Econoburn 200 heating the pool

[goosegunner]

I started using my Econoburn 200 to heat my pool last week. After observing for a while and adjusting the pool bypass it is working very well.

It went from 58 degrees to 82 in two days of 12 hour burns with a uncovered pool.

First thing is My temp gauges( push fit into well ) suck and aren't real accurate.
Boiler set point 190
Return line pre danfoss 140
Bypass valve to danfoss opened to increase return to boiler to 160 degrees

I am getting about a 30-35 degree delta t after adjusting pool water bypass. (Temp gauges at exchanger)


Using the set point of 190 when the fan is off it will cool down to 180 and high speed will kick on and crank away brining it back up to 185. This way the boiler fan basically runs steady and maintains a temp of 178- 185.

I have learned with my pool if I want to bring up temp a full load will raise pool 3-4 degrees if covered.

Best thing is Virtually no smoke! It will smoke just a little when the fan shuts off at 185 but when pulling that many btus the fan comes back on within in 5-10 minutes.

gg

 

[bpirger]

That sounds great! How much water is in your pool? I know I set up my Garn piping ready for another load (pool) should I ever get the chance to put one in. My mother in law spends a good penny heating her 13,000 gallon pool with propane. 24 degrees in two days....that great! 82 is most certainly a good temp to enjoy. And just two 12 hour burns.... 13,000 gallons 24 degrees is about 2.6Million BTUs....so that sounds about right at just over 100,000 BTU/HR.

Do you keep it in the low 80's or do you jack it up higher?

 

[flyingcow]

I have an 18x36 inground pool.I am also curious how many gallons is your pool. Right now i have propane heater. Once summer kicks in, the pool stays pretty close to 72/74 on its own. With a good cover it pushes 76. And when we got plans for the pool we crank up the propane. The unit I have will bring the pool up 2 degrees an hour on a cloudy day. But we only go thru about 100 gals of propane a yr. If i maintain above 80 for any length of time, the chemicals can get pricey. I have some plans on hooking it up to wood, but don't want to heat it constantly. Be curious how you make out. My boiler is only rated for 106,000btu's. Propane, I think is 200,000btu's.

 

[goosegunner]

That sounds great! How much water is in your pool? I know I set up my Garn piping ready for another load (pool) should I ever get the chance to put one in. My mother in law spends a good penny heating her 13,000 gallon pool with propane. 24 degrees in two days....that great! 82 is most certainly a good temp to enjoy. And just two 12 hour burns.... 13,000 gallons 24 degrees is about 2.6Million BTUs....so that sounds about right at just over 100,000 BTU/HR.

Do you keep it in the low 80's or do you jack it up higher?

My pool is a little over 15,000 gallons. I am happy with the results so far. We will only use it to get the pool back to comfortable temp early in the season and after rainy cool days. Many times in Wisconsin it seemed like the weather would get nice after a cool spell but without a heater the pool would be cold on a nice day when we wanted to enjoy it.


This is the break down for pool temps we like.

78-80 you can swim but you better be swimming
84-86 you can stand in the water and be comfortable or float in a tube with a drink and enjoy

We try to keep it at 84-86.

I have 2000' of black poly pipe on 2 manifolds that help us do that throughout the summer on sunny days. I put my pool in myself so when I built it I added returned pipe just for solar heat. It works well that way because I just open a valve and some of the water goes through the loops and returns on its own to the opposite side of the pool. That way you don't have to deal with trying to return a low pressure solar loop into higher pressure pool returns.

gg

 

[goosegunner]

I have an 18x36 inground pool.I am also curious how many gallons is your pool. Right now i have propane heater. Once summer kicks in, the pool stays pretty close to 72/74 on its own. With a good cover it pushes 76. And when we got plans for the pool we crank up the propane. The unit I have will bring the pool up 2 degrees an hour on a cloudy day. But we only go thru about 100 gals of propane a yr. If i maintain above 80 for any length of time, the chemicals can get pricey. I have some plans on hooking it up to wood, but don't want to heat it constantly. Be curious how you make out. My boiler is only rated for 106,000btu's. Propane, I think is 200,000btu's.

