How To Tell If Your MERV Air Filter Is Protecting You From Viruses Or Only Catching Dust: A Homeowner’s Field Test From An HVAC Inspector’s Playbook
Most of what gets called a Minimum Efficiency Reporting Value (MERV) 13 problem turns out to be an installation problem with a filter rating. We learned this on a January call in Costa Mesa. The homeowner had upgraded her filter a month before our visit, and the registers were already gray. Her system was running … Read more