Messages and Online Forum Q&A

Re: Adding additional air ducts in unfinished basement

From: info@builderswebsource.com
Category: HVAC
Remote Name: 63.198.181.43
Date: 27 Sep 2001
Time: 07:15 PM

Comments

Do you have direct access to the supply and return manifolds? Depending on how your heater is configured, essentially you need to provide additional "tentacles" off the supply and return manifold to supply a proper amount of air. If you have to tap off an existing line, you risk changing the heating efficiency in other parts of the home. You also need to be sure that your existing heater is sized to handle the added BTUs that will be required to heat the finished basement.

Since computing this can be tricky, we strongly recommend that you consult with a heating company that can run the calculations for you. They can also recommend or supply the custom pieces that will be required to retrofit your existing furnace to handle the extra branches.

I've seen many a remodel where the contractor simply tapped off an existing branch line to supply a new addition. Needless to say, this rarely works properly unless the entire branch and supply lines are resized accordingly. What ends up happening is that parts of the home that were once comfortable, are now too cold...and the furnace is cycling too frequently to operate efficiently.

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