Forced air heating - what do you put over your vents to prevent dust from going in them?

Question

I bought the precut filter squares for my registers, but they are too small. Also I need to find something to put on the larger cold air return registers. Looks like cotton batting or something is on there right now. It is so dirty I need to replace it with something else. My mother said her friend uses cheesecloth. What do you recommend?

Answer 1

cheesecloth is just fine to use as it wil allow the air flow to stay the same...just need to replace or clean every month..have seen many people use them .you do not need this on your return air duct as there is a filter in it before the furnace..

Answer 2

The filtration should be at the inlet to the system... the filters in the HVAC unit and possibly return vent.

If the system is going to be turned off and you just want to keep junk out of the floor returns, I suggest plugging the with old t-shirts.

If you have high levels of dust coming OUT of the vents, there are 3 checks:

1) Make sure that air handler filters are replaced, the right size, and installed properly
2) Have the ducts cleaned
3) Make sure that there are no breaks in the duct work... I have seen situations where a torn duct in the attic pulls in the cellulose (brown paper bits) insulation and sprays them about the house.

I recommend a complete system tune up every 5 years in any event- and discuss the performance issues with your technician. The $100 or so service call will pay for itself many times over in reduced energy bills and comfort.

Best of luck

Answer 3

Most furnaces don't need anything except the main filter (sometimes there are 2 filters, one on the intake air grill and one at the furnace itself). I would think cheesecloth would work since it is quite porous. The vents expell air into the room so should not need any type filter if the other filters are in place.