Ultimate DIY Pool Heater | Part 2 - Performance & Results

Part 2 of 2. In this video series I discuss what I have constructed and use to heat my 12,000 gallon pool up to 10°F in a single day.
Part 1 Contents:
- Opening Statements
- Heat Exchanger construction
- Flow Diverter Construction
- Setup Process
- How Not To Use It
Part 2 Contents:
- Heat Exchanger Performance Measurements
- Pool Heating Capability (Based on Real Data)
- Parts List/Cost Breakdown

[@jackonthefarm5540]

I am an engineer and have taught classes on hot water solar design. I also have designed pumping and heat transfer systems as part of my job. I have a couple of comments... 1. The spaces between the tubes inside the barrel are a waste. You allow heat to get to the steel barrel and radiate to the atmosphere. Better to pack the tubing in solid (little to no spacing). 2. Liquid in laminar flow will transfer much less heat at the interface between the SS tube and the water inside than liquid in turbulent flow. Therefore you want turbulent flow in the barrel tubing where you want to maximize heat transfer, and laminar flow in the lines to and from the barrel to minimize losses to atmosphere. This translates to small diameter tubing in the barrel where the heat transfer is taking place, and large diameter hoses carrying the water to and from the barrel. 3/8 or 1/4 inch diameter tubing would not be unreasonable for inside the barrel, and 1" diameter would not be unreasonable for between the barrel and the pool. An efficient hot water solar panel has a 1" header with about 12 - 1/8 inch diameter branches in parallel, leading to a 1" outlet header. My 100 gallon solar storage tank is sometimes at around 200 degrees F. 3. Moving energy is the point of this project. The small diameter tubing inside the barrel will yield a greater temperature rise than the larger tubing. If you calculate the mass of the water flowing times the temperature rise (delta T) you are likely to see larger numbers with the input I suggested here. 4. Doing the calculations the way you are is suboptimal. The pool temp is rising. The heat transfer will be much higher for 60-degree pool water than for 90-degree pool water. 5. Closing the PVC valve and hearing a change in system noise is not due to the pump working harder. With a centrifugal pump, the least horsepower is used at zero flow rate. High total flow rate takes lots of horsepower. What you likely heard was a lower total flow rate but a somewhat higher velocity in the small diameter branch. The velocity makes noise due to turbulent flow. Hope that helps clarify how to think about this stuff.

[@ErikVanRent]

Helps me out a lot! Thanks

[@buttacupss7495]

So would a manifold to the outside help with flow rate. Feels like it should

[@netwrench6570]

BTW, forgot my manners. This is the best video around for pool heating, since it contains verifiable results and careful instruction regarding build. You truly are an engineer based on how you approached this and measured your results with data such as flow and input/output temperatures. I've searched through dozens (or more) videos trying to find a real way to heat my 18,000 gallon above ground, and this is the first time I've had results. I picked up three degrees last night, so thanks! It's going to be 80 today, so maybe I can break 70 (at 65 now). Mine is a three ported manifold system, which I'll expand on as required. I do have an irrigation tube solar panel, and that gets me a couple of degrees as well, so it's a little extra. Keep up the good work.

[@kbdesignz5808]

Well done solo! the data collected is great! I appreciate your effort. Thanks.

[@tonyridge9428]

Thanks for the work you have put into this and for sharing the ideas and results, much appreciated.

[@brentspears82]

Well done!!! extremely informative and complete !!!

[@basidiomycota]

Well done sir! Thank you for such a thorough and detailed video.

[@brianbrink1421]

Great video. Very precise and cover everything.

[@VictorMaldonado-zm3nl]

Great video and amazing way to break down the data for all to understand. Also the material list you provide is phenomenal.

[@squarebelt2089]

Thanks dude! That was a great part 1 and 2

[@joshgall5570]

Very nice. Thanks for the break down and all. Going to test in a 34k gallon pool. And it’s nice to see the added benefit from the sun

[@phatboii0707]

This man here got data and formulas to calculate these numbers !! Nice

[@skydemon02]

Impressive video. Well done sir!

[@kryptokoz7826]

Nice job. Great instructions

[@dezwilliamz]

Might try that out as soon as I get my privacy fence installed. Thanks for the info!

