Hot Water Coil

Hot Water Coil

PostBy: alexw On: Sat Dec 02, 2006 12:40 pm

Hi All - I have a Leisure Line Pocono in my cellar and it doesn't quite throw enough heat to the 2nd floor so I am beginning to research the water coil option.

I would like to attatch to a 50 gal tank with a circ pump and run 1 zone of baseboard to the 2nd floor cold rooms - has anyone done this or anything similar?
alexw
 

PostBy: LsFarm On: Sat Dec 02, 2006 7:05 pm

Hi Alex, I posted on the thread 'tell me it was worth it' and asked to get some recent feedback on the hot water coil installations George-NJ and wenchris did.

One major item about hot water baseboard, the water needs to be at least 150* to be effective. So you may have to really keep the stove 'cooking' to get enough hot water from the coil.

I'd lean towards keeping at the warm-air movement that you have been working at. There is a lot of costs involved in creating the hot water heat system and running the copper up to the second floor.

How warm [cool?] is the second floor? How warm do you want to try to keep it??

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

PostBy: stokerstove On: Sun Dec 03, 2006 10:58 am

Alex, I did basicly what you're thinking of with my old Alaska Stokerstove. I already had the coil (double) and used my existing 50 gal. water heater tank for my domestic hot water. I have an unheated family room that is farthest from my stove and wanted a little more heat in there. I put a 4' baseboard unit in the room and plumbed it into the existing loop between my stove and the tank. I isolated the new loop with valves to regulate when I wanted heat in that room - nothing fancy.
I agree with LsFarm about the need for high hot water temps to make it work properly and I was a little disappointed the first year I installed it. This year I took a different approach. Instead of waiting for the room to cool, then turning the valves for heat, I just kept them open and so far the room has stayed at 70 degrees or above. I also realize that we didn't hit the coldest temps yet but I haven't had the stove cranking yet either. Looking back I wonder if a 6' or 8' unit wouldn't have been better. The room is about 250 sq. ft. I am using the coil for ALL my domestic hot water and partially heating a room so I don't think I can ask anymore from this stove.
If you are going to use the coil for heating the whole 2nd floor then I think it would be a stretch w/o a coal boiler sys.
Right now I'm in the process of adding a register to the ceiling of my warmest room (living room directly above stove) into a bedroom to try and coax a little more warm air upstairs.
Bob
stokerstove
 
Hot Air Coal Stoker Stove: Alaska Kodiak Stokerstove 1


PostBy: LsFarm On: Sun Dec 03, 2006 12:01 pm

Bob, [stokerstove] thanks for the feedback.

There is a formula for the BTU/hr output for each foot of baseboard. It is based on the water temperature. I don't have access to the formula anymore, my father had it in his head, and unfortunately, my father is gone now. He was a heating engineer among other abilities.

Your method of just running the water, even if it isn't at a really effective temperature is what I had to do with my first undersized boiler. You can get heat into a room with water at only 100-120*, but it needs to be running continously.

The low temperature differential between the heated fins and the air isn't enough to create much circulation through the baseboard either.

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

PostBy: stokerstove On: Sun Dec 03, 2006 5:08 pm

Greg, I keep my water circ. all the time for the domestic hot water anyway. Couldn't justify the added costs vs. benefits of adding an aquastat. I have all my plumbing insulated but I'm sure I lose some heat as the water travels thru the sys. but on the flip side when the aquastat shuts down the pump, all the water in the pipes,besides the coil, cools down anyway. That little Grundfos pump doesn't pull much elec., I'm just not sure how long they last and what is going to happen when it dies. I would imagine the pressure relief at the stove will begin to blow.
Bob
stokerstove
 
Hot Air Coal Stoker Stove: Alaska Kodiak Stokerstove 1

PostBy: George-NJ On: Sun Dec 03, 2006 10:19 pm

I have my coil going directly into the return line of my baseboard that runs behind the stove. I have that one zone all the time. With the over night temp of 24, my coil was puming out 115-120.
You wouldn't know it was cold outside till you looked out the window and saw all the frost.

I couldn't do that last year with no coil and a three fans running trying to push the air around. It is apples & oranges the difference the coil makes.

The hot water runs thru the oil boiler (which is off) then tru the one zone that heats the far off rooms of the 2 story 4 bedrooms addition.

It's not hot enough to heat the domestic tankless coil in the boiler, so we turn on the oil burner for morning showers.

My design flaw was that I ran the coil not directly over the burn bed, I was afraid of too much hot water. I think there is room to tweak that though.

