. The work was completed cleanly and efficiently at a very reasonable price! Extremely satisfied with their work!
Response from the owner: Thank you, Diane, for your wonderful 5-star rating; we appreciate your support!
Notified me of expected arrival time and then again when he was on his way and was exactly on time! Nick was very personable and trustworthy.
Response from the owner: Thank you, Maureen. We're glad to hear that Nick kept you informed and made your experience enjoyable!
Thomas Hoffmann AC & Heating was wonderful to work with. They arrived on time, diagnosed the issue and got the work done fast. I would recommend Thomas Hoffmann AC & Heating to anyone.
Response from the owner: Thank you, Adam, for your kind words and recommendation; we're glad to hear you had a great experience with our team!
Tom and his team helped us select a great 2nd unit for our first floor. Installation went smoothly and it looks great. Cheers!
Response from the owner: Thank you, Immy! We're glad Tom and the team could assist you in finding the perfect unit and that the installation went smoothly. Enjoy your new space!
Arrived early in the time window quoted. Zach is a thorough tech and discovered an issue I had suspected. Able to quickly get the part and fix the issue. Great company to work with. The communication before the appointment is outstanding. Highly recommended.
Response from the owner: Thank you, Dale, for your wonderful feedback! We're glad Zach could assist you effectively, and we appreciate your kind words about our communication and service.
Excellent Service. Thank you Zackery
Response from the owner: Thank you for your kind words, Buzz! It was a pleasure assisting you.
I'm a new customer and had my first appointment for furnace check.My tech was Zack and what a professional. He explained how he checked system and answered all my questions. This was a very good experience
Response from the owner: Thank you, Patricia, for your kind words! We're glad to hear that Zack provided you with a professional and informative experience during your furnace check. Your satisfaction means a lot to us!
Thomas Hoffman was so helpful. They even helped me set up my nest thermostat.
Response from the owner: Thank you, Krista, for your kind words; we're glad Nick could assist you with your nest thermostat!
Service was on time and did a quality service of my two systems.
Response from the owner: Thank you, Paul, for your kind words about our timely and quality service; we appreciate your feedback and are glad to hear you were satisfied with your systems!
Excellent customer service. Reasonably priced. My go-to for any HVAC needs.
Response from the owner: Thank you, John, for your kind words; we appreciate your trust in our team for all your HVAC needs!
Zachary is a very efficient worker and explained the work he did well.
Response from the owner: Thank you, Joseph, for your kind words about Zachary's efficiency and clear explanations; we truly appreciate your feedback!
I called on December 25th at midnight and started leaving a message and Thomas Hoffman the owner called me back almost immediately. He said he would come out the next morning between 8:00 and 10:00 am snd he was promptly on time. He fixed my problem and while he was there I decided to get an estimate for a new furnace and air conditioning unit. The price was very reasonable and the installers one of them being his son were both very professional very courteous, polite, arrived on time and finished the same day. I enjoy knowing that I now have the support of Thomas Hoffman heating and air conditioning along with the peace of mind that comes with owning a Trane. Nothing stops a Trane.Albert Koesterer
Response from the owner: Albert thanks so much for your kind reviews and your business. We truly appreciate it!!!
Great service! He set the thermostat to reach a certain temp and then go to a lower temp. Then in the AM go to a higher temp.He is patient and quite knowledgable.Dick Drummond - Kirkwood
Response from the owner: Richard, thank you for your kind words! I'm glad to hear you had a great experience with our services.
Zachary was here on the dot at 8:00am. Thank for making me the first stop as promised. Very friendly too.
Response from the owner: Thank you for recognizing our professionalism and friendliness!
Nick from Thomas Hoffman came for our spring check up. Nick is the best. He takes such good care of us. He has been taking really good care of us for several years.
Response from the owner: Thank you for your kind words about Nick! We appreciate your loyalty and trust in our services.
Excellent service
Response from the owner: Thank you for your kind words, Ella! We appreciate your feedback.
I have complete trust in Thomas Hoffman AC . I have had multipletechnicians who are always polite and knowledgeable.
Response from the owner: Thank you for your trust in our team, Henry! We appreciate your kind words about our technicians.
Just had our annual service on our furnace. The technician was very professional, friendly, thorough and spent time explaining what all he did and what his recommendations were going forward. Couldn't be happier. I HIGHLY RECOMMEND THOMAS HOFFMAN AIR CONDITIONING AND HEATING.
Response from the owner: Terry, we're so grateful for your kind words and for recommending us! We're thrilled to hear that you had a positive experience with our technician during your annual furnace service. Thank you for choosing Thomas Hoffman Air Conditioning and Heating!
Zachary was very professional and friendly and we would be happy to have him return to work on our furnace again in the future!
Response from the owner: Stephanie, we're so happy to hear that Zachary provided you with professional and friendly service! We look forward to working with you again in the future!
Excellent! Highly recommended
Response from the owner: Udis, we truly appreciate your recommendation!
I called on a Monday morning as air conditioning was blowing warm air. They were able to come to my house very early afternoon and fixed the problem. Would highly recommend and will use them again.
Response from the owner: Becky thank you so much for your great review. We appreciate your business and your kind words.
This company is so responsive to me that I love them. They respond immediately and I trust them. It always cost me, but that is the nature of the beast. I haven’t been steered wrong yet. They are genuinely nice to work with and honest. I use their maintenance program as well. Highly recommend.
Response from the owner: Thank you for your kind words, we truly appreciate your trust in us and are glad to hear about your positive experience with our services.
They were outstanding and got us cool very quickly.
Response from the owner: Bill, we're so glad we could help you out quickly! Thank you!
Great job done quickly and I loved how they were on time. Thank you for providing great customer service.