[@LittleHomeProjects]

Great video. I really appreciate the time spent on collecting the data points! So many people start a project like this and don't think it though all the way. One data point I was surprised by was the the faster flowrates had less of an effect. I had always assumed that a faster flowrate would collect more energy from the system. It was very interesting to see the point of diminishing returns for this system. Thanks for the video!

[@JoATTech]

Thx for sharing and the math. You saved me a day of research. I got the barrel already, now I need to buy other pieces. This is YT at it's best!

[@ericjovenitti6747]

This was kick ass great job

[@phildnyc1]

Just the calculations I was looking for - super smart approach to the problem. I’ve seen a lot solar projects but they all don’t factor in the mass / volume of a water body well enough to be largely effective. I didn’t know the way to approach the two volumes (hot and cold) and at what schedule I would need to move temps up so this really helps.

[@DiggerDan87]

Thank you so much this is a brilliant way I'm really looking forward to doing this 😎

[@andreiperim594]

Great job man!

[@logothaironsides2942]

Wow that is very scientific. I love it. We probably wont be able to do it as almost everybody here dries washing outdoors and even a small bonfire makes laundry smell but if you have the space outdoors its a great idea.

[@rogeriolatterza9841]

Congratulations from Brasil!!!!

[@Drxxx]

great idea.. super channel!

[@JR2012now]

Very good video! Best information!! Now can I borrow it for this weekend? lol

[@laynekelly7085]

Awesome video, Man. I, too am a Thermodynamics freak & you hit all the nails on the head. I will be building something similar to this. My plan is to put your design in parallel with a home made solar heater (that I’ll run during sunny days). Our family like our evening back yard fires, so I’ll incorporate a version of your coil into our family fire pit and re-route that lost heat energy back to our pool. Thanks for sharing your calculations as well. I love the efficiency vs cost. Well done, Sir.

[@netwrench6570]

Layne, I think it's not efficient, and SoloEngineer conceded that in the comments below. It is better to put the barrel on it's side, based on my experiments this past fall. I have a 200' irrigation tube solar panel as well, but didn't get enough sun for it to do much. Didn't need it over the summer as it was a hot one. Solar cover is a must have for all. I can provide the details of my setup if it helps. Let us know what you do and how it turns out, very interested.

[@dougowens2686]

Outstanding Thank you

[@BaoTran-bs6jr]

make part 3, I know you didn't stop there. very interesting. I can't wait to start mines. lol

[@richiethesailor629]

I enjoy the math data concept that simply boils down to 2 gallons per minute ballpark optimal flow rate. The stainless 1/2" OD coil is sweeter than copper being stronger & with great conductivity. The clear plastic tube is a good visual point but even better as a blow-out link to minimize catastrophe. I'm now dreaming of incorporating this SS roll size or 55 gal flue size via brick into my "branch burning bbq idea." 🔥 I had tried a copper core from a large heat exchanger hooked to a pump circulating from the pool but it got "unplugged" so it blew!? Inspirational, thanks!

[@reesemartindale5543]

Very epic video

[@reverse_engineered]

Thank you! This video was extremely helpful. It's great to see someone actually run the numbers to determine what it's capable of. With this, we can determine the heat output to be 11.94kW or 40,740 BTU/hr, which isn't too bad. A typical natural gas pool heater is in the range of 100,000-140,000 BTU/hr, but they also cost $1,000-2,000 plus installation. Any idea how quickly you go through wood? It's not free fuel, so we should consider that as well. I wonder if you could get better efficiency out of it. Most of the heat is rising out of the barrel as hot gas. If you look at an indoor natural gas water heater, there is a burner at the bottom and a flue going up through the water. The flue will have a spiral set of fins within it to make a long channel for the hot gasses to go through and a lot of surface area to conduct the heat into the surrounding water. Perhaps a similar thing could be done with the burning barrel by attaching a flue to the top and putting the coil within that flue.

[@celsoruiz4339]

Great idea.... I already built a solar heater but I want to built a fire heater for winter after I built a all season cover.

[@Gavintyler21]

Really liked all the details you put into your video. Great job I’m wondering is there an optimal size to use for the coil? will the heat transfer better with larger diameter and slow water rates or smaller diameter tubing I also wonder if you can incorporate this coil inside of a rocket mass heater around the heat riser? One last idea if the tubing is in in water like a boiler will heat transfer be more efficient?

