# Solar sidewinder DHW HX coil



## mustash29 (Feb 2, 2014)

Just surfing around and came across this interesting design.  While it is set up for a 1" electric element port, the design looks super easy to build and could easily be upsized to larger port openings, like on boiler storage tanks, etc.  I especially like the use of coiling the wire around the tubing to make turbulance and increased surface area.

http://www.amazon.com/The-Solar-Sid...-10&keywords=solar+water+panel#productDetails


----------



## bmblank (Feb 2, 2014)

A nice simple way to incorporate heating dhw with a wood boiler. Essentially make your electric water heater into an indirect water heater.


----------



## mustash29 (Feb 2, 2014)

Yep, reminds me of a modified "hot rod HX".

Being designed for a 1" port, the 1/2" supply and return is rated at only 2.5 gpm.  I'm sure one could upsize that and use a 1.25" or 1.5" anode rod port as well.


----------



## Bad Wolf (Feb 5, 2014)

Hmmm. I think I'm finally going to hook up my 6 solar panels this spring.  My concern was I have a 1200 gallon storage tank and thats a lot of water to heat up.  I have an electric tank that I plumbed in such a way that I can get my DHW either through the storage tank only, through the electric tank only or through the stoarge first then thru the electric.
I was thinking I could pass my solar hot water through this sidearm in the electric tank first then the storage tank. I've got 126 sq ft of panels and I think that would heat the electric tank (40 gallons?) pretty quickly and any extra could dump into the storage.

Thoughts?


----------



## GaryGary (Feb 5, 2014)

Bad Wolf said:


> Hmmm. I think I'm finally going to hook up my 6 solar panels this spring.  My concern was I have a 1200 gallon storage tank and thats a lot of water to heat up.  I have an electric tank that I plumbed in such a way that I can get my DHW either through the storage tank only, through the electric tank only or through the stoarge first then thru the electric.
> I was thinking I could pass my solar hot water through this sidearm in the electric tank first then the storage tank. I've got 126 sq ft of panels and I think that would heat the electric tank (40 gallons?) pretty quickly and any extra could dump into the storage.
> 
> Thoughts?



Hi,
What kind of tank is the 1200 gallon tank?  I'd guess its not pressurized?  How do you transfer heat from the solar heat storage tank to the potable water for water heating?
Is the tank well insulated?

1200 gallons is a lot of storage for 126 sf of collector.  The usual rule of thumb is 1.5 to  2 gallons of water per sqft of collector -- so, maybe 250 gallons.  
It sounds like you have quite a bit of collector area for one family for domestic hot water, and I think this makes more storage than the 2 gal per sf desirable in that you can have stored hot water for a day or two of cloudy weather.

The capacity of that SideWinder is pretty small compared to the collector size you have -- they recommend 13 sf of collector for one SideWinder.  I think that given what you have, there might be better ways to spend the SideWinder money?

Gary


----------



## Bad Wolf (Feb 5, 2014)

Gary, Yes its non pressurized. Actually its the storage tank for the wood furnace. I have 2 150 coils in parallel from the furnace, one 150' coil in the tank for DHW and one 150 coil that will be from the solar panels.  Its wrapped in over 10" of insulation, sits on 4" of pink foam board and is covered with 2" of foam board with 6" of insulation on top of that. There is very little standby loss.
Its going to supplement the furnace in the summer. The panels were free and I'm just trying to figure out a way to utilize them, so its more in the way of a science project. I calculated that the panels could supply about twice my daily hot water needs.  
I saw where they said it would only support 13 sf of collector. So I assume it would only be able to shed a certain amount of heat before it continues to the main storage tank where it would dump the rest of the heat before going back out to the collectors.
The way I have it plumbed I can use the main tank as a preheater for electric tank.
I'll try it the standard way and see what happens.


----------



## mustash29 (Feb 5, 2014)

I posted the link because I had never see this particular design before, thought it was a cool idea, being able to install it in a lower electric element port or maybe in an annode port.  Looking at the specs, the flow rate seems awfully low, maybe a standard side arm would yield more flow & just as many BTU's?

Bad Wolf - I think I would run the solar to a DHW side arm, then to the tank coil.  Like you said, if the sun is out, heat the DHW first, then charge storage, which can pre-heat incoming water.


----------

