The Conservative Cave
Current Events => The DUmpster => Topic started by: franksolich on December 11, 2011, 02:39:02 PM
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http://www.democraticunderground.com/115827
Oh my.
pipoman (6,968 posts) Profile Journal Send DU Mail
Venting a Water Heater
Has anyone here vented a standard tank type water heater through a wall rather than through the roof?
I posted a thread on DU2 some time ago about our new basement and moving our house. We have been venting through a window hole in the new basement temporarily. Now I am getting ready to permanently place the water heater in the utility room in the basement. We bought a 95% furnace which vents through PVC through the rim joist. I would like to vent the water heater through the rim joist as well. I am not subject to inspection or code, but certainly want my work to be safe. I have seen vent blowers but wonder if the fan runs all the time wasting energy, or if it only runs when the heater is firing. My plan was to vent using double wall stove pipe.
Any suggestions would be appreciated.
Tesha (18,915 posts) Profile Journal Send DU Mail
1. You shouldn't do it; they depend on the Chimney Effect for their draft.
Only power-vented water heaters should be vented through a side wall.
pipoman (6,968 posts) Profile Journal Send DU Mail
3. My thinking is that for the cost of a power vented
tank type heater, I would be better off buying a tankless 95% heater. I intend to do that in a couple of years, my old heater is only 2 years old, and I think the tankless will be better and cheaper in a couple of years. I had the gas company install a high capacity regulator and plumbed my gas with 1" pipe in anticipation of this.
I wouldn't just vent through the rim joist without a vent fan. I wasn't very clear in my OP...but my question really is about use of external vent fans like this one..
http://www.menards.com/main/water-heaters/parts-accessories/bosch-aq4-power-vent-for-horizontal-venting-of-models-1600p-1600h/p-200839.htm
Tesha (18,915 posts) Profile Journal Send DU Mail
5. One caution with a tankless:
We had to replace our old power-vented tank heater two years ago. We decided to go with a tankless primarily for three reasons:
1. Greeness
2. No floor space required in an area of the house where space was at a premium.
3. Better reliability and longer life with what we perceived as less flooding potential down the road.
Mr. Tesha wanted a Bosch but the installer and I talked him into a Rinnai. Now, he's *VERY* unhappy with that choice because, while the Rinnai is great at delivering huge gouts of hot water, it frankly *SUCKS* at delivering small amounts of hot water.
We have low-flow shower heads everywhere in the house and a relatively low-flow kitchen faucet and
the Rinnai routinely switches off when those appliances are drawing hot water. This is especially true in times
when the water pressure is low or you've tempered the water towards "warm" rather than 100% hot.
So Mr. Tesha has taken more cold showers with the Rinnai than he ever took with the tanked heater.
The same thing happens with our dishwasher: if we work hard to get hot water to the kitchen, the dishwasher
can draw hot water for its first cycle, but after that, it runs on cold water (with predictably lousy results).
His perception, fair or not, was that the Bosch could correctly throttle itself down to lower volumes of water
than can the Rinnai.
So the bottom line is: don't be swayed by the promise of how much hot water the instantaneous heater can
deliver; instead, be swayed by promises of how low it can go while still heating water.
BTW, wanna buy a slightly-used Rinnai?
pipoman (6,968 posts) Profile Journal Send DU Mail
6. Thanks for the tip
I read something about this a while back. This is part of my reason for wanting to use my old heater for a couple more years in addition to tankless coming down, I suspect some of these bugs will be worked out. Are you sure you have enough gas volume for the unit? The tech from the gas company said that some people who have installed these type heaters ave experienced problems because it demands more gas. If the volume isn't high enough the heater will shut down.
He said since this has been discovered he has installed many increased capacity regulators on existing meters and the home owners have had to re plumb their gas lines. He said some installers were using a reducer coupling to convert the existing 1/2" gas line to 3/4" which also choked the new heater...if you haven't already, it might be worth investigating.
Tesha (18,915 posts) Profile Journal Send DU Mail
7. Oh yeah, we have enough gas.
It's got its own very short, dedicated 1" line direct from the meter. This is clearly very important: the Rinnai is the heaviest gas load in our house, topping even the central heat.
And again, the problem isn't high-volume use*, it's low-volume use: the Rinnai simply can't throttle itself
down far enough. Instead, it says "too little water flow; switching 'off'."
* Last winter, when our roof became a huge iceberg, we cleared the ice by running a garden hose from the laundry sink to the roof and using hot water to "de-adhere" the ice. Even supplying that continuous,
heavy load, the Rinnai never faltered. It's great at heavy loads, it only sucks at light loads.
OffWithTheirHeads (7,004 posts) Profile Journal Send DU Mail
2. Please don't do this. If done improperly this CAN KILL YOU!
Believe it or not, most building codes were developed for a reason and venting gas appliances are high on the list. If you don't know what you are doing and why, please spend a few dollars and let a trained professional do this for you. If you can afford a 99% furnace, you can afford to have this done correctly. You are correct with the double wall pipe (type B gas vent) but if you don't understand the codes as to clearances from windows, the roofline, etc. you are asking for trouble.
At least take the time to study the documentation that should have come with the water heater. By the way, the cost of the correct equipment for power venting is EXPEN$IVE! It will cost you less to hire a pro to install the gas vent properly than to buy the power venting equipment.
Trust me, I spent 43 years of my life doing this stuff.
Wether you get an inspection or not is irrelevent but if you are not experienced with the installation of type B gas vent, the time and money and frustration you will encounter will not be worth what you think you are saveing.
If you need more info, pm me. I don't want to read here about a DUer who died of carbon monoxide poisening.
pipoman (6,968 posts) Profile Journal Send DU Mail
4. Thanks
I certainly want it to be safe. The utility room is directly below an addition to the existing structure which we are currently building. I can install the vent through the roof and can get the code specs to be sure it is properly placed. I was trying to eliminate a hole in my roof now which would later be unnecessary. We are into this project for around $60k now and will be better able to afford an upgrade in a few years.
I appreciate your input, and the cost of doing this probably is prohibitive. Maybe I'll pony up for a heater designed to vent horizontally now, even though I feel I could save some money by waiting a few years..
Again, thanks for your expert input. I have been fortunate to find many pros like yourself both locally and online to help me with questions during this project.