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Hybrid water heaters

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Wifey and I are treading on thin ice with our 16+ y/o water heater and I have been looking at a replacement. I finally dissuaded her from the tankless route, and we are both very interested in the new hybrid units. I know they are a new(ish) technology, but has anyone had experience with one?

I am planning on putting it in the extant location, in the central heat/air driver room. It requires 68 degree ambient temp for heat exchange-only operation, and I believe with the HVAC next to it that should help drive temps up. We used to keep a big freezer in there, but moved it to the garage a few years back. Maybe I could relocate it back in there and scavenge the heat produced by its condenser. My refrigerator is not too far from it; I could route a duct from underneath the kick plate and use it as an auxiliary heat source. I thought about running the dryer vent into the room, but moisture would be a concern, unless Iran the duct right into a dehumidifier. I chose not to get a dehumidifier when I put in the new HVAC last year, perhaps it was a mistake, but the installer did not see a need for it, and the way I look at it, he had nothing to lose by installing one.

I would love to scavenge all heat possible.

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I've often wondered about hybrid systems, or even using the heat generated by an air conditioner to heat a pool (it gets cold in Canada you know...). The only answers I have been able to get is that an electric element water is almost 100% efficient. I'm not counting line losses and transformation to get the power to your house, just once it's inside.

I found some information about the various prices on Water heating and it seems like the heat pump is the least expensive in the long run. I haven't seen any convincing numbers on the first hour ratings, with the hybrid during a high demand, you'd be using the elements and losing your savings.

The thing I like about electric element tanks is it's not high tech and as easy to maintain as an anvil, if it breaks it's cheap to replace and you can get it serviced by anyone any time. I like gas too, and most plumbers can get parts or a replacement unit in hours. I'm not sure how many plumbers know how to fix a heat pump tank, it could require 2 repairman visits and no hot water for a longer time. If the electronic card goes it might take 2-5 days to replace.

The problem with running the dryer into the furnace room is you won't be heating the water all the time. So the humidity could be a problem.

An electric tank is noiseless, but in a basement you wouldn't notice the noise from a heat pump, probably less noisy than a power vented gas fired unit. I like the idea of putting the freezer (and maybe moving the fridge closer to scavenge all the heat.

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We went ahead and got a plain electric one and let the local plumber install it. Simple, and pretty efficient. Only drawback will be when power goes off, we will probably shut it off most of the time to keep generator happy. Of course, during a time like that a hybrid will not be anywhere near peak temps anyway.

We tried to get him to install a timer, but he told us he doesn't do them, they cause too much trouble down the road.

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Hmm...A timer seems like a great idea. I don't see where reliability becomes an issue.

I bet Pat has some at the office...

edit: son of a....this thread is almost a year old?

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Serves him right for not following up with what happened.

So...Phil.....

And what is wrong with tankless? That's the direction we are heading.

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The problem with tankless, in Canada, is the heat loss from your hot water tank will just heat your home, something we have to do for far too long in the great white north. Modern tanks are pretty well insulated too, so there isn't much loss.

Anecdotal but when I went tankless from a high efficiency tank model, my gas consumption went UP. Same house same amount of people etc.

You may also have to change your gas line for a larger diameter, more expense, for little savings. Unless you really need the space is there really a benefit? I did the cost analysis a couple of years ago when the cost of gas was in the high 20 cent/cubic meter and the payback was about 8 years, with natural gas so cheap now you'd probably have to replace the unit before it paid for itself.

One thing I have noticed is some tankless have a standing pilot or an igniter that doesn't need electricity to work so you can still heat water without power, in case you like to bathe in the dark.

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As I said earlier, like last year, I got the regular water heater. Cost was one of the factors. The required yearly maintenance was another. Conditions in the storage closet are not ideal for the hybrid to be efficient.

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Was looking at Tankless... and came across this article. Still haven't decided, but thought I would post this link anyway as a FYI

James

http://www.chandlerdesignbuild.com/files/fhbDecJan08.pdf

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Holy old thread jacking!

With gas the tankless is more efficient for a small household, 3 tops I'm guessing. The difference will be higher if the house spends a lot of time empty, I don't know anyone who shuts the heater off during trips away. Above that a tank is likely more efficient. When I switched I lived alone and saw the drop in the gas use, but I hadn't been draining my tank like you're supposed to and it had over 5 gallons of sediment insulating the heat away from the water. With electric I think a tankless wins no matter what, tho it's probably marginal for a household above 3. If it's electric and inside the house and you always want some extra heat then there's no energy loss using a tank since every bit of heat is being used for the water or the air. The two biggest issues I have with my tankless are: more time waiting for hot water to arrive at a faucet, and the worst part is a lack of controlling a low heat level. I don't take hot showers and in the summer it's impossible to maintain a comfortable temperature. Turn the hot down too much and the heater stops. When the cold water hits and I turn up the hot I have to wait for it again. It has also 'forced' me to waste water; I used to shut the water off between steps while showering but that throws the water temp all to shit with the tankless. My dad had the same temperature issues with his electric tankless so it's not limited to gas or me. One upside is that there's no end to the hot water so 10 people can take showers one after the other with no loss. The downside is that the flow is limited so when two faucets are run simultaneously they impact each other a lot more than with a tank. With a tank if someone turned on hot water while I was showering it would get noticeable cooler and I'd just turn it up, with the tankless it gets very cold and there's no fixing it by opening the valve more if the other consumption is more than a trickle. My showers are the furthest points of use from the heater so that makes it worse. Installing a gas tankless in place of a tank requires a larger gas line and a much larger flue, I had to afro-rig both and installed the smallest unit. A bigger one would have involved re-piping the house for the gas a fair amount of chopping for the flue. With electric they have higher consumption so you have to check that you have the circuit to support it. Tankless are much smaller so that can be an upside. A tank holds emergency water reserves, something rarely thought about. Some more downsides to mine: if the water or flue temp go beyond limits it shuts off and has to be re-lit. Surges in hot water use will sometimes shut it off too, not sure why. It mostly happens when my clothes washer does the spin-rinse cycle in the warm setting, I guess the rapid opening/closing of the water valve does something to the heater. When this one stops working or I get more fed up with it I'll be going back to tank.