Response from the owner: Myrtle, we're so glad you're happy with our service. Thank you for your kind words!
Giovanni was good…. This is reason we ask for him
Response from the owner: Thanks so much!
Zac and Giovanni are always extremely polite, considerate and professional. We are thrilled to have the new A/C unit. Our unit was 18 years old and stopped working in the thick of 100 degree weather. Tom (the owner) came over within an hour (after hours) and bought us time by changing out some parts until we could have the new one installed. We’re very happy with Thomas Hoffmann A/C and Heating!
Response from the owner: Katie, we're delighted that Zac, Giovanni, and Tom were able to assist you promptly and effectively during the heatwave. Thank you for choosing Thomas Hoffmann A/C and Heating!
Honest takes his time to listen and help you without charging Arm and a leg
Response from the owner: Thank you so much for your kind words, Carrie! We truly appreciate your feedback.
Couldn't be happier with our experience. Our AC stopped working after typical hours and they were the only "24/7" HVAC service who was able to come out same day. Not only were they fast, but they identified and fixed the problem immediately and did some preventative maintenance (and showed me how to do it) to prevent it from happening again. Will absolutely use them again in the future.
Response from the owner: We're so glad to hear about your positive experience, Hannah White! Thank you for choosing us and we look forward to helping you again in the future.
Great service! Prompt, polite and got the job done quickly.
Response from the owner: We're so happy to hear that you had a great experience with us! Thank you for your kind words.
Thomas Hoffman personally quoted the job at a fair price and they did a quality install! I would highly recommend them!
Response from the owner: Thank you for recommending us, Joe! We appreciate your feedback and are glad you were satisfied with our service!
Came same day and fixed the problem.
Response from the owner: Thank you for your feedback! Glad we could help you out the same day.
Caught in a bind one evening (no AC), I called for an appointment to get mine repaired. They came out the next morning, one half hour early! Within 30 minutes we back up and running!! Thank you, Thomas Hoffman. You are my guys!
Response from the owner: Thank you for choosing us, Sue! We're glad we could help you out quickly and get your AC up and running smoothly again! Thomas Hoffman and the team appreciate your kind words!
Blower went out on a Sunday. They answered my call, got me in, replaced blower, very easy!
Response from the owner: We're so glad we could assist you with your blower on a Sunday! Thank you for sharing your experience with us.
Thomas is amazing and came over in only a couple hours and fixed my ac! True life saver 🙏🏼
Response from the owner: Thank you for sharing your experience with Thomas! We're glad to hear he was able to help you out quickly and efficiently. 👍
Fantastic experience! Our AC went out on a scorching Saturday evening. I wasn’t actually expecting anybody to get out that night, but when calling - I immediately got an answer, was on the schedule in 5 minutes, and Thomas showed up an hour later. He was honest, professional, and educational. Most importantly, I didn’t feel like he was cutting corners or trying to get in and out… a welcome contrast from most services these days. 6 stars out of 5, highly recommend.
Response from the owner: Thank you for sharing your experience, Andrew! We're so glad to hear that Thomas provided such honest and professional service for your AC needs. We truly appreciate your recommendation and look forward to serving you again in the future.
What Is MERV?
MERV stands for Minimum Efficiency Reporting Values. This rating measures how well a filter stops and contains airborne particles between 0.3 and 10 microns large. This includes dust, pollen, mites, and mold spores.
MERV ratings range from 1-20. A lower MERV rating only stops large particles of dust and pollen. A higher MERV rating contains all particles down to a much smaller size and will improve your indoor air quality without making your energy costs rise significantly.
MERV Rating Chart
MERV Rating
- MERV 1 – 4
- MERV 5
- MERV 6
- MERV 7
Average Particle Size Efficiency in Microns
3.0-10.0 microns at 20% efficiency
3.0-10.0 less than or equal to 20%
3.0-10.0 less than or equal to 35%
3.0-10.0 less than or equal to 50%
1.0-3.0 less than or equal to 20%
3.0-10.0 less than or equal to 70%
1.0-3.0 less than or equal to 35%
3.0-10.0 less than or equal to 75%
1.0-3.0 less than or equal to 50%
3.0-10.0 less than or equal to 80%
0.30-1.0 less than or equal to 20%
1.0-3.0 less than or equal to 65%
3.0-10.0 less than or equal to 85%
0.30-1.0 less than or equal to 35%
1.0-3.0 less than or equal to 80%
3.0-10.0 less than or equal to 90%
0.30-1.0 less than or equal to 50%
1.0-3.0 less than or equal to 85%
3.0-10.0 less than or equal to 90%
0.30-1.0 less than or equal to 75%
1.0-3.0 less than or equal to 90%
3.0-10.0 less than or equal to 95%
0.30-1.0 less than or equal to 85%
1.0-3.0 less than or equal to 90%
3.0-10.0 less than or equal to 95%
0.30-1.0 less than or equal to 95%
1.0-3.0 less than or equal to 95%
3.0-10.0 less than or equal to 95%
The most efficient air filter is called a HEPA filter. HEPA stands for high-efficiency particulate air. This air filter can theoretically remove at least 99.97% dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns.
Contact Thomas Hoffmann Air Conditioning and Heating
Whether you’re a business manager or a homeowner, Thomas Hoffmann Air Conditioning and Heating can help you determine what type of filter is right for your needs. With more than 30 years of experience and a master technician and mechanical engineer as our owner, we can replace, repair, and provide maintenance for your business or home’s HVAC system.
24/7 Service Call Now
At Thomas Hoffmann Air Conditioning & Heating, we pride ourselves in being a locally owned and operated HVAC company. With more than 30 years of experience and a master technician and mechanical engineer as our owner, we can replace, repair, and provide maintenance for your business or home’s HVAC system.
