Best natural gas water heater for inside a home’s envelope?
Climate – 5a
Air-sealed R32 walls.
My clients are looking for the best 50 gal. natural gas water heater for the home we’re building them.
We had planned to have an un-powered direct-vent heater in the basement mech. room which has one framed wall in the daylight basement side. It would cost about $1650 installed. (Bradford White RG2DV50S6N) Pro is that the power and gas are already in-place. Cons of this arrangement are the costly unit vs. efficiency and the proprietary vent which will be exiting through a stucco clad daylight basement wall. When the unit needs to be replaced the vent will almost certainly need to be replaced as well since they are product specific.
They are now considering a 50 gal. high-efficiency condensing unit in the same location. What would your product recommendation be if they went this direction? I haven’t even seen one that does not incorporate a powered vent of some sort.
Pros should be efficiency – at least $175/yr savings in energy.
Cons of this arrangement could be the up-front cost. They need to keep the unit cost to $2300 or less to make sense to them.
Alternatively, they are considering a traditional atmospherically-vented model in the garage. The 1st-floor garage is located directly above the mech. room and has a pre-stressed concrete floor.
Cons of this arrangement are additional 8′ of gas pipe and electrical as well as that the tank location requires about 16-20′ of double-wall venting pipe and a tank stand. Installed cost would be $1500 plus the gas and water re-routing.
I’d love to hear your feedback.
Cheers,
-Nethaniel
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Replies
By far the very best high efficiency water heater available today , and below the customers price point for unit cost . This one is modulating and condensing .
http://www.htproducts.com/phoenixldwaterheater.html
Why do you need electric for an atmospheric vented water heater ? Water pipe in a garage is not a good idea , heater would have to be raised in most jurisdictions .
Netheniel,
In your climate zone (Zone 5), you don't want to put a water heater in a garage. The chance that your plumbing pipes will freeze is too high.
I think that your reasons for not using the Bradford White RG2DV50S6N water heater don't make much sense. You're worried about changing the vent termination in 10 or 14 years when the water heater conks out? Replacing the vent termination is trivial. If you want to plan for different eventualities, just install a large pressure-treated mounting block -- perhaps a 14-inch-long piece of PT 2x10 -- mounted on the exterior wall. The vent termination goes through the center of the mounting block. The mounting block is flashed carefully, with the flashing integrated with the WRB. The entire exterior of the mounting block is trimmed with painted metal flashing so that it looks good.
Then, in 14 years, you can install any type of vent termination on the mounting block you want, with minimal flashing changes.
+1 on the HTP Phoenix Light Duty recommendation. The stainless tank will outlast a glass lined B-W direct vent by 2x or more, and the first-hour gallons performance is higher more than 1.5x.
If the mechanical room houses condensing gas furnace, it may be better from a fuel use perspective to use the Phones L.D. + hydro-air air handler. If it houses a gas fired boiler, an indirect fired hot water tank operating as a zone off the boiler makes more sense.
Good recommendations by Dana . Phoenix LD will do a hell of a job w/ hydro fan coil . Hydronic heating can also be achieved although not shown in the manual for the following reason .
http://www.proudgreenhome.com/videos/ibs-warmboard-radiant-heating-systems-introduces-heat-source-that-is-as-easy-to-install-as-a-water-heater/
The unit can do both heating and DHW .
I installed the HTP Phoenix LD in my home a little over a year ago and have been extremely happy with the performance.