Thinking about adding a auto damper


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Old 03-05-14, 11:04 AM
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Thinking about adding a auto damper

Hey all I was wondering if it worth adding a auto damper? Or if it's possible. My boil is a gas fire cast iron type. Has a piot that's always on, question really is can I add one to this system? When a piot always being on. The wire drawing has a plug in for one that's jumpered right now. Thanks all
 
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Old 03-05-14, 01:10 PM
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A standing pilot wouldn't prevent you from installing the damper. The damper has a microswitch which opens when the damper isn't open - inhibiting the gas valve from turning the main burner on.

I don't know if "it's worth it or not." I haven't seen any studies that show how much fuel they save, but they should help some. The only drawback is that it's an additional complication that might unnecessarily shutdown the boiler if the microswitch sticks open.
 

Last edited by gilmorrie; 03-05-14 at 03:19 PM.
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Old 03-05-14, 04:03 PM
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thanks for the replay. I wonder how much more efficiency I would get. would it justify the cost, maybe someone here would know.
 
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Old 03-05-14, 04:27 PM
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Installing a vent damper on a gas boiler that has a standing pilot would require a damper that had a hole in the damper plate to allow for the exit of the flue gases from the pilot. Not doing so would likely cause the gases to "spill" from the draft diverter assembly and THAT could introduce carbon monoxide into the boiler room. Since the purpose of the damper is to stop air flow through the boiler and from the room up the chimney adding a hole in the damper plate will to some degree lessen the effectiveness of the damper.

I would not install a damper under these conditions.
 
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Old 03-05-14, 04:55 PM
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Gosh, you really think that a little pilot light would build up dangerous CO in a properly vented boiler room? How about a gas range with a standing pilot and burners with no vent from the kitchen? Or other such indoor gas appliances?
 
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Old 03-05-14, 05:03 PM
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The Field GVD has the hole in the plate.

Gil, what is a 'properly vented boiler room' ? One with a window open?

One of the dangers of CO is the LONG TERM exposure to LOW LEVELS of CO. It causes CUMULATIVE damage over time.

I do see your point about the gas range though... but that's the only other indoor appliance that I can think of with a pilot that is not vented.

I don't know the 'tightness' of OP's home, but if I had one of those new modern homes, my range would have electronic ignition and a range hood.
 
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Old 03-05-14, 05:57 PM
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Gil, what is a 'properly vented boiler room' ? One with a window open?
No, that is a ridiculous comment. It depends upon the volumes of the boiler room, the adjacent spaces, and the cross-sectional area of the openings in between. NFPA 54 and other codes cover this, as do some other codes. If the boiler room has adequate ventilation and air intake for the main burner, it will certainly be adequate for a tiny pilot.
 
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Old 03-05-14, 06:05 PM
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I do see your point about the gas range though... but that's the only other indoor appliance that I can think of with a pilot that is not vented.
How about a stand-along gas oven? It's not just the tiny little pilot, its also the unvented main burners for a range or an oven. They could be running continuously for hours, and are many, many times the fuel input of a pilot. CO detectors are, of course, always advised - but they have never activated here.

My 60-year-old gas kitchen - should I rip it out and replace it with electric? I think not.
 
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Old 03-05-14, 06:10 PM
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No, that is a ridiculous comment.
Yes, I know, carefully crafted for just that reaction, and no more ridiculous than your comment about 'dangerous CO'. ALL CO is 'dangerous', no matter how small the source or level. Some days it's unhealthy to be OUTDOORS in some places.

My point was that it just simply doesn't make sense to ignore any source of CO into the home, no matter how small, when it is PREVENTABLE, and this is the reason for the hole in the damper plate.

How much radiation is acceptable?

How much arsenic is acceptable?

If there is any way to CONTROL exposure, then by all means seize control.
 
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Old 03-05-14, 06:11 PM
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I don't know the 'tightness' of OP's home, but if I had one of those new modern homes, my range would have electronic ignition and a range hood.
A good idea, but I'm unaware of any codes requiring that. What would you do with a built-in gas oven?

Would you instrument the range hood to run whenever a burner is on? How?
 
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Old 03-05-14, 06:15 PM
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From my understand that these dampers have about 5-8 percent open. So they are not 100 percent sealed when closed. Should be enough for a pilot I would think. Back to the original question. Is one worth worth putting in? Or just save my cash. Great discussion tho.
 
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Old 03-05-14, 06:23 PM
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If I had to 'ballpark' possible savings, I would take a SWAG at maybe 2% ... MAYBE ... the damper would probably require replacement before the purchase price and labor to install was covered by savings.

It's not only about keeping the heat in the boiler after a cycle, it's about the constant 'pressure differential' that the chimney draft causes in the home.

When the chimney is open with no damper, there is a CONSTANT draft up the chimney, pulling the air from the home, lowering the pressure in the home and causing a higher rate of air infiltration into the home.

With this in mind... maybe a bit more than 2%, but I can't recall ever seeing any savings claims from manufacturers or energy auditors.
 
 

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