[@AchillesWrath1]

Interesting video. I've seen this design many times before. I would be curios to see what the flow rate is like without the use of the pump. It might be hard to do that though because the burn barrel and the hoses would need to be lower than the water height for optimal thermosiphoning. In order to do that in this scenario you would need to dig a hole in the ground and place the barrel at a lower height. An easier experiment to produce the same effect would be an elevated 55 gallon water bucket above the burn barrel. It would be interesting to see how the flow rate compares with and without the use of a pump.

[@post-leftluddite]

Awesome... Have you considered doubling the length of the coil and have it do double the run in the fire? Or to out a top on the barrel with a smoke stack to increase the water temp?

[@pachomouse]

This video is really encouraging, my baby girl has a 10 Feet (1240 Gal) pool, temp here is around 62 every day so this system might help. I'm thinking on building ir with a smaller can (26" x 14") with a 1/2" copper coil around 26 to 30 Feet. Il'l let you know the results once done. Most likely it will heat the whole thing within an hour and change.

[@Gozerdje]

Your pool heater can generate more heat when the pipe is run trough the middle of the barrel. Cold air is being pulled into the barel from the sides and the heated air(and flames) will mostly go in the middle of the barrel up.

[@ashow13]

Agreed. Next spring I am going to try laying the barrel sideways and see how that affects the results. I might also try drilling more holes toward the top of the barrel and putting a lid on the barrel.

[@allenwagner7368]

@@ashow13 While burning, the ashes will accumulate on the bottom, thereby covering and insulating that section of coil. If the barrel is sideways, I think more coil may be affected. It might be best to stay vertical and start the coil somewhat up from the bottom to allow for ash accumulation. Great video though. Thanks for all the specifics.

[@louispoche4312]

Looks like it works well... I am using a propane water heater to do the same for my hot tub. But, Convert everything to BTUs...the math is so much easier. Props for figuring it out the hard way though.

[@rebelfrog3]

Thank you for your detailed video. I'm thinking of building something similar but using a salamander style heater to blow heat in the barrel through a hole in the side with a lid on top with maybe a 8 inch hole in the center to create sort of a rocket heater.

[@netwrench6570]

How did it go? I had thought about a rocket heater. Did you see the couple from New Zealand the created an elaborate permanent one with bottles for insulation with clay and bricks. It was for a hot tub, but looked amazing.

[@s.kievit6726]

Hi, thanks for your great work and sharing your experiences! I'm trying to compare different designs and wondering if you thought about having the coil horizontally instead of vertical. My thought; you loose a lot of heat on the top side, which would be optimally used when having the coil laying horizontally and burning the fire inside. Flames more and longer contacting the coil and keeping heat for longer time inside the area where the coil is transferring it's heat to the water. With a chimney on the backside for example. I saw a few designs, but a lot more vertical like yours. You well thought your project, so curious what you think. Thanks!

[@patriotjedimaster1450]

Great videos. I was wondering if you separated your heating system from your pump by using a submersible pump at the bottom of the pool pulling in the coldest water, rather pulling from the skimmer (top of the pool), would the results be better & more efficient? It seems by both pulling & returning water from the top neglects the cold water deep down.

[@jasondodds2875]

Im about to create a hot tub heater this way, horizontal barrel with 200" copper 1/2" tubing on the outside of the barrel and a makeshift refractory on top to insulate. I may do a similar heating graph for funzies when its done. I will certainly update you how its going.

[@rhdtv2002]

That was entertaining..I bought a TCMT tankless 16Liter water heater - cost os cheap. Ran a gas line to it. I have the cold pool water to a water pump then the pressurized cold to the tank and heats it up to around 120degres back into the pool

[@danielroden9424]

you did the math. awesome! would you be better off with a shorter coil inside the barrel with coals touching the outside and inside of the coil?

[@mitchdaniel5605]

Awesome videos. I have a small, above ground, 3,000 gallon pool. Do you think I could get away with only using 50ft of steel pipe?

[@likelydaily6767]

Firstly, I really appreciate you making this video and the details you went into. Great work. Last month I made myself a pool heater very similar to your own, only with a shorter 10ft 1/4” copper coil, with only a half-height oil drum with a steel lid with a flue. I only have a 10ft pool and it managed to raise the temp from 28 Celsius to 34 Celsius in about 2 hours. It was a fun project but I was left feeling that had I attached the coil to the top of the flued lid rather than wrapping it around the inner of the barrel that this would heat the coil more efficiently still. I found the flued lid helped increased the output a bit too. I’d be interested to know your thoughts on this. I plan on making a mark 2 soon.

