vent advice for water heater


  #1  
Old 10-20-04, 02:23 PM
culicans
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vent advice for water heater

We are in the process of buying a new (old) house. The chimney stack is being used only to vent the gas water heater. The furnace is high efficiency and vents directly out the wall. We would like to replace the water heater with one that does not need to vent out the chimney, as we would like to have the fireplace updated and replace the small chimney with a larger one in the same place. Our inspector said to buy a "low vent" version with PVC pipe exhaust to the outdoors (like the furnace). What do you recommend and are there any obvious pitfalls you can point out that I can try to avoid?
 
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Old 10-20-04, 02:44 PM
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Never heard of a low vent. What I think he meant was a "power vent". No experience with them but know they are more costly than the "regular" heaters. Check out price differences to see how much more. Good luck on your projects.
 
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Old 10-21-04, 03:28 PM
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Hello: culicans. Welcome to the Do It Yourself Web Site.

If the existing water heaters venting could be altered or modified to maintain a constant vertical rise, than it is or may be possible to vent the existing water heater directly to the outside.

Non power vented water heaters must maintain a vent pipe with a constant vertical incline and no 90 degree angles or elbows used. If the ceiling above the water heater is clear and you are able to vent the heater directly upwards to the outside, do so.

Alter or modify the existing venting system to meet the above and or local codes. Angle vent pipe joints are available to alter the vent pipe angles, if needed and in case the area directly above is not clear. An area nearby above the water heater can be used, if there is any.

Not enough specific infor on the location of the tank is and or area the water heater is located in. Basement? Attic??? Closet? Garage?...???

Kindly use the reply button to add the additional information. Using this method moves the topic back up to the top of the list of questions automatically. No need to post a new question.
 
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Old 10-23-04, 04:12 PM
culicans
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The water heater is in the basement, in a corner, next to the furnace. I think it would be difficult to achieve the steady rise with no angles in the present location. The heater is from 1987 so putting in a new one is not unreasonable as it seems to have lived a useful life, but I need to know which one. My father suggested just getting an electric water heater to avoid the whole venting issue, but I seem to remember changing the heating coil on a regular basis on one we had growing up (well water with lots of lime sediment). My gut tells me to stick with gas. Your thoughts?
 
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Old 10-23-04, 05:02 PM
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Hello; culicans

If not other options are available, the vent cannot be sightly angled without 90 degree elbows, than seems like the only option would be to buy and install a power vented water heater.

Like majakdragon mentioned, T too have never heard of a low vent water heater. I too, like him, suspect you mean and or the person who told you meant a power venting/power vented water heater.

Those types have a double walled venting system. One large diameter vent pipe with two seperate vents included into one system. Same as a through the wall vented heater. Except the water heater has a power fan to vent the fumes and draw in the air as the power vent removes the fumes.

A power vented water heater would than need an electrical supply nearby or one brought to the location or however the code determines the power be supplied to the appliance. Codes vary. Check with the codes office.

Power vented water heaters come in different models. Be sure to buy the one best suited for the application, codes and water capacity to meet the needs, etc.
 
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Old 11-19-04, 04:13 PM
olly
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a related set of questions

Having looked at this thread I have a similar issue. I have a standard venting water heater that currently vents from its location in the garage up through a closet in a bedroom on the floor above and out the roof. I would like to free up space in the closet and vent up the outside of the house instead. In addition to this reason, the current venting configuration in the garage is suspect - it makes a right angle less than a foot above the draft hood, travels more than 6 feet horizontally (actually at a slight incline) and then turns about 90 degrees upwards to vertical and up through the house. Given that the water heater is next to the side wall, it seems to me to make sense to exit the house just above the draft hood and go up the outside wall to about a foot above the roofline (about 12 foot vertical travel). Here are my questions:
1: Should I NOT do this for some reason, and why?
2: Should I use Type B, double walled venting on the outside or single wall?
3: Are there condensation issues and what measures can I take to prevent them?
4: The draft hood reduces to 3 inch diameter. Should I connect double wall tube to it and exit the wall using the double wall or is single wall 3" sufficient (wall is made of wood shear and stucco)?
5: From Sharp Advice's remarks I would conclude that I should try and use two 45 degree bends to get from the draft hood to the exterior vertical vent (instead of two 90 degree bends). Correct?
Thanks in anticipation of your advice.
 
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Old 11-19-04, 10:10 PM
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Single wall dust is often used on water heaters.. You must observe the rules.
For single wall duct, the minimum clearance to combustible material ( which includes drywall) is 6 inches. So we often use B-vent fittings for roof and wall penetrations. B-vent has 1" minimum clearance.
 
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Old 11-21-04, 02:19 PM
rheem
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i'm no pro

I can say only from my own experience that if you do install a power vent then make sure the exhaust is not put in a place that could annoy people as the exhaust is somewhat noxious. Also beyond about 5' from the heater the exhaust should be angled slightly outwards so that condensed exhaust water doesn't run back onto your motot unit. I prefer the non power vented models because they seem to be less prone to breakdown and don't require electricity.
 
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Old 11-21-04, 02:45 PM
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OLLY You dont say what kind of wall there. Check code there first for sure. Id use B vent out the wall and up to the top of the roof. Is that 12' the ridge of the roof? Dont forget on the wall there if it is wood you have to keep the B-vent 1" away from it. Then just sheet metal pipe from the heater to the B vent in the wall slope it up just a little/
Id also check code there for that water heater in the garage. Gas flame here has to be 2' up off the floor in a garage.

ED
 
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Old 11-22-04, 08:16 AM
olly
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Thanks 594tough and Ed Imeduc

The plan is coming together now. By the way, my wall is made of stucco and the roof has a very shallow pitch (eg less than 5 degrees), so I was saying 1 foot above the roofline at the point the vent reaches it as opposed to 1 foot above the ridge. The water heater is 18 inches off the ground according to code.

It looks like I'll penetrate the wall (currently just stucco - need to add sheer wall on the inside asap) with double wall B-vent and continue up the outside wall with same even though wall is stucco.
 
 

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