Solar water heater install - logistics questions


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Old 02-18-12, 09:56 PM
J
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Solar water heater install - logistics questions

As the title says, I'm considering installing a solar water heater in the near future. I plan on doing most of the "grunt work" of the installation myself, but will hire a plumber for the more complicated parts. I'm trying to plan out the whole thing before I start buying, so I have a few questions. Sorry for the long post...

The water heater I'm going to replace is over 20 years old, and surprisingly in good shape. It's a gas heater, in the attic. There are no signs of leaking, but we are starting to run out of hot water quicker than before, so I figure it's time to replace it. Louisiana adds a 50% credit to the federal 30% solar credit, so solar water heating will actually end up being relatively inexpensive.

I don't want to put the new tank up in the attic. It's 105 gallons, and I don't like the idea of that much water (and weight) being in the attic. I have a big enough closet next to my washer and dryer to put it there, but I would lose a lot of storage space. Can you put an electric water heater outside in a water heater shed? I've seen a few people have their heaters outside, but they were all gas. The solar water heater I want to get has a backup electric heating element in the tank for when there isn't enough sunlight to provide all the heat. I have a relative who is an electrician, so I can probably get him to run the 220V for a case of beer.

My next question is really basic, and shows my lack of plumbing knowledge. Can you hook up the water heater anywhere in the water lines? What I mean is do I need to connect the existing hot and cold lines from the current heater to the new one, or can I tie into the closest hot and cold lines to the water heater and just cap off where the old heater tied in? Either place I put the new heater is going to be at least 25' from where it currently is, so I'd prefer to do the shortest amount of new plumbing. I've moved water lines and added new ones before, so I can actually do that part myself. I just don't know if it will work the way I want to do it.

Thanks for any help you can give me.


Josh
 
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Old 02-19-12, 05:38 PM
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Move the heater anywhere but just make sure you size the pipe correctly. 3/4"? 1"? You dont want to lose flow rate.

Not sure how much the packages are but the heaters run about 41500 without the panals.

Cirrex® Solar Electric System - Water Heaters Residential by A. O. Smith

With 30% tax rebate I am not sure you will save any money in water heater or get payback until possibly 20 years.

You could probably replace 5 or so gas heaters for the price of the solar package.

Do you need 105 gallons?

Also you are going to have trouble with the new style gas heaters if you put it in the attic. I would lean towards a unit that takes the air from outside if you reinstall in the attic.

There are a lot of variables. Just wondering why your thoughts on going solar???

Mike NJ
 
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Old 02-20-12, 03:15 PM
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I probably don't need the 105 gallon. The same system is available in 85 gallons, but I found a store that has the bigger one on sale for $100 more than the 85 gallon version. It's $5300, so after state and federal credits, I'm looking at $1060. Installation costs are covered by the credits also, from what I've read. I'm estimating that my fuel costs for my current water heater runs at $40-50 a month. The only other gas appliances I have are a dryer and my heater. I pretty much never run the heater, and my gas bills run $60-70 a month. I figure the solar will cost about $600 more than a cheap gas water heater, so it won't take too long to pay for itself. I have decided against putting the heater outside - too much extra plumbing involved.

This is the system:

Rheem Solar Water Heaters Series
 
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Old 02-20-12, 04:11 PM
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Just remember what you think you might save on gas may be kind of null on the electric your going use. You need to do the math.

Example:

The pump is 2 amps. Thats like running a 240 watt bulb. In NJ @ .17 cents a KW and if the pump ran 24/7 that would = $30 bucks a month extra in electric.

The element in the water heater is 4500 watts. If it ran 30 hours a month on cloudy days that would equal about $23 bucks with NJ rates.

So lets say $53 bucks extra on the electric bill. Ahh but lower gas bill right?

But the solar units are more $ in maintainance. So factor that in. Glycol liquid, pumps, elements, etc....

Hmmm... May actually cost more to run a solar set up....


Just saying....


Mike NJ
 
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Old 02-20-12, 04:46 PM
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All very good points. I wasn't thinking about the pump using that much electricity. I think our cost per kwh is around $0.09. $0.17 is crazy - your elecric bills must be ridiculous. I'm not too familiar with the costs of operating a solar water heater, but I think the pump is not supposed to run constantly. It's really sunny here, and I've read people easily get 90% solar energy on average per year. But that's just me reading - I don't know anyone personally who has gone solar. They say you can just unplug the heater and go 100% solar, but I think I'd end up not having enough hot water in the winter.

I plan on reading a lot more about solar water heaters. Unless the current heater completely dies, I don't plan on getting a new heater until close to the end of the year. That way I dont have to wait too long to get the tax credits.
 
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Old 02-20-12, 05:27 PM
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Yeah I am not saying its a bad idea. Just do the math and try to figure your savings thats all.

So many customers I know think they will save big bucks but the reality is you save on one resource but consume another.

Just something to think about also like I said if you dont need that big heater you can cut your bill in half probably with a 40 gallon. That 100 gallon you have is probably 80,000 btu. A 40 gal is about 40,000 btu. So theres half the gas use.

Just throwing this info out there for you. Its all up to you.

Mike NJ
 
 

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