I run my furnace fan all the time and my filters (3M Filtrete 1000) generally are saturated after 3-4 weeks. It seems strange to me that they pick up so much dust, considering that we never open our windows (primarily due to allergies). We also keep our house (6 years old, the ducts have been cleaned) pretty spotless, so I'm not sure where all the dust is coming from. We run the fan all the time for two reasons: it lowers the level of dust in the house and it keeps temperatures more even throughout our 2-story (plus basement) house. Running an AirAdvice report didn't identify any high levels of dust, just low levels except when lots of activity is happening in rooms.
I'm having an Aprilaire 5000 air filter installed in my home and while I'm at it, I'm considering putting in a fresh air intake (something like the Scuttle 216).
I'd like your thoughts on fresh air intakes. The reason I'm considering this is I have very slight drafts around double hung windows (through the contact felt on the sides of the windows) and I thought that perhaps the intake will create enough negative pressure to prevent some of the air flow around windows and doors, thereby preventing some dust/drafts from entering my home. Also, I'm sure getting fresh air continually added to the HVAC probably is a good thing.
(1) Is a fresh air intake more trouble than its worth, especially near Chicago, with its hot summers and cold winters? Will I introduce significant workload to my AC and heating when it has to work overtime to heat/cool a steady flow of outside air?
(2) If I run my fan all the time, how should I have the fresh air intake set up? Normally I believe it opens when the fan turns on and closes when the fan turns off. I'm not sure I need the intake open all the time, so I thought perhaps a timer (with an override for very hot or very cold days) would be best.
(3) What diameter intake would you consider adding?
Any thoughts regarding fresh air intakes would be appreciated.