I think you would be fine with storage. Without, it would be hard to maintain boiler temp. That was one of the reasons I went with a 200K boiler. If you don't balance pool flow with boiler flow a pool can suck the boiler right down to nothing. My heat exchanger is oversized and if I tried to run all the pool water through it my 200k Can't keep up.

Once I get the tank set up I should be able to increase my Delta t from the pool. I will have to independent things going on with the 1000 gallon tank.

1. Boiler feeding one end of the tank

2. Pool drawing from and returning to the other end

I am hoping that will increase my return temps some even though it will be mixing the tank some. I don't think it will matter too much if the boiler is running wide open and feeding btu's to the tank.

Pool chemicals are cheap if you buy them anywhere but the pool store.

Liquid 12% bleach from Farm and fleet
20 mule team borax for Ph up
Muratic acid for ph down

gg

 

[jebatty]

Sure can do a good job to make a pool comfortable. Congratulations! What makes me wonder, though ...

Using the set point of 190 when the fan is off it will cool down to 180 and high speed will kick on and crank away brining it back up to 185. This way the boiler fan basically runs steady and maintains a temp of 178- 185.

***

Best thing is Virtually no smoke! It will smoke just a little when the fan shuts off at 185 but when pulling that many btus the fan comes back on within in 5-10 minutes.

Essentially you have a 15,000 gal storage tank and still the Econo 200 is cycling? Seems to me that it should burn continuously without ever cycling until the pool is brought up to your desired temperature. My Tarm will not cycle while charging my 1000 gal storage tank until return water [pre-boiler return protection Termovar] gets above 160F. You say your return water pre-Danfoss is 140F. That must mean that your heat exchanger and/or flow rates are not sized/plumbed correctly because the return water pre-Danfoss should be the same as your pool temperature water. The Econo is not transferring to the pool its available btu output. Can you ID the cause of this? And if so, when corrected, your Econo pool heating performance should improve substantially, and you will have far less smoke than you now experience.

Example: boiler supply temperature is 185F, pool water is 85F, delta-T is 100F. Assume Econo 200 maximum btu output of 200,000. Gpm flow of only 4 gpm will move the full Econo output. Assuming no btu loss from the pool, it takes 125,000 btu's to raise 15,000 gal of water 1F, so at full Econo output, your pool temperature theoretically will rise 1.6F/hour.

 

[woodsmaster]

Must have to small heat exchanger or moving to many gallon per min if your ideling.

 

[goosegunner]

Ok, I don't think you guys are understanding me when I say idle. It barely idles, maybe like 5-10 minutes. Smoke is a wisp from the stack some times less depending on the what is left of the load.

Heat exchanger is too big if anything. It is a 360K btu. At this point I would rather idle briefly than have the boiler not be able to keep up. Like I said I could send enough pool water through the exchanger actually drop the boiler to it's knees if I wanted to.

Gg

 

[jebatty]

There should be no idling at all, and in fact, if post-Danfoss return is 160F, "ideal" Econo supply/output would be 180F, nothing higher. I believe boiler output is measured at delta-T of 20F and sufficient gpm's, which in the Econo case would be 20 gpm (20 x 500 x 20). Are you moving 20 gpm's on the Econo side of the hx? or what? What about the pool side of the hx? what gpm's?

Your stated hx rating of 360K is interesting, as it is based on Side A gpm of X and Side B gpm of Y, pressure drop side A of xx psi and pressure drop side B of yy psi, and with that a btu rating is calculated. All that is very important. The pressure drop is converted to pump head, which when added to line pump head and any other pump head in the system then is matched to a circulator that will move the required gpm's in the middle of the pump curve at that pump head, if possible, on both side of the hx.

If you can drop the "Econo to its knees," then increase the flow so that there is no idling at all, Econo supply/output is 180F, and return post-Danfoss is 160F. Then you will capture your full Econo output, whatever it would be, and your performance and efficiency will improve to what it should be. Your goal is not highest temp Econo output, but continuous full burn with no idling.

Of course, the Econo will not likely output continuous 200K, but more likely 150K "average" over a burn load, so nothing here is absolute, except that idling of any kind makes no sense at all, particularly because of your very low system (pool) return temperature.

Certainly do what you want, but IMO absolute no idling is a goal of merit because it represents the highest efficiency in all the circumstances I can think of as they may relate to heating low temperature pool water.