[@netwrench6570]

How many holes did you have for air intake, and what size?

[@likelydaily6767]

Net Wrench I believe it had 8 holes evenly spaced around the drum, about 1” from the bottom, 25mm in diameter. But it also had a raised bottom plate which was a little smaller in diameter than the drum itself, leaning a small gap between its edge and the side walls of the drum, under which there were another circle of about 30 or so 8mm holes.

[@SGJamo]

Great video! Thank you so much for doing all the extra work calculating and showing potential results for other sized pools. I have a question: In your opinion, would this work with a saltwater pool? I know stainless is more resistant to corrosion than say copper, but will it hold up to the salt water over time?

[@moonshiner2977]

Are you thinking of heating up the sea ?

[@rodknocking351]

It seems that most DIY heat transfer inventors make the same erroneous assumption - that low exit temperatures mean the water is moving too fast to pick up heat. That is incorrect. The formula for heat transfer rate is: U * A * (T hot - T cold) - where U is the system heat transfer coefficient, A is the Area of heat exchange, and the temperatures are the hot side and cold side. As a general rule the HIGHER flow rate maintains the LARGEST temperature difference between the hot side and cold side, and the MORE heat you transfer in total. As someone else commented you also want high flow rates to maintain turbulent flow. The fact that the total heat transferred (flow X temperature rise) is quite similar in each case here just means that cold side flow is not the controlling factor in this system. I would guess the limiting factor is the stainless tubing which has rather poor heat conductivity, only about 6% of copper. Other wise neat video series. Seeing the heat output of one of these barrel heaters (about 1.5 kw) is most helpful for anyone considering building one.

[@memocontini]

obrigado

[@josephlarsen]

how much wood do you use to heat it for a single day? I've been thinking of doing something like this but using a rocket mass heater to capture more of the heat

[@deadlysharts7742]

There are a few thermodynamical and hydrodynamical circumstances you’re leaving out, but overall very good job. Biggest question here, is it worth the time and effort?

[@renaecampbell5780]

I'm wondering if your design without the holes, and the barrel filled with water and a fire built under the barrel would be more efficient????

[@famcontreras93]

Thx... but did you discuss the amount & cost of wood to run six hours

[@kencooper2059]

Interesting video, but I'll comment on a couple of things. Though you're definitely making the energy, the water temps you're generating are potentially dangerous. I would suggest using larger tubing or multiple runs to generate a higher flow rate with water not so hot. Your pump is a centrifugal design, so the sound change you are hearing is actually the pump unloading. It won't hurt the motor, but if you restrict the flow rate too much you could overheat the bearings. Unlikely though, so long as you are moving some water. Ideally, you would construct a heat exchanger that would carry the full flow of the 1.5" pool plumbing. But, that's hard to do in a DIY setting. You would likely have to use multiple circuits in a manifold design. Very complicated plumbing.

[@mrmadame28]

If you woulf use a second or a third coil in parallel, your 2 gpm limit would be pushed further and you could eventually push the full pump flow in yhe heater. Anyway, good job and thank you for sharing your work with us, much appreciated!

[@harunyahyadotorg]

excellent

[@paulpoisson4148]

What if you doubled or tripped the coil and hoses using the same barrel. Probably do 10 degrees in 3 hours?

[@michelkirsch2482]

The most important Informationen is the flowrate. Thank you for that... i always Was to bored to Do this Mathematik

[@accessiblecruisetravel-dre3383]

By opening the pvc valve aren’t you dumping water out of your pool which you will have to replace?

[@tameralaskaris6909]

To Jack on the Farm: what would be the thermal gain become by using 1/2” or 1/4” pipes in the barrel rather than the 1 inch pipe? Wouldn’t you have to increase the number of pipes in the barrel if you decrease the diameter of the pipes in the barrel? Would the length of decreased pipes in the barrel also become decreased?

[@alanmandragorian1776]

Great video. The math was definitely an added plus. Just wondering if a second coil around the outside would help? You’d reclaim all of the wasted heat from the outside of the barrel. It would be similar to a scotch marine, 2 or 3 pass boiler. I’d run run the pool water though the outside coil and then feed it to the inside one. In essence you’d be “Pre-hearing the water and you should get closer to 150 or 180 depending on the barrel temp. Your thoughts?

