"Can I get a Rinnai Tankless Water Heater in my attic?"

Climate zone 5 is Indianapolis, Indiana.I live in a very small house, 1000 sq ft., so I want to free up the large closet that currently holds the furnace and tanked water heater, both natural gas.I am replacing the ducted hvac system with a mini-split and converting the tank water heater to tankless.I want to put the new water heater in the attic.Is one location preferred?I don't know if I need to purchase a unit designed for outdoor use.

It's very easy for plumbing pipes to freeze if they are located in an attic or crawl space.If you are talking about an unvented conditioned attic or crawl space, either location is protected from freezing.

I don't know if plumbing pipes are susceptible to freezing in Indianapolis if they are located in a ventless attic or crawl space, but I suspect so.

It costs less to create an unvented conditioned crawl space if both locations are vented.

For a long time, we had a propane tankless in our attic.When I put the unit near the floor of the attic, the piping went straight down through the insulation and into the house, so very little was exposed.Electric freeze protection is built into a lot of them.

Which location will be easier to run gas to and run the vent from is part of your question.The unit had a cat.The attic is made for an easy vertical vent with few pieces.

You could put the laundry in the closet out of the way.I see that done a lot.You don't have to worry about cold pipes if you do that.

After spending half the day trying to figure out what was best, I decided to go with the attic because it was easier to access and it required more maintenance.There will be a freeze concern because the attic is ventilating.Some of the units I've looked at have built-in freeze protection, either by using an electric warmer or lighting a small amount of gas to keep the temperature above freezing.The first thing that comes to mind is (1)

I'm not sure if an outdoor model would work in an attic.Is it possible to install outdoor models in cold climates?Since they are installed outdoors, they must have freeze protection.I don't know what hot tub on a deck is used for.

Since I can't afford spray foam, I'm going to insulate the block walls and rim joist with rigid polyiso, which I bought for next to nothing.I'm putting plastic on the floor.The small access door that opens into the yard from the crawl space is something I'm thinking of eliminating.That would make my house unvented.I'm wondering if putting in a mini-split will make my house no longer conditioned.No leaking ducts down there to condition it.It seems that the freezing risk is still lower in the crawlspace.Less damage would occur if the leak was in the crawl space.

If I had to put the utility closet in the living space, it would cause a problem with ventilating because it is not connected to an exterior wall.I would like to use a direct vent model.

Since I last looked into tankles water heaters a year or so ago, prices have come down a lot.I don't know why.Is the fad over?The Chinese government may be subsidizing them.Is it possible that Martin's article "Are Tankless Water Heaters a Waste of Money?" could force suppliers to suppressed them?

There is a catalog at www.aquahstore.com.

David, outdoor-rated tankless water heaters are installed on an exterior wall in a warm climate.You don't have to worry about the cold water supply pipe freezing.

You don't have to worry about the water heater unit freezing if you install it in an attic.The cold water supply pipe is very likely to freeze.If I were you, I wouldn't install the water heater there.

Even without ducts, a conditioned crawlspace would be the better location for the tankless than the attic because of the huge heat loss.If you side-vent the vent, make sure it's protected from snow drift.

Even with cheap natural gas, it's worth the extra hundred to go for a heating & cooling mini-split.It's cheaper to heat with the mini-split during the shoulder seasons because of the high heating efficiency of those beasties.It's pretty good if you have an HSPF >9 and there are some relatively low-cost options.Unlike hot-air furnaces, mini-splits have a stable room temperature.

Before you buy one to install in the crawl space, make sure you read up on the clearances required, especially headroom above the unit.

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