Thermo-siphon question

Thermo-siphon question

PostBy: emposter On: Sat Mar 15, 2008 6:14 pm

I own a Leisure Line Pioneer (90,000Btuh). After the heating season is over, I would like to install a domestic hot water coil. Would an indirect water heater/tank offer any advantages over a typical water heater tank? I have found a new, reasonably priced ($500.00) 37 gallon indirect tank; however I realize that I coould probably pick up an ordinary 40 gallon water heater at a local building supply store for $200.00.
I've searched the forum for ideas regarding heating domestic water. I've been married along time (29 years) :box: . Whatever I come up with has got to work :flush: . The money for this little project is coming out of her "I thought we were getting a new flat screen tv fund." :help:
mike
emposter
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pioneer

Re: Thermo-siphon question

PostBy: Sting On: Sat Mar 15, 2008 6:31 pm

What are you using to make DHW now ?? This could be fairly cheep and simple to do depending.
Sting
 
Other Heating: BurnHAM=NG-gas

Re: Thermo-siphon question

PostBy: emposter On: Sat Mar 15, 2008 10:10 pm

Sting thanks for the quick response. Currently, I'm using a 40 gallon electric water heater which happens to be 40 feet away from the stoker.
This was what I was thinking of doing:
-Re-locate with out re-wiring my existing water heater with in 4 feet of the stoker.
-Elevate the tank so that the drain valve will be parallel to the coil inlet
-Essentially, follow the meyers manufacturing coil installation instructions
-Route the coil outlet to the top of the tank TPV connection
-Then take the hot water outlet and run it into a tankless propane fired water heater.

This is all subject to change based on your last sentence stating fairly cheap.LOL

mike
emposter
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pioneer


Re: Thermo-siphon question

PostBy: Sting On: Sun Mar 16, 2008 9:18 am

I understand you now have a DHW coil in you boiler and you wish to use it. Good - thats less expensive hot water for the family.

But I have several rubs with your plan, First it will be very slow to recover and the aux heater will need to run allot - = no savings... Two you have no plan to limit how hot the tank of DHW may grow to and sending DHW out to taps above code limit of 125 is just dangerous. Others will say they do it because they know its hot - but what about a guest - what about a brain fart moment. Pink body parts are too precious to waste.

Now this might not be as cheep as I hoped but let me give you an "out of the box" suggestion... Your 40 feet from the electric heater. You must be close to a hot water tap at the other end of the house??? Place a tee near that tap and run to the inlet of the boiler DHW coil. Run from the boiler DHW coil out to the bottom (drain) of the electric hot water heater - leave everything in place. Now near the 40 gal electric heater - get a bronze circ pump form the big box store and pipe it to pump into the bottom port, Control that pump with a strap on aquastat on the OUTLET of the hot water heater.

Here is what you get. The boiler makes hot water that you store in your current tank and the aquastat limits the storage to 125-130 max out temp while production is in process. You will have a little loss while pumping your hot water loop - but you have to heat the house anyway right?? When you lift the tap at most of your sinks - since hot water is circulating - you have almost instant hot water. 40 gal of storage is usually enough and when the boiler is in operation above 140 recovery is good - when the boiler is operating above 160 recovery is great! Hi long demand can draw the 40 gallons out quickly because you are also circulating the tank and killing the stratification of the electric vessel but over all the other benefits may be nice to have.

here is how you wire your aqustat to open the circuit on temperature rise:
Image
Image

and here is how I did the pump
Image

If your not near a tap - loop from the BOTTOM of the current domestic electric hot water heater to the (IN) port on the DHW loop leg of the boiler and out back near the HOT port out of the 40 gal heater. This will replace hot water faster but I recommend you or have a plumber install a mechanical thermal limiting valve on the hot water out of the electric heater to the house - because this method will send water heated directly from the boiler to the tap and that could be TOO HOT.. protect your self.
Sting
 
Other Heating: BurnHAM=NG-gas

Re: Thermo-siphon question

PostBy: LsFarm On: Sun Mar 16, 2008 9:35 am

Sting... a LL pioneer is a stoker stove... the domestic hot water coils made for these suplemental heating unit only absorb about 1000-2000 BTU per hour from the stove at 1 gallon per minute water flow.

So what emposter describes is a very normal functional system with a standard DHW coil in a stoker stove.

The way they work, and why they work is that most domestic hot water is used in the morning for showers, or evening for showers, laundry, dishes etc.. So while the stove is making heat all night long, or all day long, usually 8 hours or so, the coil is absorbing and storing heat in the exsisting hot water heater tank.. it gets pretty hot sometimes,, depends on the setup.
Then when the water is used, the tank is refilled with cold system water, and if the water use is too great, yes the DHW heater will have to kick in for recovery, but the system had a full tank of hot water to use for 'free' and there was no use of electricity,gas or oil to keep the tank warm all day or night.. So the savings is usually about 60-80% over no coal heating coil in the system.