I'm not being critical of what you are doing, just trying to characterize what you might expect with the best possible performance. Maybe you have some over-riding factor that I'm not aware of, and if so, what might that be?

 

[bigburner]

I don't remember all the math, 12,000 gal pool indoors - 175K HX full bore pool side - 6 GPM boiler side. With solar cover on it will raise a degree an hour & the 100k gas heater will do about the same.

 

[Fsappo]

If I can ever afford to get my in ground pool fixed, a wood boiler or solar is gonna heat the water. I like the pool 85 to 90ish. I kept it that temp for a month straight once, because I have natural gas, so I figured it would be cheap (first time owning an in ground pool).

Yeah, $650 natural gas bill that month.

 

[goosegunner]

If I can ever afford to get my in ground pool fixed, a wood boiler or solar is gonna heat the water. I like the pool 85 to 90ish. I kept it that temp for a month straight once, because I have natural gas, so I figured it would be cheap (first time owning an in ground pool).

Yeah, $650 natural gas bill that month.

Ouch!! that would be a very unpleasant surprise.

When I first put in the pool I was searching for a different LP supplier. I told the guy that I chose that I would be burning more the next year because I was probably going to get a heater for my pool. He said " You might want to rethink that, We have had people burn a whole 500 gallon tank in less than 3 weeks." He went on to say that a lot of his customers would buy LP pool heaters and hardly ever use them after the first tank experience.

I really appreciate the honest advice he gave me about the cost. Now that I have learned more about BTU's and heating I know a little more about who it cost so much to heat a pool.

I can heat my house for almost 3 hours at 15 degrees below zero with the same energy it takes to raise my pool 1 degree.

gg

 

[pybyr]

Ok, I don't think you guys are understanding me when I say idle. It barely idles, maybe like 5-10 minutes. Smoke is a wisp from the stack some times less depending on the what is left of the load.

Heat exchanger is too big if anything. It is a 360K btu. At this point I would rather idle briefly than have the boiler not be able to keep up. Like I said I could send enough pool water through the exchanger actually drop the boiler to it's knees if I wanted to.

Gg

GG, just out of curiosity, what do you use to modulate the flow of return water to your boiler in order to keep it from dropping too low?

 

[goosegunner]

Ok, I don't think you guys are understanding me when I say idle. It barely idles, maybe like 5-10 minutes. Smoke is a wisp from the stack some times less depending on the what is left of the load.

Heat exchanger is too big if anything. It is a 360K btu. At this point I would rather idle briefly than have the boiler not be able to keep up. Like I said I could send enough pool water through the exchanger actually drop the boiler to it's knees if I wanted to.

Gg

GG, just out of curiosity, what do you use to modulate the flow of return water to your boiler in order to keep it from dropping too low?

That is one of the things I don't like. I have a danfoss so I had to adjust the ball valve a little more open. The way it is set up now I need to be around near the end of the load to baby sit the coal bed a little. I believe a termovar loading unit wouild work better.

I know Jebeatty says I can push the boiler a little harder and not idle. I know I could but If you run it right to the edge I think there could be times when the boiler temp drops and it won't be able to recover. A good example would be a bridge in the load, some wood that is not quite dry enough, or the very beginning or end of a load.

I have considered putting in an aquastat in the boiler line that feeds the pool zone. If boiler drops below 175 it would interrupt the 24 volt line to zone controller for pool heat.

We have cool weather right now so tomorrow I will be heating again. I will try to push it a little harder and may time the recovery and idle periods.

gg

 

[goosegunner]

Ok I watched the boiler to day while heating the pool.

With the boiler only, no storage these are the times I have. Not really idling because it runs on low speed fan.

Boiler Set to 190
Initially boiler drops to 185 degrees, low speed kicks on

6 minutes Boiler drops to 180 High speed kicks on
Pool will pull down boiler to 176
15 minutes of high speed fan and boiler is back to 185 and low speed.
Cycle repeats

I can increase the amount of pool water running trough the exchanger. Right now I have about a 30 degree Delta T. With the settings I am using it gives the boiler a little buffer to recover if the wood isn't ideal or if it bridges temporarily. It also lets me load and leave it for 3-4 hours without feeling like I have to check the boiler to see if it is keeping up.

gg

 

[rkusek]

Ok I watched the boiler to day while heating the pool.

