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Thread: Attic ductwork
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12-26-2012, 08:46 AM #1
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Attic ductwork
Hi: I'm trying to size a new upflow heater to existing non insulated sheetmetal system in attic. The old heater was removed from storm Sandy. I used a online calulater and got 49000 BTUS. There was no consideration for attic ductwork.
Its only a 1000sf house and owner does'nt want to insulate ducts. Anyone know the addition heat loss from above ducts.
thanks...
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12-27-2012, 09:39 AM #2
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As much as 70% loss/gain, especially if its the return duct. Don't forget the ducts will sweat in hot attic this summer time.
As iron sharpens iron so one man sharpens another Proverbs 27:17 NIV84
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12-29-2012, 10:08 AM #3
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Are you sure the duct work in the attic isn't insulated. it my be that its just the sheet metal in the utility room isn't insulated.
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12-30-2012, 12:36 AM #4
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The owner may not want the duct insulated but that makes him wrong as you would be if you do the install that way.
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12-30-2012, 12:51 AM #5
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might want to check your local codes . ductwork run in an unconditioned space isnt up to code around here.
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12-30-2012, 01:02 AM #6
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If he doesn't want to insulate, then he better be spray foaming the roof line.
Originally Posted by deadeye52
Otherwise you have a lawsuit when the drywall repair/mold abatement issues come about."Better tell the sandman to stay away, because we're gonna be workin on this one all night."
"Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."
"Just get it done son."
Dad adjusted
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12-30-2012, 08:25 PM #7
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I'd turn the job down if he doesn't want to do it right. Do you really want to oversize the furnace to accommodate uninsulated ductwork?
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01-01-2013, 10:40 PM #8
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sounds like the owner is not understanding why ducts are insulated.
do you really want to do a job where occupants will never be comfortable?
high utility bills, dripping ducts & no comfort?
there will be alot of call backs on this kind of job.
have to agree with ron:
The owner may not want the duct insulated but that makes him wrong as you would be if you do the install that way.
I'd walk away if I couldn't get the homeowner to understand.
are you sure the duct isn't internally insulated??
best of luck.The cure of the part should not be attempted without the cure of the whole. ~Plato
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