We had ours done. And had air testing done for molds, dusts, etc. excellent service. We did have higher than normal range for some mold toxicity so we had the house air scrubbed and treated and then had the ducts cleaned. If the hvac people doing the cleaning are professionals at it, anything that is stirred up within the ducts stays in the ducts and gets sucked out. They loses and covered the vents! And I too run air purifiers. We also put a uv lamp (NO OZONE) in our hvac system and had the filter box changed to a 5" filter box. It has helped tremendously.