Dampers in Ductwork...Question??

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  #1  
Old 02-07-11, 08:14 PM
J
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Dampers in Ductwork...Question??

Hi,

I have a forced hot air heating system with an oil burner. My home is about 2300 sq ft and about 10 years old. My house is 2 floors and only one zone. My house always seems cold. We keep the t-stat at about 70.

I noticed today when I was in the basement that all the duct work going from the main trunk to the registers have dampers. Many of these dampers were closed or partially closed. I want to remove them completely since I dont think I will ever need to turn off an individual register (plus the dampers are not that easy to get to).

Is there any reason why I should not take them out?? I was just going to take them all out and seal the connection between the duct to the registers and the main trunk with mastic and foil tape.

I figure since many of these dampers were closed or partially closed, that is why it never really feels warm...

Thanks!!
 
  #2  
Old 02-07-11, 08:37 PM
B
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I would leave them in place and do some thinking about how to adjust them properly. I agree the ones that are closed is an indication someone messed with them without knowing what they were doing, but they are beneficial.

Assume they were all removed. One, you could have too much air flow for your heat exchanger and cause your fan to cycle on and off as your furnace struggles to keep up. Or, you could end up with too much heat in one area and not enough in another. So, you can have a HVAC tech come in with flow gauges and adjust your system for the proper distribution, or give it a try yourself. I'm not an HVAC guy, but there are some good ones on the forum.

As an additional note, the best way to make your house more comfortable is to reduce its heat loss. But that's another project.

Bud
 
  #3  
Old 02-07-11, 08:44 PM
J
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Ya, before I posted this thread I had already started removing them, I think I took out about 4. They are easy enough to put back though. I definately want to seal up the connections between the duct work properly, the previous owner used duct tape I have done what I can to reduce my heat loss, I blew in additional attic insulation, caulked all the windows, added weatherstripping to the windows and replaced my front door. I havent really had any huge improvement.

I kind of wonder why I had dampers at some of the ducts?? Other sections that go from the main trunk are behind the drywall ceiling in my garage, what if those have damers that are closed
 

Last edited by stickshift; 02-08-11 at 11:22 AM. Reason: removed quoting of entire post
  #4  
Old 02-08-11, 03:07 AM
B
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Dampers are supposed to be accessible. If someone has buried one and it is closed, you should be able to detect that by testing the air flow. Simple hand test will tell.

Your list of energy improvements is typical and your results agree. Although all of the items you listed are necessary, they may not be the ones you are looking for. Air sealing is a comprehensive search throughout the house for every hole the builder created during construction. Some foam or caulk (fire rated is best) and some flashing for the larger openings.

The list is extensive, but usually yields good results. Sealing those air ducts as you mentioned is a big one. I'll attach a link from Efficiency Vermont that does a great job of explaining air leakage. A bit slow to open but good.

Bud

http://www.efficiencyvermont.com/ste...ide_062507.pdf
 
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Old 02-08-11, 10:53 AM
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Thanks for the info...

Im thinking of sticking a snake down the ducts that connect in the garage to make sure there are no dampers...or maybe ill rent an inspection camera...Just seems like im not getting alot of air to the half of the house that is above the garage...
 
  #6  
Old 02-09-11, 11:13 AM
B
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Living spaces over a cold garage are often a problem and often a result of poor insulation in the garage ceiling. Since you ducts may be passing through that same space it may be a combination of heat loss and low air flow. Measure the air temperature in the ducts headed out to the garage and the air temperature in the supply register in each room. Any reduction in temperature would indicate heat lost in that ceiling.

Bud
 
  #7  
Old 02-09-11, 04:44 PM
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The ductwork in my garage runs through a bulkhead that has little to no insulation. Is there a way to add insulation without taking down the drywall? I was thinking blown in cellulose or someyhing, but I would think I would need some sort of vapor barrier between the ducts and the insulation...right?
 
  #8  
Old 02-09-11, 05:43 PM
B
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One of the reasons to pull down the drywall to get to those ducts will be to be sure they are air sealed. Once sealed, then everything can be filled with insulation. Since moisture can't pass through sheet metal, you already have a VB. You may also get a good look at what was installed for insulation in that ceiling. Typically it needs more.

Depending upon what/where the insulation is, cellulose may work.

Bud
 
 

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