A hot Air question

Jim_47

Guys a little help with this idea please.
Has anyone entered outdoor air into the return air duct to provide a healthier enviroment in the home? Is there any literature on this topic? Any help is appreciated as always

Tom_35

Fresh air

Go to Fieldcontrols.com and look at their metering air system (MAS). We have used this damper extensively and it works well. The air that is brought into the house first goes through the return air duct system and is filtered, then comes through the supply air ductwork.

Works with a barometric damper that replaces air that is exhausted through fire places, exhaust fans, flues, clothes dryers, etc. Keeps the home from "going negative" and bringing in air through window cracks, doors, backdrafting, etc.

Tom Atchley

ernie_3

yeah but...

NO workie too well w' A/C. Economizer packages however did take A/C into consideration.

Tom_35

yeah but

Ernie, when air is exhausted from the home via the exhaust fans, clothes dryer, flues, etc during the summer---where does the air come from to replace the air that has been exhuasted?

Air has to be replaced when it is exhausted outside the building envelope. It can either come from a controlled device (fixed fresh air damper, a metering air system, or some sort of economizer), or an uncontrolled method, such as through leaks around windows, doors, through can lights in the ceiling, fireplaces, etc. When it comes through the uncontrolled way, the customer gets more dust and drafts.

Most residential systems aren't set up for an economizer.
We have Energy Recovery Ventilators available now that work really good---the downside being they are pretty spendy. I have one on my home, but most of our customers choose not to spend the dollars for an ERV, and go with the MAS.

TA

heatingman_2

fresh air

fresh air good thing 4"line 40 to 50 cfm undersize return by 60to80cfm work,s well dosn,t seem to mess with ac have done this many times over 30+years

harvey

aprilaire

go to the aprilaire website and check out their ventilation control. cycles fan as needed or wanted, monitors outdoor temps. works well as do all aprilaire products do. around $100 on the shelf

ernie_3

I agree Tom

Certainly there is infiltration and exfiltration and clearly there is a need for make up air when negative pressure exists. But the original post was bringing fresh air into the return ducts, for volumetric change. That's where the ERV's come in. I would advise just bringing fresh air into R ductwork if anERV is not present.

Tom_35

Fresh air

Ernie, I agree with you on the fresh air duct. Kind of got side-tracked with the fresh air duct and making up for air that had been exhausted needing to be made back up.

TA

Jim_47

fresh air

Yes my major reason is to just bring in "a little" fresh air into a stuffy smokers house. (grandma's) Since I am replacing the HA furnace I thought a little addional fresh air would not be noticed by Grandma but the rst of us would all breath a little better.