Anybody use one (or more) of these? We're looking into options for our hot water needs. If we went with tankless, it would have to be electric, as gas is out of sight around here.
I read a couple of FAQ's on them, and the bottom line seems to be that they work IF you use them as a backup to solar, or if your HW demands are fairly minimal. One place specifically said that tankless WOULD NOT meet our requirements. I only specified electric, no solar, and the need to do two hot water related tasks at the same time, such as run a dishwasher and the clothes washer at the same time.
So far, I'm not impressed by the concept, but I'd like to hear from folks that have them, specifically addressing initial cost, operating expenses compared to conventional hot water, and whether or not they are up to the task.
I think they are good for places where it doesn't pay to run a network of hot water lines. I wouldn't use them in a house, but if I put a bathroom in my shop or needed hot water in the barn I would consider using one.
We have a hot water furnace and domestic hot water heater that comes in the same boiler package. There is no hot water tank. It works just fine. It's an oil fired unit.
I've seen them in homes, and have even seen an electric one being used as a primary heat source for in floor heat.
There are many different models with different ratings, some will provide more water than others. Alot depends on the temperature of the incoming water (how many degrees does the heater have to raise the water to make it useful).
I believe you are looking for a "Whole House" model. One that is large enough to handle the whole house. The last time I researched these units was a couple of years ago, and there were several available over the internet (both gas and electric) that were claiming to be rated for whole house use. Our local Home Depot carries a good sized gas unit, but I haven't looked at any electric units there.
Good or bad? Don't know. The people I've talked to all seem to like them okay, but the people with tank types like theirs, too. How much hot water do you plan on using?
Well, between showers for three adults, laundry and a dishwasher, we use a fair bit. I'm a big fan of "Hollywood" showers, the longer and hotter, the better [img]/forums/images/icons/grin.gif[/img]
I'm also looking into a Boilermate deal to add to my oil-fired hotwater heat. I suspect that may be the more economical way to go for the volume I use.
That is what I have in my house in NH. We have oil-fired hot-water heating system, but the domestic (tankless) hot water just didin't hold up to our demands. We added the domestic water heater (40 gal. I think) that operates as one zone off the heating system. Pumps out plenty of very hot water and the increase in oil consuption was minimal. Much more efficient than electric.
If you have hot water heat, you can plumb a conventional water heater into your boiler. During heating season, the house boiler will produce domestic hot water. The rest of the year, the water heater will heat on its own. The boiler mates also appear to work great and I see many people who have them. It is rare anymore to find a hot water boiler that isn't connected either to a boiler mate or a conventional water heater (at least in this neck of the woods).
I looked at doing the same thing. Buying an electric water heater at the big box store and connect it to the output side of the tankless. Problem was my 24 year old house has 100 amp service. The dryer, water heater, and stove would eat that up. It was cheaper to buy the water heater connected as a zone, than to upgrade the service to 200 amps.
My uncle owns a hotel in Southern Utah that has about 12 cabins separate from the main hotel. In all of the cabins he uses the Tankless water heaters. He said that he has never had any client complain of lack of hot water, even those that are self proclaimed "long shower takers."
Granted the cabins do not have a full kitchen. According to my Uncle you can run the sink and shower both full on and you don't notice a decrease in temp of the water.
I believe he paid a little over $1000 each unit, they are "Whole house units." Home Depot, here in OK, offers two units a whole house -- about $1000, and a smaller unit for $500.
I asked my uncle if he'd install one of these in a house and he said that they installed one in the restaraunt part of the hotel and have had plenty of hot water. He didn't keep track of what using these saved him or how long it took to recoup the difference between the tankless heater and the normal hot water heater.
We are planning on putting one in our house to use with
Solar heated water. The key with the electric power instant
hot water heaters is your GPM requirements AND the temp of
the cold water supply. The units will heat N number of GPM
X number of degrees.
I did a web search a couple weeks back looking at shower
heads. None of them indicated the GPM through the head.
We don't use hot water to clean clothes so the only hot
water use is the dishwasher, sinks, and tubs. Figure the
shower would be the highest usage....
We saw 140 degree temps out of a solar water heater at a
demo house at NC State. The temp out of our tub was
around 120 degrees. Hopefully the instant heater won't
be use much.
Some states do have some tax credits for solar applications.
NC does. Maybe that will help your hot water needs.