Draft for gas equipment

ppac

Anyone have a chart that shows acceptable draft measurements for gas equipment

EBEBRATT-Ed

Depends on what type of appliance it is. there is no standard answer. Follow the MFG recommendations

ppac

I had an energy audit done and they said the boiler was drafting at .6 inches wc. The gas water heater is tied into the same vent befire it goes up the chimney. Its an old boiler and water heater.i didnt know if there was a chart of some kind ill try to see if i can find manufacturers recommendation online. Thanks

Bob Harper

I'm sure you meant -0.06 wci as .6 would be a vacuum cleaner. That's a bit high but it depends upon where they're testing, at what stage in the firing cycle, the weather, if this boiler has a draft hood, etc. All you really need is a neg. .02 wci. Anything above that tends to cut efficiency. High draft can cause CO spillage from 'curtain effect' at draft hoods.

GW

yes that's a bit high (neg .06"), is your basement leaky??
Older home?
What did the energy audit guy/girl tell you beside the number?

Tim McElwain

Need to see a picture of your installation along with all the readings taken during the audit. It sounds like you are suffering from what is called "Curtain Effect". Many times that can only be resolved with replacing the draft hood with a barometric. All that should be accomplished by a professional. Ask whoever you are going to hire if they have ever heard of "Curtain Effect" if they say no they never heard of it then do not hire them.