Now boilers are another animal.. they can heat a small house or an apartment with their hot water coil.. I heat my shop floor with my hot water coil in my boiler.

Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Thermo-siphon question

PostBy: Sting On: Sun Mar 16, 2008 9:49 am

oppps again.....

Thought he had a 90k boiler...

Well hope someone enjoys my hijack of bandwidth to describe my DHW production!

Sorry it didn't apply to your thread eompostor.
Sting
 
Other Heating: BurnHAM=NG-gas

Re: Thermo-siphon question

PostBy: LsFarm On: Sun Mar 16, 2008 9:51 am

Not the first time,,, won't be the last... good post though! :lol: :lol:

Greg L.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Thermo-siphon question

PostBy: emposter On: Sun Mar 16, 2008 3:33 pm

Sting and Greg L,

Thank You!

mike
emposter
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pioneer

Re: Thermo-siphon question

PostBy: Wood'nCoal On: Sun Mar 16, 2008 9:47 pm

LsFarm wrote:Then when the water is used, the tank is refilled with cold system water, and if the water use is too great, yes the DHW heater will have to kick in for recovery, but the system had a full tank of hot water to use for 'free' and there was no use of electricity,gas or oil to keep the tank warm all day or night.. So the savings is usually about 60-80% over no coal heating coil in the system.
Greg L


The DHW loop in the LL probably provides a faster recovery rate then the element in the electric water heater does. Been there.....
Ran out of hot water all the time with the electric. 6 years with the oil heater, never run out. I'm still planning on connecting the loop in the Alaska to supplement it.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Thermo-siphon question

PostBy: emposter On: Mon Mar 17, 2008 6:33 pm

I just priced the 'coil' and the cost sent shivers through my wallet. I have some skills. Would SCH40 304 stainless 3/4 threaded pipe work with 45 els to create the loop?

mike
emposter
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pioneer

Re: Thermo-siphon question

PostBy: WNY On: Mon Mar 17, 2008 6:50 pm

I wouldn't put any connections INSIDE the stove. It should be a complete loop, if you had a leak, you could create steam or drown your stove or both and have a real mess.

The HilKoil coils are less then $200, plus whatever piping, pumps, etc.. you may need.
http://www.hilkoil.com/product.htm#table
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon

Re: Thermo-siphon question

PostBy: LsFarm On: Mon Mar 17, 2008 6:54 pm

If you have access to 3/4" SS304 tube, can you get it mandrel bent into a loop?.. Then you would have the same as is commercially available.

GL
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Thermo-siphon question

PostBy: emposter On: Tue Mar 18, 2008 9:38 pm

Greg & other distinguished members

I've aquired 7 feet of 316 SCH 80. I'm and industrial electrician by trade. Even with a Greenlee hydraulic bender, trying to put essentially a 180 degree bend flattens out the curve. I am going to set up a jig on a welding table and heat the pipe and bend it that way.

Two questions:
1. Any Idea how long the coil should be? For example, the length of the U-tube from the back pf the bend to the end of the threads.
2. After bending the coil, what would be the ideal center between the laterals of the U tube?

Thank you in advance

mike
emposter
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pioneer

Re: Thermo-siphon question

PostBy: Yanche On: Tue Mar 18, 2008 11:10 pm

emposter wrote:Greg & other distinguished members

I've aquired 7 feet of 316 SCH 80. I'm and industrial electrician by trade. Even with a Greenlee hydraulic bender, trying to put essentially a 180 degree bend flattens out the curve. I am going to set up a jig on a welding table and heat the pipe and bend it that way.
mike
Before you attempt to bend the pipe fill it with sand and cap the ends so it can't come out. The sand will resist the crushing of the pipe. If you want to be sure it doesn't crush, pour molten lead in first. Then melt and remove after it's bent. There's a commercial product, Cerro-Bend made for this purpose.
Yanche
 
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

Re: Thermo-siphon question

PostBy: Scottscoaled On: Wed Mar 19, 2008 12:53 am

There are 80 gallon stainless steel boilermates listed in craigslist in the providence R.I. section. The people will take $150 a piece. These units sell new for $2300 or so. They have 8 left. They used to have 12 :) A circulator pump and a tempering valve would give you all the water you could use. :) Scott
Scottscoaled
 
Stoker Coal Boiler: EFM 520x3, 700 Van Wert 800
Hot Air Coal Stoker Furnace: EFM 150, Keystoker 150
Coal Size/Type: Lots of buck