Home ventilation

[speedymonk]

I've been in my new place about a year and have been dinking with various things to reduce energy consumption. I've added a modest amount of new insulation (ceiling to R-50) and a radiant barrier upstairs, switched to CFL's and basically use common sense to turn stuff off when not using it.

My air handler seems to run about 15-20 minutes every hour for ventilation purposes. That chews up a fair amount of KWH a month. The Honeywell IAQ stat has settings to control CFM (don't know if that would work with my Trane XL 14i and 2TXCB048AC 3HCAA air handler) and a setting to have ventilation with the fan on or off. It also has a setting for ventilation limits of 30%, 50% and 100% Does ventilation work without the fan? I admittedly am confused, but then again my wife insinuated that when we got married.

[housesmart]

There is often a air intake attached to the side of your home (4" pipe) to the return air side of your furnace. When the fan runs it draws from your rooms at the return air grills and brings in approximately 5% out side air to give better ventilation into your home. This gives your home a posi9tive pressure for a litle while and your stale air is pushed out of your home.
If you ever up grade your furnace - go to a variable speed for slower fan and constant air flow. If you do not have bathroom fans - get them and run them for 20 minutes after showering. Possibly look at heat recovery ventilators.

[speedymonk]

I run the fans about 20 minutes after showering so that's ok. My question, though, Does the house vent without use of the fan on the air handler? The options are 1. ventilation forces fan on and 2. ventilation does not force fan on.

Is forced ventilation via a fan in a tight house (Built Green level 3 with upgraded Low E2 windows, and sealed well) necessary or is there "passive ventilation" (not open windows)? Obviously I'm pretty unclear on this. I figured one of the fine folk on this site would probably know. They've have been most helpful in the past.

[beenthere]

You'll have to look to see if they installed a forced system. Or are just using the A/Cs blower.
If its a pipe tied into teh return duct. look to see what size it is, and if it has a damper.

A tight house will need mechanical ventilation.

[speedymonk]

Ok...looks like there are two PVC 2-1/4 (eyeball guess) pipes coming out of the top of the furnace/air handler that run to the exterior wall and into what appears to be an outside vent. Can't tell if it has a damper unless it is inside the external vent box. Mounted a little high up on the house. I'm guessing this needs to be forced ventilation, then.

[beenthere]

That would be the intake and vent for teh furnace burner, not fresh air for the house.