HVAC rough in

[paul guerra]

I am roughing in my vents (6")..Is there a general rule of thumb for a 6" supply to square footage? I am trying to figure out how many I need.

[edward301]

There is a whole lot more than that to it. Some
bath rooms may only need 4", bigger rooms may need
8", so on. Have you done a Manual program?

[paul guerra]

I guess not since I don't Know what a Manual program is. Can you help? I doing an addition on my home and ran out of money and have to figure this out on my own.

[coolwhip]

Ugh!

[billva]

are you tapping off of the existing system or installing a separate system here? if you are tapping from the existing, and it was sized properly now it will not be sized properly. trying to save money is going to cost you more.

[edward301]

A Manual D is a calculation program that will size your
ducts for each room in the home, taking consideration
into construction, windows, climate so on. This
assures you get proper airflow, into each room, and
do not have certain rooms that get too hot, or cold
compared to the rest of the home.

A 10x10 room could use a 6" duct, but larger may
need a 8" or even a 10" duct. And don't forget
to have a decent sized return air duct, or all those
ducts will sufficate.

[paul guerra]

I am installing a air handler upstairs and a condensor outside ( not sure of size of course )to serve only upstairs bedrooms. My existing unit will still serve down stairs.

[arc8]

Hard to believe, but true!

A 10x10 room can use one 6" rd duct for a certain place and a particular house. A 10x10 room can use two 6" rd duct for another place and particular house. And a 10x10 room can use three 6" rd duct in another place for a particular house.

So, what type of house and location are you in?

You need manual D performed! But you need Manual J first before the equipment is selected, then do manual D!

[Irishmist]

This process will cost you far more than you invest by going with a professional. There are a variety of financing programs available, and this is NOT a do-it-yourself project! Rather than have to pay someone to come behind you later and straighten it out, why not make the up front investment to have it done correctly? Our knowledge, experience and application know-how is the value that we (in the industry) bring to the table. Hope you follow this advice! All the best, John.

[billva]

this sounds like a petri dish in the making. i hope your homeowners insurance covers mold damage.

[jrbenny]

Originally posted by paul guerra
I am installing a air handler upstairs and a condensor outside ( not sure of size of course )to serve only upstairs bedrooms. My existing unit will still serve down stairs. While I'm sympathetic to your lack of funds (I'm building a home now...OMG...I'm broke)...



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You really need to find a way to pay for a professional to assist you with this part of the project.