Honeywell F500 whole house filter

[JWB]

Went to a very particular customer's house the other day and she had one of these mounted as the instuctions show in the return. It was wired to run all the time, no "sail" switch. This customer is very sensitive to indoor air and willing to spend for comfort.....

I am at a loss to understand how a unit installed with the inlet and outlet less then 2 feet apart benefits by running 24/7.

http://customer.honeywell.com/techli...0s/68-0263.pdf

[pmeunier]

I am at a loss to understand how a unit installed with the inlet and outlet less then 2 feet apart benefits by running 24/7.

Bypass installation assumes that the furnace fan is on. The flow of air prevents the air from "looping" between the outlet and inlet, even if they are close. If she wants to benefit from it, the thermostat needs to set the fan to always on. I despise the bypass installation because it's so inefficient. That filter should be ducted independently.

My opinion, supported by published research and by my own measurements with a particle counter, is that the best use for a HEPA filter is to bring in fresh air and prevent the infiltration of dust and allergens with the constant outflow of air.

[JWB]

So bypass installation needs to only be on when the fan is on. I was staring at that thing running in her garage getting pissed. I just thought it was wrong, but had no data at all but my own common sense to back it up.

I don't think we are going to get the $$ from her at this stage in the game to retro fresh air in and fresh air out duct, but at least I can wire that thing to run only when the blower has a call.........thanks.

[pmeunier]

She's lucky to have someone who cares working on it.

[genesis]

Bypass installation assumes that the furnace fan is on. The flow of air prevents the air from "looping" between the outlet and inlet, even if they are close. If she wants to benefit from it, the thermostat needs to set the fan to always on. I despise the bypass installation because it's so inefficient. That filter should be ducted independently.

My opinion, supported by published research and by my own measurements with a particle counter, is that the best use for a HEPA filter is to bring in fresh air and prevent the infiltration of dust and allergens with the constant outflow of air.

Ditto on what he said. Well spoken.