# Ductwork to 3 Season Room



## laplow (May 22, 2008)

I am planning on extending my existing ductwork in the house, through the cinder block and outside to go underneath an existing deck.  My 3 season room is built on top of the deck.  Can anyone point me in the right direction on how to do this?  I never did any ductwork before?

Thanks!  

I am located in Wisconsin.


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## AU_Prospector (May 26, 2008)

I have a picture in my mind of you punching holes in your cinder block crawl space/foundation to vent forced air heat into your 3 season porch through the floor of the deck using flexible ducts.  Is that right? 

I think you may need a permit for that at the very least.  It may be easier and cheaper for you to purchase electric baseboard heaters and hardwire them in.  That way you will also have thermostatic control of the temp in your 3 season room without relying on and compromising your main home temps. 

Of course I could have it all wrong. . .


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## Daryl in Nanoose (May 27, 2008)

I would use a wall space saver forced air heater. Like said you will have control over the temperature in there.


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## glennjanie (May 27, 2008)

Welcome Laplow:
If your house was built before 1970, then you probably have the capicity to handle the extra room. I would use galvanized metal pipe with fiberglass sleeve insulation to run the air to the room. It is smooth on the interior and allows the air to slip right on through, whereas the flex duct has a spiral wire through it and serves to slow the air down and wear it out. 
I have seen a 30' run of flex duct that would not move cigar smoke if held 1' in front of the wall register. I had the flex changed out for pipe and the same run would blow a candle out at 1' away from the register.
Glenn


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