Just wanted to let you know that I'm havin no problem heating my far off (well insulated newer rooms) with a constant flow of 115-120 degree water. Its about 1500 square feet that would've been very cold even with fans (like last winter).
George-NJ
 

PostBy: George-NJ On: Sun Dec 03, 2006 10:30 pm

I designed & built my adition. The baseboards run the length of the one exterior long wall in each room. I didnt bother with formulas, I wanted as much heat as possible, I figured that I could close/damper the baseboard if the room was too warm.

So if your baseboards are on the small size for your room, your mileage may vary...
George-NJ
 

PostBy: alexw On: Mon Dec 04, 2006 12:35 am

I only have 3 rooms on 2nd floor and would probably install a 4 or 8 foot baseboard in 2 of the rooms. I assumed I would just let the circ pumps run all the time. I would use pex instead of copper fof ease and installation cost.

I was wondering about coil efficiency and thought about using a coil from a coal boiler. They seem to be a bit more capable, but I really haven't researched it enough. Seems to me you could get in "hot water" if you don't know what your doing.

I did also buy some 8" duct, a 8" booster fan and will monkey around with 2 of my 1st floor registers this week

As for cutting holes from 1st flr to 2nd flr bedroom - that is where I draw the line. No privacy, all sorts of light and sound transmission. My wife goes to bed early and sleeps light - it would never work.
alexw
 

PostBy: George-NJ On: Mon Dec 04, 2006 9:26 am

Alex,

I ran a duct with a fan booster & doorway fans, too. They helped but didn't cut it in my situation.

Pex would be great, I would also put in more baseboard than you think you need, you could always shutter the damper on them if you want.
George-NJ
 

PostBy: LsFarm On: Mon Dec 04, 2006 9:44 am

Alex the coil from a boiler... do you mean one that is for making domestic hot water?? These are immersion coils made usually of copper. At least the one in my original small boiler is copper. And it is shaped wrong, it is about 4" in diameter and about 36" long. Made to be threaded into the water jacket, immersed in the boiler heated water.

Copper won't last in the heat in a coal firebox, you need a stainless steel coil. You may need to bend your own to get several passes through the firebox for the amount of heat you will need. Like George-Nj did.

George-Nj may be able to help....

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

PostBy: Sterling On: Mon Dec 04, 2006 7:54 pm

I have a water 'front' in our Glenwood Home Grand, and have had so for over ten years, I guess. I have it tied into the livingroom zone of our baseboard.

I offer the following:

I expected that it would thermosyphon sufficiently to keep the coil OK. It didn't. Not being a complete optimist, I incorporated a circulating pump in the loop. Anyway, the long and short of not keeping the coil sufficiently cool (Made of red brass, by the way) was that I had to replace several bits of pipe that make up the loop.

I find that, even if the temp is on the low side, having the water constantly circulating through the base board keeps the room comfortable on all but the coldest days.

Now, if anyone has suggestions for some sort of low-limit switch I could strap on to the plumbing to control the circulation pump, I'd love that. Everyone and their brother has high limit (kills power at hi temp, I want to do the opposite)

Hope this helps.
Sterling
 

PostBy: Yanche On: Mon Dec 04, 2006 9:18 pm

HONEYWELL L6006A1244 Circulator Control, High Limit or Low Limit Aquastat Controller with 100 F to 240 F operating temperature and 5 F fixed Differential.

It has a SPDT switch so it can be wired to turn a pump on or off. There are others that have adjustable differentials. Make friends with a plumber that installs boilers. The old leaking boilers that they junk usually have working aquastat contols. Likely you get the control for free by just taking it off.

Yanche
Yanche
 
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

PostBy: Sterling On: Tue Dec 12, 2006 10:15 pm

Thank you, Yanche, I'll take a look to see what I can find.
Sterling
 

PostBy: BurninCoalInRI On: Wed Dec 13, 2006 10:02 pm

Question: Why not just run the circulator pump when the combustion blower is on? In my case, since I only have 1min over-run on the blower, I may just plug it into that.

I highly doubt the stove makes much useful heat when its not in run mode... i can touch my stove easily when the coal bed is in 'sleep mode'... and it makes LOTS of heat when its on. just run the pump then.... no?
BurninCoalInRI
 

PostBy: Sterling On: Wed Dec 13, 2006 10:12 pm

BCI, that may well work for you with a proper furnace, but I'm working with a cookstove, no blower (no electricity (well not much, anyway) back then) ;).
Sterling