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View Full Version : Tankless Water Heater for Sap Pre-heater



jmcglasson
02-24-2014, 09:33 AM
Just wondering if anyone has ever used a small tankless water heater to run their sap through as a way to pre-heat the sap before going into your pan? The idea occurred to me recently but haven't tried it. Does anyone do this or know why it wouldn't work?

bannonbush
02-24-2014, 12:23 PM
cant see why I wouldn't work..neat idea! would want to flush it well after use to make sure its good and clean

steve J
02-24-2014, 12:27 PM
That does sound like a good idea!

DaveB
02-24-2014, 01:15 PM
That's a good one! I've been eying one of these for situations when the power is out to have a hot water supply:

http://www.amazon.com/Eccotemp-L5-Portable-Tankless-Outdoor/dp/B000TXOJQ4/ref=sr_1_2?ie=UTF8&qid=1393268928&sr=8-2&keywords=portable+hot+water+heater

For $120, it's cheaper than other pre-heater options. The only thing I'm wondering is how long a 20lb tank would last. I'd also have to look for a unit that doesn't shut off after 20 minutes. You'd also need something that could handle 30+ GPH.

gcstephen
02-25-2014, 01:43 PM
8886I am new, built an evaporator by using a lawn mower cart and placing a used dining hall warming pan on it. I removed the elements and placed a turkey propane fryer burner under the pan. Then ran a smal diameter copper tube in the cart down low, up and around the burner, and out the side of the cart and up into the pan. Sap comes out at 200 degrees. Have to be careful and not let sap boil in tubing. Flow has to be fast enough, and this may filll your pan faster than boiling off the sap.
Then after sap is gone, add fresh water and recycle (move the tubing out of the pan and to the side). This give plenty of hot water for cleanup. See picture for my first ever evaporator. I am not using the coil system on this run, but using a standard metal pot with a drain valve. This sytem has better control, but does not warm the sap as much.8885

maplestudent
02-25-2014, 02:09 PM
I must say, the Homemade Equipment section of this forum is the epitome of the phrase "where there is a will, there is a way"

spud
02-25-2014, 07:43 PM
Just wondering if anyone has ever used a small tankless water heater to run their sap through as a way to pre-heat the sap before going into your pan? The idea occurred to me recently but haven't tried it. Does anyone do this or know why it wouldn't work?

I bought a new direct vent tankless water heater when I was living in Alaska. They work great and cost very little to run. You would have no problem getting 3-4 gallons per minute out of it. Seems like this could feed a 3x12 rig with no problem. Sounds like a great idea that someone needs to look into.

Spud

not_for_sale
02-25-2014, 07:50 PM
Problem is likely that the heat exchanger is going to be covered with something that isn't going to make this solution work vey long.

spud
02-25-2014, 07:52 PM
I wonder if you flushed it with hot water after every boil?

Spud

lpakiz
02-25-2014, 07:55 PM
8886I am new, built an evaporator by using a lawn mower cart and placing a used dining hall warming pan on it. I removed the elements and placed a turkey propane fryer burner under the pan. Then ran a smal diameter copper tube in the cart down low, up and around the burner, and out the side of the cart and up into the pan. Sap comes out at 200 degrees. Have to be careful and not let sap boil in tubing. Flow has to be fast enough, and this may filll your pan faster than boiling off the sap.
Then after sap is gone, add fresh water and recycle (move the tubing out of the pan and to the side). This give plenty of hot water for cleanup. See picture for my first ever evaporator. I am not using the coil system on this run, but using a standard metal pot with a drain valve. This sytem has better control, but does not warm the sap as much.8885

Well, just when I think I have seen it all, ..........an evaporator on a garden cart!!

325abn
02-25-2014, 08:00 PM
Be interesting to see some comparisons to see what the cost is. I think it won't be cost effective.

DaveB
02-25-2014, 08:37 PM
Be interesting to see some comparisons to see what the cost is. I think it won't be cost effective.

There's a lot of factors to be sure but I think it's something that is worth considering. I really like how some guys come up with some really creative ways to increase capacity!

gcstephen
02-26-2014, 07:37 AM
The real reason I posted on this thread is that the coil system I built is similar to the tankless water heater. I suppose the water heater has better control. My next project is to build a Steam Jenny!! See pic of coils.88998900
Well, just when I think I have seen it all, ..........an evaporator on a garden cart!!