Adding Heat Exchangers to Garage Solar Heater

I'm adding more heat exchangers to the solar heating system. This system captures the sun's energy in hot water, and sends it to the radiant floor in my garage/shop. However, the heat exchanger is the weak link. I'm going to upgrade it to capture more of the sun's energy.
Playlist, garage build: • Garage Workshop DIY Su...
Video, re-using PEX fittings: • Reusing Uponor Wirsbo ...
PEX Expansion Tool: amzn.to/2E8AyAH
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[@osamaalhawi550]

I am a mechanical engineer in the field of related industry for over 38 years, each step you made in this video, each work, each action, your voice comment & explanations were EXCELLENT, quite systematic, well-executed with engineering culture and sense, I don't know your name, I am in another part of the world, but I must say THANK YOU, really Thank you. superb.

[@alanmcrae8594]

Thanks for sharing this teardown of hot water heaters for their copper heat exchangers. I just never thought that a discarded hot water heater had any possible diy resources in it. Man was I wrong! Respect sir...

[@Tommen1957]

I respect guys who do stuff and not critisize others in the comments. And even more for admitting if something didn’t go 100 %. It’s all about trial and error 👍.

[@scidhumouse1007]

Dude!!! Never seen anyone ever sand copper piping as fast as you @ 4:46 lol! Great problem solving! Nice to see such creativity.

[@MrWilliamzhang2008]

great video. we have Solar PV Water Heater. It is a pressure system. compared to normal solar thermal collector, we do not need plumbing works on roof top. It can be used for home, hotel, SPA, jacuzzi, pool etc.

[@richardoakley8800]

One of the best systems I've seen involved a 10000 liter insulated tank in the ground filled with used engine oil.. the oil was pumped through the solar panels with a pv pump. The advantage of used oil was it could easily reach 170 degrees centigrade plus.

[@AchillesWrath1]

You won't get very clean taking an oil shower though. Doesn't taste very good either. lol

[@tillisross2246]

You’re a man after my own heart.

[@blaineanderson1744]

Some foam panels to your homemade tank would double the efficiency. Nice plan, hope it helps your set up!

[@WhatDadIsUpTo]

Overall comment: By creating a 2 inch thick concrete vault and lining it with high density polyethylene sheet, sealed with high temperature silicone sealant, you can build a reservoir, which holds vegetable oil, which is heated from your solar application and all you have to do is run one single pipe through it for hot water. One single three-quarter inch copper pipe running through a vat of oil at 600° Fahrenheit will make all the hot water you could ever imagine.

[@jamest.5001]

I'm about to start a project similar to this, I'm gonna need a heat exchanger anyway, I'm going to basically convert a wood stove, to a boiler, I'm hoping to have a separate storage of 200-400 gal.in a well insulated box, the actual boiler will hold a couple gallons at most, I'll also use excess solar, and possibly thermal solar also, but that will come later, also possibility circulate water from my tankless gas water heater, for home heat. It will also supply hotwater for kitchen/bath use, I can also use me DC generator to heat the water, using about 4x 48v elements, and probably a couple 120v elements, so my AC gen can heat water also, if you are making it, and are off grid, you may aswell have backups for backups, I hope to add radiant floor heating, along with the radiators, good ol video!

[@4Fatherplus]

Thanks David. I enjoy watching you design and build your projects. Keep them coming!

[@davidbateman5805]

Hi David, Nice job. If you fancy making copper coils from scratch its not that hard to bend copper pipe. The trick is to fill the pipe with salt or sand so that it doesnt crush.

[@omelay]

To encourage stratification the return likes to be immersed to 1/3 from the bottom into a diffuser running level with ground. To break the vacuum drill a small hole in the side of the return pipe just inside cover. 100% of my work is solar thermal.

[@michaelchamberlain4618]

I had one that froze up while running. Fixed it and added antifreeze and now works grate

[@tonythoreson]

love the solar thermal vids. i finished a large install last fall, 7 - 4x10 flat plates and 4- 30 tube evac tube panels with a 1300 gallon tank. it takes alot more to heat space than one would think.

[@DavidPozEnergy]

That sounds great. Do you have any pictures or video of your tank? I would love to see that.

[@buffalo_chips9538]

How big of a space are you heating?

[@DavidPozEnergy]

Hi Buffalo-Chips, I'm not sure if you are directing your space question to me or Tony, but my garage is 1,200 square feet.

[@WhatDadIsUpTo]

A quick note on soldering: If you will “wet wipe “your joint after you sweat it, it will come out shiny and clean and you can see if there are any protrusions or indentions, which may lead to future leaks. Wet wipe using zinc chloride to paste or “Johnson’s soldering paste “same thing. After you’re done, wipe it off with a damp rag and spray it with hairspray, let dry and it will last forever.

[@scidhumouse1007]

He could have just cut the pipe at the fracture and insert a small copper coupler. Wouldn't affect the coil's bend.

[@johnabuick]

I built a system like this but I had a 160 gallon stainless tank made with 120 feet of copper tube coiled up in it to extract the heat. I have 4 panels of evacuated solar tubes heating the water in the tank.

[@geethanganikumari7095]

johnabuick

[@flatrateus]

I seem to remember someone doing this years ago. He placed large stones in the tank which stored heat overnight.

[@cemasti4524]

@Winston Smith I concur. Said me, a Chemical engineer.

[@Ikbeneengeit]

Thanks for another video. One of the few youtubers who DIY but also do the math!

