HERTSMI-2 is the most accurate. Often houses will pass air spore tests but HERTSMI-2 will catch the problem. It isn't necessary to do an ERMI - that tests for ALL molds in your house. You only need to test for Mycotoxin producing molds, which the HERTSMI-2 does.
Only costs $130. Buy the Swiffer kit. Vacuum is not as accurate. Clean the whole house, then wait 2-4 weeks, then use the Swiffer kit to collect dust that has settled in the bedrooms and living room. Don't do kitchen or bathrooms.
Interpreting a HERTSMI-2:
0-8: Excellent
9-10: Good
11-15: Possibly dangerous. Deep clean the whole house, especially locations that are rarely cleaned and have settled dust like the tops of ceiling fans, door frames, blinds, etc. Wait 2-4 weeks and retest. If the score is still 11 or above, you have a significant mold problem that needs to be found and remediated by professionals.
16-50: Dangerous. You have a significant mold problem that needs to be found and remediated by professionals.
I use companies licensed in mold remediation and testing. If you live in a fairly populated area and google “mold air testing in (x city)” you should hopefully find something. It’s strange to me how infrequently these services are utilized. My realtor, who is one of the most experienced in the state even wasn’t sure who to go to for this when I first asked
There's some care to take here, especially depending on state licensing requirements. In some places it's particularly easy or low risk to present fraudulent results or interpretations of results on air tests so they can pitch expensive but unnecessary mitigation. National and regional chains often provide licensing cover for, and set quotas on, operators that enable some of this scamming.
One way to vet a mold tester is to go through a property management or landlords' association, even if you're not either of those things (even if you're a renter!). They often refer or have a list of vetted local contractors publicly available. Nobody likes wasting money on property less than a landlord.
100%. for this reason it can be ideal to go with a company that only does testing, not remediation. In smaller markets, though, you might be forced to go through a company that does remediation as well. Had to do it recently but they were honest and helpful, gave us a clean rating