Tankless in an unconditioned NJ attic

[Noth Jersey]

Folks,

Has anyone performed a tankless attic install in the Tri-state area? I currently have a commercial Rheem indoor tankless unit. One of the call center folks, after consulting with a tech for like five minutes, told me the freeze protection mechanism should make the attic install a viable option. Despite what the call center says, I'm under the impression that the freeze protection mechanism is a measure of last resort. I'm not sure it's made to operate on a continuous basis from late December through early March. My goal is to have no water heater in my basement. I'm not interested in saving the planet by consuming less energy or something. My CFLs are supposed to do that. What is a good solution to protect the Rheem unit from freezing temperatures?

Thanks,

Ben

[Ladiesman271]

The solution is not to expose the unit to freezing temperatures.

Read the manual. Everything is explained in it.

[Noth Jersey]

Right, but do you have any experience expanding a home's envelope to encompass the portion of the attic with the water heater without compromising architectural appeal of a home, e.g., building an enclosure in the attic with a louvered vent to the living space?

[Noth Jersey]

I really wish I had another "r" in my handle

[gregsauls]

Folks,

Has anyone performed a tankless attic install in the Tri-state area? I currently have a commercial Rheem indoor tankless unit. One of the call center folks, after consulting with a tech for like five minutes, told me the freeze protection mechanism should make the attic install a viable option. Despite what the call center says, I'm under the impression that the freeze protection mechanism is a measure of last resort. I'm not sure it's made to operate on a continuous basis from late December through early March. My goal is to have no water heater in my basement. I'm not interested in saving the planet by consuming less energy or something. My CFLs are supposed to do that. What is a good solution to protect the Rheem unit from freezing temperatures?

Thanks,

Ben

I'm not familiar with the Rheem units, but other brands do have models that are "externally" mountable and as such their freeze protection is 1st line defense. I would follow Rheem's suggestions.

[Noth Jersey]

I'm not sure the call center folks really know. "We haven't ever heard of any problems with an attic installation." and "I'm not really sure what would happen if the heater were exposed to freezing temperatures." Anyway, I'm not sure that my house is large enough at this point to internally supply the needed volume of air for combustion specified in the manual:

A confined space is one having a volume
of less than 50 cubic feet (1.4 m3) per
1000 Btuh (0.3 kw) of the aggregate input
of all appliances within that space.

My main floor is 22x29 with eight-foot ceilings and the walkout basement on the same footprint has 7 foot ceilings. That puts me very close to the 10,000 cubic feet required to feed this baby. That's assuming that all my rooms are communicated with sufficiently large vents. So my house is on the threshold of being a "confined space."

[jimbo]

I think the units that are outdoor rated, but you still have to protect the pipes.

It would be a simple matter to open a vent through the ceiling, and create a small "room" above, for the WH. But I think the heating cost to do so would be large.

[Noth Jersey]

I think the units that are outdoor rated, but you still have to protect the pipes.

It would be a simple matter to open a vent through the ceiling, and create a small "room" above, for the WH. But I think the heating cost to do so would be large.

It's an indoor model, but I think that has to do more with the absence of a vent than its resistance to freezing. The manual says both the outdoor and indoor units need to be protected from freezing. I planned on foam insulation for the pipes. If I go the enclosure route, the box would be very well insulated. What's your thought on the combustion issue? Do I need to worry about having 10,000 continuous cubic feet of space? If you have eight-foot ceilings, that's 1250 square feet that must be open. I mean, I don't have to remove all the doors in my house, do I? Beads are pretty cool, but my wife likes a solid door on the bathroom for some reason.

[CT]

It's an indoor model, but I think that has to do more with the absence of a vent than its resistance to freezing. The manual says both the outdoor and indoor units need to be protected from freezing. I planned on foam insulation for the pipes. If I go the enclosure route, the box would be very well insulated. What's your thought on the combustion issue? Do I need to worry about having 10,000 continuous cubic feet of space? If you have eight-foot ceilings, that's 1250 square feet that most be open. I mean, I don't have to remove all the doors in my house, do I? Beads are pretty cool, but my wife likes a solid door on the bathroom for some reason.

Get a direct vent tankless water heater and you don't have to worry about having enough combustion air from the room. With direct vent, all combustion air is taken from outside. If you don't want to use direct vent, and you are in a confined space, then you will have to provide 2 openings to the space that the water heater is located. I'm in California, so I'm not sure what your code says in New Jersey.

[gardner]

A leak in your basement is one thing. A leak in your attic is something totally different. Why tempt fate? The internal freeze protection is electric -- a 4 hour power outage could destroy your home. And the freeze protection does not protect the plumbing, so you have to figure out how to protect that separately.

[Noth Jersey]

A leak in your basement is one thing. A leak in your attic is something totally different. Why tempt fate? The internal freeze protection is electric -- a 4 hour power outage could destroy your home. And the freeze protection does not protect the plumbing, so you have to figure out how to protect that separately.

Yeah, the enclosure thing sounds like the way to go. I'll have vent issues if I try to locate the water heater next to the well pump in the basement utility room (windows, porches, sidewalks, and doors). The existing water heater is right in the middle of the space where my dedicated home theater is being built.

[Noth Jersey]

Get a direct vent tankless water heater and you don't have to worry about having enough combustion air from the room. With direct vent, all combustion air is taken from outside. If you don't want to use direct vent, and you are in a confined space, then you will have to provide 2 openings to the space that the water heater is located. I'm in California, so I'm not sure what your code says in New Jersey.

I really wish I had purchased a direct vent model.

[Gary Swart]

Before it's over, you're going to wish you had not gone tankless.

[Noth Jersey]

Yeah, it seemed like a practical solution to fill a 200 gallon garden tub and to get the tank out of my home theater.

[gregsauls]

Yeah, it seemed like a practical solution to fill a 200 gallon garden tub and to get the tank out of my home theater.

Don't let the anti-tankless gang talk you down. You have the right idea, just the wrong implementation. Put that indoor unit in an area that shouldn't freeze and all will be well. I bet there is somewhere in that basement this unit can go????