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If I go with direct (atmospheric vent) 75gallon...what model would you recommend? Are there ones that recover a lot faster and could provide hot water faster than others?


I'm pretty sure atmospheric 75 gallon heaters are no longer available?
 
Yeah I think anything over 50 gallon now has to be direct vent
 
Yeah if you run the PVC pipe all the way down your chimney the point of a direct vent besides being more efficient was to eliminate the need for a chimney
 
on your vent, a 90 is a 90 degree offset.

in the literature that comes with the unit. they will tell you, you can offset "X" amount of degrees

you can not go over that. last unit I installed was allowed 180 degrees in offsets

that is 2, 90 degree turns. and 3' total horizontal run
 
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Yeah if you run the PVC pipe all the way down your chimney the point of a direct vent besides being more efficient was to eliminate the need for a chimney

Direct vent DOES NOT USE PVC OR EXISTING CHIMNEY
 
Direct vent DOES NOT USE PVC OR EXISTING CHIMNEY

My inspection revealed a high efficiency water heater with purple/brownish PVC pipes and yellowish PVC flue pipe fittings. The flue pipes were obviously deformed from heat, and they were sagging. A maintenance man for the university said that some really bad pipes had come apart at the fittings and melted. This set off the carbon monoxide alarm and prompted a maintenance call. The water heater had scaled up due to minerals in the water supply; this caused the flue gas temperatures to rise, which created the noted problems.

The pipe was Schedule 40 PVC pipe. Although the water heater installation manual we obtained recommended using PVC pipe as a flue material, PVC pipe manufacturers do not recommend this. I called the manufacturer of the PVC pipe in this case and asked the representative a few questions about using PVC pipe as a combustion flue for fuel gases. He was quite familiar with this issue and emailed me a link to the company’s technical manual, which discussed all of the physical and temperature limitations of the piping.

He said that the company has had numerous complaints about PVC pipes used for venting flue gases, and that they always point out that they do not recommend this usage and that there is no listing for it in their manual. He has asked every major manufacturer of boilers and water heaters for data to support the recommendations in their literature for the use of PVC pipe for combustion flue materials but has not received any replies.

This is concerning to me. Just because a manufacturer recommends using PVC does not mean that it is acceptable or safe. Just because PVC works in new installations does not mean that a condition cannot occur in which scale builds up over a short time in hard water areas and causes high flue gas temperatures. Most boiler and water heater manufacturers list other ways of venting with stainless steel, but they seem to always recommend the cheapest way in their literature, in an attempt to make the boiler seem more affordable to consumers.

EXCERPT SOURCE-http://plumbingengineer.com/content/pvc-acceptable-vent-material-flue-gases
 
Bradford and State both still have an atmospheric 75

Direct Vent or Atmospheric Vent units would have relatively the same efficiency? The difference is that they just vent differently? The current tank vents out the chimney. My thought was to replace it with an atmospheric tank that would vent out the chimney as well. I might have to have the chimney lined, but I would prefer that since I would not have to have another hole in the house.

However, if a direct vent tank would be more efficient, I would go with that and have the hole created for a direct vent.
 
Direct Vent or Atmospheric Vent units would have relatively the same efficiency? The difference is that they just vent differently? The current tank vents out the chimney. My thought was to replace it with an atmospheric tank that would vent out the chimney as well. I might have to have the chimney lined, but I would prefer that since I would not have to have another hole in the house.

However, if a direct vent tank would be more efficient, I would go with that and have the hole created for a direct vent.

A direct vent uses outside air vs conditioned air for combustion that is how they gain efficiency.
 
So please inform me what materials you use to vent.
So I'm just going to think that all the manufacturers of the water heaters who send PVC fittings with the the water heater are clueless and not to even mention high efficiency furnaces that use PVC for flue

And you can reuse the existing chimney as long as the pipe is brought down through the chimney and then connected to the water heater.
 
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So please inform me what materials you use to vent.
So I'm just going to think that all the manufacturers of the water heaters who send PVC fittings with the the water heater are clueless and not to even mention high efficiency furnaces that use PVC for flue

And you can reuse the existing chimney as long as the pipe is brought down through the chimney and then connected to the water heater.

Power vent heaters use PVC typically. Direct vent uses metal venting
 
My mistake I interchanged power vent with direct vent.

When I refer to a water heater that vents out a chimney I call it atmospheric vented
 
So I'm just going to think that all the manufacturers of the water heaters who send PVC fittings with the the water heater are clueless and not to even mention high efficiency furnaces that use PVC for flue

:(

Did you bother to read the TECH ARTICLE I posted above?

The pipe was Schedule 40 PVC pipe. Although the water heater installation manual we obtained recommended using PVC pipe as a flue material, PVC pipe manufacturers do not recommend this. I called the manufacturer of the PVC pipe in this case and asked the representative a few questions about using PVC pipe as a combustion flue for fuel gases. He was quite familiar with this issue and emailed me a link to the company’s technical manual, which discussed all of the physical and temperature limitations of the piping.

He said that the company has had numerous complaints about PVC pipes used for venting flue gases, and that they always point out that they do not recommend this usage and that there is no listing for it in their manual. He has asked every major manufacturer of boilers and water heaters for data to support the recommendations in their literature for the use of PVC pipe for combustion flue materials but has not received any replies.

You want SS Double Wall B-Vent.

Hopefully ( :rolleyes: ), the contractor you choose will be licensed and insured, ethical and pull a permit on the installation.

Vent- Direct vs Power.jpg

Vent- Double Wall (B-Vent) & Single Wall.jpg
 
I pray that you have a reputable company to come do this. Direct vent is metal that comes up and out the side of the house. Made with specialized venting that comes with the water heater. Atmospheric venting will get hot and needs to be b-vent style pipe up and out the roof. Power vent and power direct vent uses pvc. It's up to you to read up on the efficiencies.
 

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