# Review duct cleaning, moisture and filtration proposals

Lesson 2 of [Manage HVAC and indoor air quality projects](https://hvacpros.fyi/academy/manage-hvac-air-quality-projects.md), 10 minutes.

Indoor-air proposals often combine cleaning, chemical treatments and filtration in one offer. Review the purpose and evidence for each item separately. EPA's duct-cleaning guidance is for homes, and its air-cleaner page describes residential products. These sources help you question claims within th…

The rest of this lesson is for learners enrolled in the course. [See how Manage HVAC and indoor air quality projects works](https://hvacpros.fyi/academy/manage-hvac-air-quality-projects.md).

Also on the [web page](https://hvacpros.fyi/academy/manage-hvac-air-quality-projects/review-cleaning-and-filtration).