With the boiler only, no storage these are the times I have. Not really idling because it runs on low speed fan.

Boiler Set to 190
Initially boiler drops to 185 degrees, low speed kicks on

6 minutes Boiler drops to 180 High speed kicks on
Pool will pull down boiler to 176
15 minutes of high speed fan and boiler is back to 185 and low speed.
Cycle repeats

I can increase the amount of pool water running trough the exchanger. Right now I have about a 30 degree Delta T. With the settings I am using it gives the boiler a little buffer to recover if the wood isn't ideal or if it bridges temporarily. It also lets me load and leave it for 3-4 hours without feeling like I have to check the boiler to see if it is keeping up.

gg

At what point does your boiler circ cycle on and off. I think we are thinking like on at 165 off at 160 would keep you in the 160 to 175 or so range for your boiler temps instead of 175 to 190. Flat out for the EB, all high speed fan, no smoke,highest efficiency possible. Should heat pool faster with less wood. When heating 1000 gal storage from 120 to 180, idling would be tougher to completely prevent, but you are heating pool water from 75 to90 degrees, think that is what others were trying to say.

 

[willworkforwood]

Ok I watched the boiler to day while heating the pool.

With the boiler only, no storage these are the times I have. Not really idling because it runs on low speed fan.

Boiler Set to 190
Initially boiler drops to 185 degrees, low speed kicks on

6 minutes Boiler drops to 180 High speed kicks on
Pool will pull down boiler to 176
15 minutes of high speed fan and boiler is back to 185 and low speed.
Cycle repeats

I can increase the amount of pool water running trough the exchanger. Right now I have about a 30 degree Delta T. With the settings I am using it gives the boiler a little buffer to recover if the wood isn't ideal or if it bridges temporarily. It also lets me load and leave it for 3-4 hours without feeling like I have to check the boiler to see if it is keeping up.

gg

At what point does your boiler circ cycle on and off. I think we are thinking like on at 165 off at 160 would keep you in the 160 to 175 or so range for your boiler temps instead of 175 to 190. Flat out for the EB, all high speed fan, no smoke,highest efficiency possible. Should heat pool faster with less wood. When heating 1000 gal storage from 120 to 180, idling would be tougher to completely prevent, but you are heating pool water from 75 to90 degrees, think that is what others were trying to say.

The high speed on my EB 150 fan is basically useless. It drives way too many CFM, burns too fast, and creates very high stack temps. I used to use it for starting fires with a cold boiler, but no longer even do that - I just allow for longer start-up times and use the more efficient lower speed. Last year I even changed a dip setting on my controller (TC33) to slow the low speed setting down even further, which resulted in better stack temps and less wood consumption. So, high speed would not be an effective technique with my boiler. However, that being said, I recall GG that you have the new controller. So, high speed and low speed may not be the same on yours as it is with the TC33. If you have some doc on your controller, perhaps it may be worthwhile experimenting with fan settings, cutoff, and diff - just be able to get back to the factory settings ;-). But I think, given that your fan is continuously spinning, you're probably doing just fine asis.

 

[goosegunner]

Ok I watched the boiler to day while heating the pool.

With the boiler only, no storage these are the times I have. Not really idling because it runs on low speed fan.

Boiler Set to 190
Initially boiler drops to 185 degrees, low speed kicks on

6 minutes Boiler drops to 180 High speed kicks on
Pool will pull down boiler to 176
15 minutes of high speed fan and boiler is back to 185 and low speed.
Cycle repeats

I can increase the amount of pool water running trough the exchanger. Right now I have about a 30 degree Delta T. With the settings I am using it gives the boiler a little buffer to recover if the wood isn't ideal or if it bridges temporarily. It also lets me load and leave it for 3-4 hours without feeling like I have to check the boiler to see if it is keeping up.

gg

At what point does your boiler circ cycle on and off. I think we are thinking like on at 165 off at 160 would keep you in the 160 to 175 or so range for your boiler temps instead of 175 to 190. Flat out for the EB, all high speed fan, no smoke,highest efficiency possible. Should heat pool faster with less wood. When heating 1000 gal storage from 120 to 180, idling would be tougher to completely prevent, but you are heating pool water from 75 to90 degrees, think that is what others were trying to say.

