Direct Vent vs Power vent

**dtherrien** · 12-23-2011, 03:04 PM

I currently have a State 510E propane fired Hw heater. The date on
S it is 1991 and i purchased the house in 1996. Within the past couple of years i noticed soot around the burner area and the flame seems to have more yellow tips than it should. I have maintained the WH regularly....three times a year i drain and flush out and also pull the burner assembly and clean. Every couple years pull the vent baffle and clean.
I think it is time to replace the WH and am considering a direct vent or a power vent...i dont know the pros and cons of these type heaters.
I wont be using the atmospheric vent.....it snakes its way through the house to the roof( i have a ranch style house with a dutch style roof).
The new heater will be either a Bradford White or an AO Smith 50 gal. quick recovery.

**jadnashua** · 12-23-2011, 03:48 PM

This is how I understand the differences:

A direct vent uses either a concentric pipe or dual pipes to get external air and vent the combustion gasses. It needs to be closer to the exterior than a power vent.

A power vent uses a fan to push the exhaust gasses further than a direct vent. It gets combustion air from the inside, so it relies on air leaks to enable the burner to run.

Given a choice, I'd go with a direct vented unit - quieter in operation because it doesn't have the fan which can wear out and require replacement, plus, it can be noisy especially when it ages. Nasty if it's near a bedroom window.

**LLigetfa** · 12-23-2011, 04:01 PM

My former WH was a State direct vent that used outside combustion air and was silent. After 10 years it sprung a leak. I could not find another brand of passive direct vent that would line up with the existing hole in the wall so I went with a power vent. It is so noisy that I regret my decision and if I had my druthers, I would have patched the existing hole and cut a new one up higher.

As Jim said, a power vent uses indoor air which has to be replaced resulting in a cold draft through the make-up air vent on the furnace cold return duct.

**Chad Schloss** · 12-23-2011, 05:35 PM

we have two power vent heaters in two houses; one being a bradford-white, the other a rheem. they both make some noise, neither makes enough noise to hear from upstairs. the rheem is slightly louder. being right next to both of them while being on the phone can be annoying, but it isn't that bad... i can see sealed bearings in the motor ends, the motor should last the life of the tank.

**Gary Swart** · 12-23-2011, 10:05 PM

I have been using a power vent heater for over 15 years. On #2 now, I've had no problems with either one. First heat tank went south, and I replaced it with the current one. The heater is in the basement, so the sound is not a problem. I can see that if it was located closer to the living area, noise might be annoying. I have no experience with direct vent.

**dtherrien** · 12-24-2011, 07:43 AM

Thats what i wasnt sure of.....if a direct vent had a blower for the exhaust side. It must flow out naturally because of the hot exhaust? Has there ever been any known problems with a direct vent?
In 31 years of construction we have never had a direct vent WH installed on any job. The direct vent will probably be the direction i will go.
It will be going on an outside wall in the basement.

**LLigetfa** · 12-24-2011, 08:18 AM

Generally, if it has a blower it is called a power vent but there is no standardization of the terms "direct vent" or "power vent" so you need to look at the specs of each brand/model. What I can say, is my State direct vent used no blower and it drew the combustion air from outside. My current power vent uses a blower to exhaust out the side of the house via PVC pipe and it consumes indoor air.