Air conditioning

[GermanMom]

I did some additional insulation in my house and installed another storm door in the front to increase cross ventilation. I am pleased with the results. This summer I did not have to turn on the air conditioner yet. The main level in always a comfortable temperature. On a 97 degree day it might get up to 78 degree on the main level. However the second story of my house where my toddlers sleep gets into the upper 80s on a hot day. Which makes nap time uncomfortable for them. I can give them a nap in the basement where it is nice and cool, but I was wondering if there was not a way to change my venting so that the air conditioner would blow only into their room. I also don't like that I have to heat my basement in the winter eventhough nonone hangs out down there unless I have guests.  I learned fom a HVAC guy that closing all other vents is not efficient and that for optimum efficiency of heating and cooling all vents need to be open. Can anyone explain this to me or have any ideas on how I could change the way my heating and cooling vents into the house?

[begood]

I got a lot of good ideas here:

http://forum.mrmoneymustache.com/ask-a-mustachian/looking-for-ideas-to-cool-our-house-more-efficiently/

All I can tell you about the vents thing is that we flipped a lever on some ductwork in the basement and closed all the vents on the first floor and all but the ones in our bedroom and our daughter's bedroom on the second floor, and the airflow is much stronger now to the second floor. We used to have a 5-6 degree difference between floors; now it's 1 degree.

I'm not saying your HVAC guy is wrong, just relaying our experience.

Do you blow a fan on your babies at naptime? That can help make it feel cooler.

[GuitarStv]

We close all vents on the basement and lower floor in the summer to pump the cool air up to the higest floor.  It then falls down and the house is a more even temperature during the summer.  In the winter we do the opposite, opening up the vents in the basement and lower floor and close all the vents on the upper floor.

I'm not saying your HVAC guy is wrong either, but in my experience what we're doing keeps the house a more even temperature.

[guitar_stitch]

Closing too many vents will cause the airflow across the evaporator to be insufficient.  This can lead to icing.  You could also pop any weak ductwork due to pressure.  (Bad joints, weak and deteriorated ducts).

In your case, a portable chiller may prove to be more efficient.  Cool just the room you're wanting cool.

[zolotiyeruki]

The HVAC tech is right about the loss of efficiency.

The "proper" way to cool just the upstairs is to install a zoning system on your HVAC, or install a second HVAC system and have each system supply one floor.  That's expensive, though.  Another option is to set your thermostat to run the fan all the time during the day, so it recirculates air throughout the house.

You might also consider installing a radiant barrier in the attic, as well as more insulation.

[Tjat]

I'd recommend a wall ac unit to cool that one room. Or, let them nap in the basement like you mentioned

closing off vents is a bad idea as previously mentioned.