Boiler set point 190
Fan low speed 185
Fan high speed 180



I talked to Econoburn to change the differential but I need to try it again It is fine with my boiler only, but I don't think it will work very well once I get my tank hooked up. The way it works now, at 5 degrees below the set point it goes into low speed fan. It will gasifiy then but not as nice as high. To take a 1000 gallon tank from 180 to 185 on low speed is not going to work real well. I want it to burn flat out until the load is gone.


My pool is a different animal. The boiler running as is has a cushion. If I pull my return temps down any further by increasing pool flow through the exchanger I risk dropping the water after the danfoss to as low as 140. I have it set now to be about 155 to 165 depending on how low the pool pulls the boiler temp before it starts to recover.

It would be very hard to hit the sweet spot of pool taking heat and boiler maintaining an exact temperature of say 180. Once the tank is running I am hoping that it won't matter as much because of the large buffer to shed heat to the pool but also the ability to accept what the boiler will produce at full out put.

gg

 

[jebatty]

I know the Tarm control system (single speed fan) is different than the Econo, but fwiw, if I adjust the balancing valve on the Termovar to maintain 155F, for example, on the return to the boiler, Tarm supply to the system with low temperature storage tank (less than 130F) will be about 175F, 20F over return, and the Tarm will burn flat out, non-stop. My comment may not help anything, but is an example of how my system likely would operate with a pool.

As a suggestion, I might try setting the return to 150F, maybe even 145F, and see if you can maintain high speed fan/burn, with supply at about 170F +/-. I doubt that you would have any return water problem so long as return is 140F or above. I aim for 145-150F minimum return water.

 

[goosegunner]

I will be using it again in a few days to bring pool up to temp for the weekend. It has been cold here. We had 98 degree air temp last Monday and Tuesday. By Thursday we were in the 60's.

With no heat the pool went from 88 degrees down to 70 degrees with the cold nights we have had. This is exactly why I have my set up. Without some type of heat it could take a week of sun to get it off of 70 degrees and be comfortable. About that time we could have another cold snap or rainy day to knock it back down.

If I was dumping hot water into storage My boiler would also run flat out until the setpoint is met. It is a little different trying to balance pool flow to the exchanger.

gg

 

[jason elmer]

Do you keep a solar cover on your pool? It is important to keep a cover on the pool especially at night. Evaporative cooling during the day and especially at night is a major source of heat loss. Orientating the placement of a pool to maximize sun exposure is the best way to improve water temps (good to think about if someone is planning on putting a pool in). If trees are shading the pool it may be wise to cut them down and feed the wood into the wood boiler. More sun more wood warm pool.

I opened my pool in Michigan June 1 and it was 59. With only a solar cover it made 84 on June 5. With the cool down it dropped to 73 and is climbing again near 80.

I have a biomass 60 soon to be installed in the pool house. So this thread is very enlightening. I still plan on heating mostly with the solar cover but the boiler should help even out the temp swings when we get a string of cloudy cool weather.

 

[goosegunner]

Do you keep a solar cover on your pool? It is important to keep a cover on the pool especially at night. Evaporative cooling during the day and especially at night is a major source of heat loss. Orientating the placement of a pool to maximize sun exposure is the best way to improve water temps (good to think about if someone is planning on putting a pool in). If trees are shading the pool it may be wise to cut them down and feed the wood into the wood boiler. More sun more wood warm pool.

I opened my pool in Michigan June 1 and it was 59. With only a solar cover it made 84 on June 5. With the cool down it dropped to 73 and is climbing again near 80.

I have a biomass 60 soon to be installed in the pool house. So this thread is very enlightening. I still plan on heating mostly with the solar cover but the boiler should help even out the temp swings when we get a string of cloudy cool weather.

My pool gets full sun, I use the cover. When you have temps in the low 50's at night and no sun during the day it doesn't matter.

My Econoburn is for doing exactly what you want. It will not be used on a steady basis. But it sure is nice to get the pool to usable temps after the cold spells.

gg