The ups & downs are all scattered here but assemble it and see how it looks and do some research. I wouldn't suggest a tankless unless it's a small household and a few dollars in gas are more important than comfort or you really need the space. The savings have to be considered against the higher initial cost, especially if you're paying to have it installed and they have to modify things.

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So there you have it. A self-described wrench guy gives some points that I have never seen in all my research.

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I went through all this research and settled on a 250 electric water heater.

I think there is likely 3x the savings in insulating your house better and going to LEDs for all recessed lighting.

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With a natural gas tank can you put it on a timer, so it only runs at certain times of the day?

I don't see how that could be done. Cheaply, at least.

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I'm looking at removing the large water heater and replacing it with three half-size water heaters -- one for the kitchen/laundry and one for each shower. Right now, the hot water lines have to run all the way across the house through the slab to get to the two showers, and it means you have to run it for quite awhile to get up to temperature. I have enough room to co-locate the half-size water heaters with the showers, and each half-size is worth two reasonable (or one teenage length) showers.

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I'm looking at removing the large water heater and replacing it with three half-size water heaters -- one for the kitchen/laundry and one for each shower. Right now, the hot water lines have to run all the way across the house through the slab to get to the two showers, and it means you have to run it for quite awhile to get up to temperature. I have enough room to co-locate the half-size water heaters with the showers, and each half-size is worth two reasonable (or one teenage length) showers.

Have you considered a circulating pump on a timer to keep hot water at the point of use when commonly needed?

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I'm looking at removing the large water heater and replacing it with three half-size water heaters -- one for the kitchen/laundry and one for each shower. Right now, the hot water lines have to run all the way across the house through the slab to get to the two showers, and it means you have to run it for quite awhile to get up to temperature. I have enough room to co-locate the half-size water heaters with the showers, and each half-size is worth two reasonable (or one teenage length) showers.

Have you considered a circulating pump on a timer to keep hot water at the point of use when commonly needed?

I can't figure out how to do that without taking a jackhammer to the slab and running new lines.

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I'm looking at removing the large water heater and replacing it with three half-size water heaters -- one for the kitchen/laundry and one for each shower. Right now, the hot water lines have to run all the way across the house through the slab to get to the two showers, and it means you have to run it for quite awhile to get up to temperature. I have enough room to co-locate the half-size water heaters with the showers, and each half-size is worth two reasonable (or one teenage length) showers.

Have you considered a circulating pump on a timer to keep hot water at the point of use when commonly needed?

I can't figure out how to do that without taking a jackhammer to the slab and running new lines.

Ah, I see.

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........ in an interview with Perspective Media. “There are products available that comply with the 2015 regulations, but they are generally not yet in the mass market.”........

Yeah, that was written in Oct 2013. After 14 months, I'm interested in how many have made it to the mass market. Looks like a man could buy a few of the old school models and turn them in a few years.

I'm looking at removing the large water heater and replacing it with three half-size water heaters -- one for the kitchen/laundry and one for each shower. Right now, the hot water lines have to run all the way across the house through the slab to get to the two showers, and it means you have to run it for quite awhile to get up to temperature. I have enough room to co-locate the half-size water heaters with the showers, and each half-size is worth two reasonable (or one teenage length) showers.

Have you considered a circulating pump on a timer to keep hot water at the point of use when commonly needed?

I can't figure out how to do that without taking a jackhammer to the slab and running new lines.

Ah, I see.

You could use PEX and run the return through the ceiling?

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........ in an interview with Perspective Media. “There are products available that comply with the 2015 regulations, but they are generally not yet in the mass market.”........

Yeah, that was written in Oct 2013. After 14 months, I'm interested in how many have made it to the mass market. Looks like a man could buy a few of the old school models and turn them in a few years.

I'm looking at removing the large water heater and replacing it with three half-size water heaters -- one for the kitchen/laundry and one for each shower. Right now, the hot water lines have to run all the way across the house through the slab to get to the two showers, and it means you have to run it for quite awhile to get up to temperature. I have enough room to co-locate the half-size water heaters with the showers, and each half-size is worth two reasonable (or one teenage length) showers.

Have you considered a circulating pump on a timer to keep hot water at the point of use when commonly needed?

I can't figure out how to do that without taking a jackhammer to the slab and running new lines.

Ah, I see.

You could use PEX and run the return through the ceiling?

There is no attic space connecting the two halves of the house. It's... irritating.

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From the pumps I saw, you don't need an exclusive return line. Pick your farthest away faucet, install a valve that uses the cold water line as a return, and install pump on hot water heater.

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