Replace powered vent hot water heater w/ direct powered vent

[Renmtpdb]

Looking for advice. I’m replacing 2x 40 gal hot water heaters. Both are powered vent exhaust drawing room air for combustion. They are not in a confined space. Big basement with lots of room.

Lowes delivered 2x 40 gal AO Smith with powered direct vent. This style is designed to draw supply air from the outside. Question, the current powered vent draws inside air. So do both of my HVAC units. Is there any reason why powered direct vent can’t use ambient air??

 

[Reach4]

The advantages to drawing air from the outside include that drawing air from the inside will cause cold or hot air to infiltrate into the house to make up for the air removed from the basement. If you draw extra air in during the winter, you lose heat and humidty both. In the summer, you would bring in air and humidity.

But to address your question, I don't know.

 

[Sponsor]

 

[Renmtpdb]

Thanks Reach. I connected with AO Smith and they advised against replacing a powered vent with direct powered vent. They claim the unit is “balanced for outside ambient air”. Still confused why inside ambient won’t work other than effecting the efficiency rating. Anyway, gonna follow their recommendation.

 

[Fitter30]

Thanks Reach. I connected with AO Smith and they advised against replacing a powered vent with direct powered vent. They claim the unit is “balanced for outside ambient air”. Still confused why inside ambient won’t work other than effecting the efficiency rating. Anyway, gonna follow their recommendation.

Like any of the condensing water heaters most want the supply and exhaust the same side of the house for a even pressure.