[@netwrench6570]

The answer is yes, though the efficiency is lower. Look up SSLDad's videos. His inside coil got gummed up, so he wrapped one (a very short one) around the outside and said it was working.

[@kennybanger]

Can u put a valve on the output and slow it down to heat it more

[@kyle8455]

If you use 200 ft of stainless steel would you be able to increase your result??

[@UnwellGaming]

wouldnt it work better if u used copper tubing? as that is a better metal to transfer heat to the water

[@rickandtish]

Great job I’m sure it’s above a lot of peoples heads but you still made it easy to understand. I’ve been struggling with ways to heat or 14,000 gallon pool. Currently I have my hot water pressure washer that burns diesel or kerosene running on a recirculation pump that is normally mounted in one of my service trucks for the pressure washer. I control the flow by the pump that I purchased which is 3 gallons per minute. I’m sure it’s a little bit less than that considering the drag through the coil. However the water coming out of my hot water pressure washer is somewhere in the neighborhood of 160°.My unit burns surprisingly clean however diesel is far more expensive than broken pallets. I’m hoping to get a 10° rise out of it. I will post another comment with my results. Any thoughts?

[@rickandtish]

By the way it’s just heating, I do not have any attachment on the end of the hose to create pressure

[@rickandtish]

Update. 12 hours later and 20 gallons of diesel burned it reached 89 degrees.

[@patriciasummers8881]

Thank you for the great video. I can do this! But I want to ask, could this conceivably heat the pool in the winter? My winters are average 35-45 degrees in December-February and I have an 18’ round pool 48” deep. I have adequate scrap wood so could I use your design or tweak it? I have work ethic but not the awesome mathematical ability you display. I am determined to swim in my pool year round! Thank you so much!

[@ashow13]

I don't think this would work in the winter unless you built more than 1 heater. With an 18' round pool you could expect the temperature to raise roughly 1° per hour without sun. My guess is the heat loss through the walls of the pool in the winter time would be around that, so you'd be lucky to even maintain the temperature of the pool.

[@netwrench6570]

@@ashow13 So I agree, though some of the losses can be mitigated with a good cover, and using foam insulation (such as the 1" panels) around the outside. I'm thinking of burying one side of my pool, though my is a Kayak with a steel frame.

[@349322]

@@ashow13 Thanks for the video, i have a 10000 gallon pool in the ground our winter is about 65 deg F... would it be possible to heat to 99 deg F if i double the length of coil ....

[@ajt51508]

How long before the temperature goes back down?

[@mirsadcupina3899]

The heat loss up to the pool should be great. The hoses should be insulated.

[@TractorguyinMass]

Do you think putting output of warm water in or by skimmer would make it warm quicker having tempered water to start

[@ashow13]

That would help to mix the water better. I noticed that by putting the hose on the opposite side of the pool that I created a hot pocket of water. When I went in to swim I could feel one side of the pool was hotter than the other.

[@adriancastaneda9088]

Can you wrap another coil so the water goes twice inside the barrel and ad a lid to the barrel? Isn't there a lot of heat loss trough the top?

[@netwrench6570]

I am in the process of updating my barrel after having tried wrapping the 100' stainless pipe around the outside (to avoid it getting creosote). I had also tried wrapping a 50' copper around the outside at the same time. Best I could manage was 30K BTU with intense fire. I got one degree (up from 67 Fahrenheit) only to lose it to a 44 degree night. I had wrapped the outside of the barrel with aluminum flashing to hold the heat on the coils, but I didn't measure the effectiveness, though I assume it helped. So what I'm planning on doing asap is have the aluminum coils on the inside of the barrel as Solo Engineer had (done), the take the copper coil and mount it at the top of the barrel, which has a lid with a flue. I'm going to cut a door on the side to fuel it. My problem was dealing with the large amount of coals at the bottom. Perhaps by having the coils in the inside, there will be better use of them. Any suggestions? I'm also going to put some standoffs on the barrel to wrap the flashing around the outside, to give it a bit of insulation. I had thought about burying part of the barrel, or putting bricks around the outside. I plan to get another barrel and have it on it's side, but since this one has all the air holes, it seems like it's better to start fresh. So, do you folks have suggestions for a grate or some way to minimize the coal buildup? I really need quite a bit of BTUs to make this work, and so far it's been disappointing. There are health reasons why this is important, but I can't afford a regular heater. Thanks for any help on this.

