Cold Air Returns.........

[OAG]

Our newer home in the central OH area seems to follow the previous posting to the letter (almost). All of our heat registers are at floor level with the air returns set into the walls, away from the registers, near floor level. The only exception is the basement (partially finished) which seems to have it's own weather system, cool in the summer and warm in the winter - most comfortable area of the home. We use ceiling fans to move the summer air down and around but do not use them in the winter (do not see much need then). Helps a lot to have the "set-back" thermostat to regulate the heating and cooling.

 

[45th Birthday]

In the winter, open the lower level (thereby closing the upper level). In the summer when the central air conditioning is running, close the lower level (thereby opening the upper level).

Our house was not built with this new fangled technology, but when we had a new HVAC system installed, they added this feature using the space between the wall studs as the ducts between the upper and lower levels. It does a nice job. Rooms have a more even temperature distribution by using the floor mounted return in the winter and the ceiling mounted return in the summer.

Our 1970s-era house had these in every room, except that opening one did not close the other and there is actual ducting running between them. I understood that the top was to be open in summer, bottom open in winter as mentioned here.

When we completely renovated the house, all these needed to be replaced. Our builder said they don't install the adjustable returns any more (and might have said something about more efficient HVAC systems today-I don't remember exactly). Anyway, we replaced them all with permanently open grates.

We don't really notice any difference in comfort.

 

[ls99]

As result of all the foregoing hot air, is Finance Dude freezing his a$$ets or sweating it out?

 

[jazz4cash]

By now, you probably wish you'd never asked.....

What I am asking is WHEN do I close off the supply (lower) grilles?

It seems we've established that you have upper and lower RETURN grilles. It's an interesting setup and has some value. Many newer homes have a single huge return (or one per floor) for the whole system.

Now you must report if opening the lower grilles closes off the upper grilles........and

Where are the supply grilles..........the one's that blow air out when the heat is on?

It seems likely that the lower returns should be open in the winter as the air should be cooler near the floor. Even if there is no diverter function, I am guessing that when both upper and lower grilles are open, less of the heated air near the ceiling will be drawn into the return.