Balancing Act

jdhamhock · 02-20-2010, 08:06 AM

I have a house and hvac system that are 37 years old, the upstairs registers don't put out nearly enough airflow. I was thinking of downsizing my 1st floor ducts from 6" to 4" in an effort to balance the system. Any thoughts?

yuri · 02-20-2010, 08:53 AM

Why not just close some downstairs dampers to force the air upstairs. Not rocket science.

. You have to be careful to not reduce the airflow or the furnace will overheat and the A/C will freezeup if you have one.

jdhamhock · 02-20-2010, 11:09 AM

Your right, it's not rocket science however it's not grade school stuff either. I'm not a pro which is why I'm here, I am a pretty good all around tradesman with 12 years construction under my belt. The problem is that I do in fact have some of the downstairs registers closed but it is not really improving the situation. Unless my only solution is to close all registers for the floor I'm not on...lol

. I thought by decreasing the 1st floor airflow it would increase the 2nd ( thus balancing ) but maybe it's not that simple, maybe my only other choice is to install duct booster fans?

**beenthere** · 02-20-2010, 11:54 AM

Do you have central A/C also.
If so, when is the last time the indoor coil was cleaned.
What type of air filter are you using? Is it a restrictive 3M filtrete? If so. Use a less restrictive air filter.
Is the blower a belt drive, or direct drive. If belt drive, is the belt loose?
Do you have any returns blocked or cover. if so, unblock/uncover them.

Marty S. · 02-20-2010, 12:53 PM

Could also be the duct work running upstairs is too small and it's doing all it can. Check the things that beenthere mentioned first then close all the lower registers and check air flow upstairs. If it's still weak then new duct or a seperate upstairs system is your answer.