[@josephhiggins4036]

I am planning to build this for the summer and I can not find the coil, if anyone could link me it that would be great.

[@watchluver]

how much wood do you have to burn? What is the cost of the wood for an entire season? Maybe you can add this to the cost...

[@kdisha]

Nicely done calculations ! The only thing that bothers me in your setup- is such a waist of a burning wood energy- you probably catching up only 5-10% that could be used. I have seeing people use old car radiators placed on the top of the burning fire- much better heat exchange ( I know it has some issues too though).

[@ashow13]

Thanks. I'm sure a radiator would work okay at a low flow rate, but I'd be very surprised if it had the temperature and flow rate output of a 100ft. coil. I don't show it in these videos, but I do have a lid for my burn barrel so the flames aren't shooting out the top with all that heat being wasted. I'll try laying the barrel sideways instead of vertical so the flames shoot up toward half of the coil and see if that makes a difference.

[@ajt51508]

How long will it stay warm

[@hammadkhan83]

Pls tell the weight of wood you burned in 6 hours.

[@349322]

Thanks solo..... My pool is 10000 gallons built into the ground.... winter ambient temp is 65 deg F water and air. i need to heat the pool to 99 deg F. Is this possible

[@markweinhardt1855]

nodoby heats a pool to 99 degrees lol. That would just be nasty !

[@jjaybizzy2]

Can you do this with copper pipes they attract more heat so less work surely?

copper does not like chlorinated water!

[@jjaybizzy2]

@ yea but it’s like 25$ so you can change it every summer like it’ll be fine for 2-3 months atlest

[@23dt444]

Excellent video, but Your comment about the pump working harder pushing water through the 5/8 hose is inaccurate, if you reduce flow, the work being done by the pump is less, you can see this by measuring the amp draw at full flow, and at restricted flow, with the flow restricted, the amp draw will be less. Counterintuitive, but nonetheless true

[@peterdamico1722]

Why did you choose stainless over copper when copper is better transferring heat.

[@jeremygarman2464]

Copper corrodes more quickly and will get leaks fairly quickly - watched another video on here where someone found out the hard way. Additionally, once copper becomes heavily corroded the corrosion acts as an insulator and it loses some of its thermal properties while 316 stainless is less likely to do so. 316 stainless is also more resistant to chlorine corrosion as well.

[@ptt3975]

Great video. Very useful info. Suggestion: for another $100 we can really boost the heat output. Use a passive black hose solar coil to take the chill off the water prior to entering the barrel. Also, what about taking in the water from the pool area you just heated? This would increase your output temp for free. BTW, I checked ancient Man-Law manuscripts and it never says that we have to heat the coldest water first!

[@ericjovenitti6747]

So there’s a huge variable you’re missing here though and I’m not trying to be a dick but ambient temperature it will play a huge role in heat transfer of the water and I understand that the water and ambient temperature are going to reach equilibrium but ambient temperature isn’t constant so it’s going to either add or subtract temperature from the water

[@PoisonShot20]

About insulated the line from barrel to the pool, it will help a lot on loses due to ambient temperature. Also close the gap between coils inside of the barrel, and using smaller diameter tubing, as suggested by another smartie pants!😂 Still a you did a great job. I'm not picking or bashing your project, just adding ideas that created discussion and at the end we all benefit from. 🕊️❤️

[@irveagle1214]

what about burn bans?

[@TimK73]

Good question. At least here in NY, a burn ban does not apply to "campfires". Remember, again in NY, keep 15 ft from a structure and 3ft diameter.

[@NoName-lw2pm]

For that much why not just by a pool heater?

[@paulzedov8471]

Can't find stainless tubing can any one help

[@markweinhardt1855]

brewry supply stores would have some, or amazon, but why stainless? Why not copper?

[@Horner219]

Get another burn barrel...cut time in half

[@justicemagagane5737]

MATH!! NOOOOOO

[@racingsfun]

So 55k btu heater per hour if you guys want cliff notes. Natural gas would cost me about $.60 an hour to run a 55k btu heater. If i used an electric heater it would be $1.80 an hour to run. So the next question would be how much does your wood cost. ;)

[@ashow13]

Mostly yard waste actually. Or scrap wood from house projects.

[@Asta-wl8jz]

Look at all of the CO2 you are adding to the atmosphere just so you can enjoy your pool. KIDDING!!!