Keep your returns free and open to pulling in the air.
Sounds simple? Approximately 10% of the homes and businesses we enter have some sort of obstruction in front of the return. The return is the bigger vent in your home or office. It most likely is the dirtiest vent in your home. This is where the air circulating systems sucks into the HVAC coils the air it is going to cool or heat. If you put a dresser, credenza, bookcase, couch, etc. in front of this, you are limiting your system from getting fresh air and are breaking the desired cycle of circulation.
Circulating, dry air is the enemy of mold. Mold likes stagnant, moist air. Blocking the return most likely leads to warmer, moister air that is beneficial to mold or fungal growth.
Do NOT block or close off supply vents.
You may think you are saving money by closing off vents. In actuality, you are stopping the air from circulating, causing it to get stuck in the supply duct. It will stagnate in the supply duct. Remember? Circulating dry air is the enemy of mold. Shutting off multiple vents causes even more stagnant air. Mold or fungal growth will most likely happen. Your system will run less efficiently and mold spores will most likely form in the stagnant supply and then migrate to the rest of the system.
If you have committed either one of these errors, do not despair. It is fixable. Unblock the returns. Open up the vents. Then contact Mr. Duct Cleaner and schedule your duct cleaning. Our estimates are FREE.