Don't see this much

[71CHOPS]

hey, that's cool! you can stick a power burner on ANYTHING!!!!LOLOL!!

never seen one.....but we don't have much oil down here.

[philjafo]

A draft hood (or gap as you put it) serves a completely different purpose than a barometric. According to ASHRAE a draft hood isolates the appliance from the flue allowing combustion to take place without venting action. Since it disconnects the appliance, draft and air through the burner is completely uncontrolled. Draft hoods are designed for a specific set of conditions, which are; a vent of not more than 5 ft in height with 1 or 2 elbows. How often do those conditions get met in the field???

A barometric or draft regulator on the other hand allows for a consistent amount of air through the burner that does not change with changing conditions. Those of us who test for CO find draft hoods spilling quite often, either with higher than normal or lower than normal flue draft pressure. They are not safe under all conditions! A draft regulator is the only way to fix them. A spill switch added to the bottom of a double swing barometric will shut down the burner if the flue gets blocked.

So your saying a 30 foot horizontal run is no good for a water heater
Good point though on tje differnce between draft hood and barometric damper, ones powered and the others just natural drafted. Two totally different animals.

[chuckcrj]

So your saying a 30 foot horizontal run is no good for a water heater
Good point though on tje differnce between draft hood and barometric damper, ones powered and the others just natural drafted. Two totally different animals.

Even natural drafted appliances work far better with a barometric than with a draft hood.

[philjafo]

I'll admit I'm kinda new I've only been an HVAC tech for 5 years, while I've worked on a lot of oil burners (only a couple oil water heaters though) and always have a barometric on oil burners. But never never even heard of one on a natural gas natural draft water heater. Would it help on that has a vent that should work well but doesn't, for example one 90 elbow and say 3 ft horizontal then into an flex aluminum chimney liner, say 2 story house?

[pctech]

might not have been code when it was installed in my area its grandfatherd untill you replace the line tank or valves

[mattt787]

that we do

[mattt787]

so if you have a gas water heater and you have a long flue run take off the natural draft hood and put on a barometric damper would be best i i thought that was so wind would not come down and blow out your pilot

[pacnw]

So your saying a 30 foot horizontal run is no good for a water heater
Good point though on tje differnce between draft hood and barometric damper, ones powered and the others just natural drafted. Two totally different animals.

what?

both are natural draft!!

barometric damper has not fan/power.

I service 4 or 5 of these on maintenance policies. never had to clean one, but they probably should be done.

[philjafo]

Oil fired applications are powered combustion (the only thing I have ever seen a barometric damper on) they use a fan to force combustion, natural draft uses the heat from combustion to move air through (has a draft hood).

If your servicing 4 or 5 oil fired water heaters and not cleaning them, what are your customers paying for the maintenance for? Isn't cleaning part of the service for an oil burner, if not I've been doing wrong all this time.