Inside or outside intake vent?
New construction with ERV. Gigantic utility room has two 97% DV gas furnaces & a 97% gas tankless water heater. The two furnaces get their intake air from outside. The water heater gets it’s air from inside the room. I questioned it and the plumber said the room was so big, it was fine.
I’ve got two opinions. One says while there is sufficient air to prevent any backdrafting, I’ll have negative pressure drawing air in though envelope leaks.
The other opinion is the negative pressure will be so minimal (maybe a bit while showering), that’s it’s nothing to worry about. Adding the outside intake would also add another penetration to the envelope. And, I have an ERV.
The plumbers will be there tomorrow anyway for something else, should I have them change the intake? Thanks.
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