I had been working with HVAC for over two years, in their bookkeeping department. I thought I knew all there was to know about HVAC, but I was wrong. I had never heard of MERV. I had a customer call and ask me what MERV would be best for her new furnace. She was confused by the color ratings on the air filters and by the MERV. I told her that I was unsure, and I called a HVAC technician into the office to have him give her his advice. Apparently the higher the MERV rating, the more efficient the air filter is. While listening to him talk to her, I found out that MERV is an acronym for Minimum Efficiency Reporting Value. The company she was ordering her air filters from, made it a bit simpler to know if you had a MERV rating or a low. Their Bronze air filters had a MERV of 6. Their Silver air filters had a MERV rating of 8. Their Gold air filters had a MERV rating of 11. The rating was developed by a group of HVAC engineers to help rate the effectiveness of the air filter. Not all air filters are alike. There are many different sizes and there are those that are HEPA filters. The HEPA filter has one of the highest ratings, meaning that it can pick up on minute germ and microorganisms that can contaminate the air quality. From now on, when I go to buy my air filters for the furnace or the air conditioner, the first thing I will be sure to do is check the MERV. Why have an air filter, if it isn’t doing a great job.