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tnrandy
06-30-2009, 02:56 PM
I built a 600sq ft addition and need to run some hvac lines to it. The main trunk line is 16" (I think) and is located about 35' from where the new lines need to come up from the floor. (crawlspace) What/how is the best way to do this? Should I run a 10" rigid duct to midway the addition and run flex drops off that or what? I've talked to a few handy men and they have varying opinions. I haven't called a pro yet, thought I'd see what kind of advice I could get here first. Also, will I need to add any return?

Thanks
heaterman
06-30-2009, 03:51 PM
Too many other variables to really help you out. You are going to need more than a "Handy Andy" if you want to insure proper conditioning of your living space. Heat loss and gain calcs. (manual J) along with proper duct design (manual D ) are necessary. Way beyond DIY, which is against open forum rules anyway. Call a couple local HVAC companies for estimates.
tnrandy
06-30-2009, 03:56 PM
Too many other variables to really help you out. You are going to need more than a "Handy Andy" if you want to insure proper conditioning of your living space. Heat loss and gain calcs. (manual J) along with proper duct design (manual D ) are necessary. Way beyond DIY, which is against open forum rules anyway. Call a couple local HVAC companies for estimates.


Thanks for the advice. When I posted I thought this was a DIY site but I just read where it is not.

I'll have the original installer come out and take a look.

Thanks again.
beenthere
06-30-2009, 04:37 PM
Best idea, is to call your installer.

He needs to determine how much heat and cooling the additon needs. Then he can determine if your existing unit can handle the addition. And advice what he needs to do from there.
motoguy128
06-30-2009, 04:43 PM
Just adding new ductwork on the existing system will change it's air balance as well as adding a load to the existing system.

Fortunately many systems are oversized anyway, so there is a chance you may be able to make some ductwork alterations and the existing equipment afterwards may even perform better.


I know a 600sqft addition to me home would solve several of my issues...along with some of our space issues. But each home is different.