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Old 11-12-2012, 05:24 AM   #1
Brichards
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Default Whole House versus Point of Use

Hey Team,
So I am thinking through a strategy for heating the water throughout my house focusing on two things cost efficiency & continuous use.

My home is in Michigan, & I currently have a 50 gallon propane water heater.
During the winter months I have to fill mu propane tank multiple times, and the cost is insane. So I am thinking if I can get to where I am only using propane for the furnace, I should be able to save some $s.

My house is a single level with two baths currently, but I eventually plan on finishing the basement and adding a 3rd. I also have the following places that use hot water.
Kitchen sink & dishwasher
Main floor laundry with washer, steam dryer, & utility sink.
Spicket in the garage that has hot & cold water.

The master bath has a walk in shower with 4 heads running off two lines, dual sinks & an avg size jetted tub.
The guest bath has a single sink,avg size jetted tub with a single shower head, which is at the far end of the house.

The reason I described the setup in such detail is because while looking at electric on demand whole house tankless water heaters, the specifications recommend 200 amp electrical, where I only have 150 amp.

I am wondering if it would work having multiple smaller point of use electric tankless water heaters?
The benefits I see are...
The smaller tankless would each work with the current electrical service.
They could be placed closer to the usage points, eliminating heat loss that comes from long pipe run lengths.
Could have unlimited use for nice long showers & baths.
Could potentially use multiple sources at the same time. Washing a load of whites with hot water while showering, talk about time management!
The efficiencies would save a ton on propane, but the setup could also help minimize the increase in electricity.
If one dies, the house isn't completely out of hot water, and replacement costs would be cheaper.

So I guess my other questions would be...
Am I nuts for thinking this is a good idea?
How many heaters would be recommended, what size, & any brand recommendations?
Any recommendations on placement?
Anything I am not thinking through?

Thank you so very much for any advice, I greatly appreciate it!
And am very excited to get cracking on this project depending on the responses I get here!
Blake



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Old 11-13-2012, 12:25 AM   #2
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I have very limited experience with electric tankless water heaters, but the two or three of those that I have installed that were rated for a bathroom had trouble supplying even a lavatory faucet, let alone a shower.



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Old 11-13-2012, 01:29 AM   #3
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Electric may be more costly to run due to the fact you have gas -- are your applances gas as well?

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Old 11-13-2012, 04:13 PM   #4
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My appliances stove, dryer, etc are all electric. The furnace and water heater are all I have that run off propane. Each winter costs me about $3,000 in propane. Which is the main reason I am looking to make a change.

My last tankless ran off natural gas and saved me $30-$40 a month at my old house.
My electric bill is $60 in winter & about $100 in summer due to whole house A/C.

I know there are electric whole house tankless water heaters that are about 98% efficient, but that would require I upgrade my service from 150amp to 200amp.

Thank you for the feedback. Any additional thoughts would be helpful as I try to save on propane costs and have a longer supply of hot water.

Blake

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Old 11-13-2012, 08:59 PM   #5
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Your winter propane bill is mainly due to the furnace and not so much the water heater. Your water heater will use about a gallon of propane (rough ballpark) a day. So at 30 gallons a month thats only $100 ish or so.

Moving the water heater to electric would not greatly reduce your propane bills. Plus, though electric heaters are more efficient then gas, Overall cost wise its about a wash in cost.

Electric instantaneous water heaters even for a small load like a single sink need 8-9KW just to get half way hot water at the outlet. It would be a lot of money spent for not a lot of overall savings.

If you have a 83% efficient gas furnace, going to a 98% furnace would save you oh about 10% still not a lot.. More insulation in the attic maybe.

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Old 11-15-2012, 01:32 AM   #6
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Beni, thank you for the useful info. Even at only $100 a month, what about a propane on demand?
I could achieve the limitless hot water I am looking for, and maybe save $30 or so a month on the propane bill?
I was surprised to read that a big increase in furnace efficiency would only save about 10%...Seeming more and more that there is no escaping outrageous propane prices. Except maybe a geothermal or wood stove hooked into the duct system (Had one at my previous house, it was amazing).

Also surprised that people aren't heating, water or a home, in more creative ways. Like maybe even having a dual setup, where the gas water heater keeps it luke warm instead of hot, then an electric tankless gets it from warm to hot on demand...

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Old 11-15-2012, 05:18 AM   #7
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I know some companies make a tankless with an orfice conversion for propane instead of natural gas. Believe it was Noritz. But just do a bit of hunting around and you'll find a tankless than can convert to propane easily. I feel that would be your most economical option based on what you want. In the long run the tankless should pay itself off. However with the tankless you will need a softener if you water has any hardness to it at all. And they should be flushed, probably annually or every few years. They do require a fair bit of maintenance but if its what you want it's worth it.

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Old 11-16-2012, 09:00 PM   #8
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I do have a softner already installed. So looks like I will be shopping around for a propane tankless, which I know there are many.
Thank you team!

Anyone with tankless experience have brand/company recommendations for efficiency, reliability, capability & cost?

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Old 11-17-2012, 02:14 AM   #9
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I'm not a fan of navien ( don't know if they can go propane) Rinnai and Noritz I have installed and they seemed to work well and easy install

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Old 11-18-2012, 12:15 AM   #10
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Thank you for the recommendations Steve!
Blake



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