[@nlo114]

For security, your soldered-filled split tube would benefit from having a proper patch. Cut a piece of old copper tube (like a bicycle tyre patch), heat it to red and let it cool. It will now be soft enough to hand-form over the split. Clean it, tin it and sweat it over the split.

[@DavidPozEnergy]

Hi nlo114, Thank you. I didn't know how to make a patch. I'm definitely going to try your suggestion, sounds great.

[@sailingsolar]

I've had to repair far to many leaking copper plumbing pipes that had pinhole corrosion leaks. I'd cut out the section and replace with new pipe. To many times I've come to find MORE pin hole leaks would spring out from disturbing the existing pipes. I rethought my approach and changed it. I come to simply address the immediate leak by this method. Fix any leak in minutes. 1) Drain water from pipe. You can't solder copper pipes with water in them. 2) Sand paper or emery cloth clean the whole pipe 360 deg. and beyond on both sides of the leak. 3) Wrap clean copper wire ( stranded or solid) around the pipe with a solid layer of wire around the area. 4) Flux and sweat with solder over the copper wire patch and pipe. They become one and water tight. If you use solid copper wire (single strand) wrap it around the pipe edge to edge with no gaps and tight, then solder. That gives you added strength with a split like you had. cheers.

[@GB-kv6jw]

Actually you had it right in the first part. Once copper has corrosion and springs a leak on the pipe not a joint it is a sign of a failing pipe. Even copper has a life of 40 years all though it will usually last longer and I have replaced a lot in the most inconvenient places.

[@dgjvdgdlgccd9661]

عوت تقليم الكروم

[@nickwinn7812]

@@sailingsolar l Love your repair method. The split shown by david is typical for a frozen pipe though, not a corroded one. I'm sure your method would work well in this case also.

[@orcoastgreenman]

If you are still using this system, you could have the return dump onto an area separated by baffles, to allow the incoming water to stratify thermally and not disrupt the stratification in the tank. Matters more in a taller tank though. Reina LLC has videos on their superinsulated net zero, solar heated homes they buikd around huge 5,000 to 15,000 gallon thermal storage tanks. In my area, with milder, sunnier winters, I imagine I could keep my relatively poorly insulated 2600 sq ft house warm with a 1000 gallon thermal storage tank.

[@xoneeleven]

New subscriber here.... Thank you for speaking at a normal speed, and acting like a human being in your presentations.

[@DavidPozEnergy]

No problem. Thanks for watching.

[@xFiction16]

Hey David, loving these videos, I think it's super cool to follow. Would it be possible to do like an overview video where you talk about the theory of how everything is flowing and working together (thermostat, heat exchangers, tanks, pumps, and piping)? It's become a little difficult to follow with all the upgrades and stuff you've done! Again, love the videos!

[@DavidPozEnergy]

Hi xFiction, Have you seen this video? kzbin.info/www/bejne/fpyxcn-mqa6IeLs I give an overview in that one, but if you still have any further questions please let me know. I can always make another video to help out. Thanks for watching.

[@philipwinkelhorst934]

Hi David, Like your vids. But your water buffer would be much more efficient if you make 3 cambers. So you can have your heat exchanger(s) with your solar hotwater and one camber to collect the coldest water and one to have more buffer in between. And a lot of isolation if you like to use the energy somewhere else. But you can also make an electric heated part for when your batteries are full and the sun is still shining. You know I am still busy looking around for a green solution for my offgrid cabin on wheels. An "heat battery" from well isolated white-sand with an heating wire and an copper water heat exchanger in it.

[@jamest.5001]

I'd love to build my own house. I have a 1950ish house. no one lived in for about 20 years. now I have it off grid. so far a5kw inverter is plenty. I have a 8kw&2kw generator. with 25 gallon fuel tank just in case. I would like something like this. I don't know if I have room . I have my solar panels in the only spot I get good sun. I guess evac tubes would work. I haven't seen and with a good price.I love watching stuff like this.

[@DavidPozEnergy]

Wow, you are already off-grid! Nice! I can't wait to join you.

[@off-gridhillbillystyle3735]

I had to get a 10kwatt inverter just to push a washing machine..... What dose your 5k run?

[@brian6739]

To keep the cooler water at the bottom of the tank from mixing with the warm water at top, I would suggest to have the solar water return, splash on top of a rigid piece of insulation (floating in the water). The rigid insulation would allow the hot water to drip into storage tank off the sides of the sheet and create less mixing of hot and cold.

[@FixItYerself]

Nice project

[@scottmcintosh2988]

Brasso works well to clean brass and copper . Scott from N.H.

[@Dutch_off_grid_homesteading]

heya with a big garage like that it is nice if it's wormed up aspecaily wen you do it with solar collectors

[@chrisdick9860]

another idea is get an aluminum car radiator with a fan behind it and plumb it into that solar hot water setup you got and you will heat the air in that garage a heck of a lot faster

[@mihamaker]

Quick info... try not to splash hot return from collectors. Use water heat stratification. Connect that vertical central hot pipe in to a T with horizontal section that goes in the length of your tank, just below water line. Close the ends and drill more smaller horizontal holes in that section. across the whole length. Water will come even across the top of the tank over the coils. The point is that you disturb the water as little as possible, with hot water going in horizontal orientation. Bring the coils up as far as you can, also.

[@joebonsaipoland]

Put a server in there! It will host websites and heat your garage at the same time

[@zapwatt]

Thank you thank you thank you for saying "adjustable wrench" instead of Crescent wrench. It drives me bonkers when people interchange brand names with proper tool names.

[@joem1070]

Would have used some 3/4" to 1.5" gravel at bottom and the use of Uponor is great.

[@kentwilkens3435]

The thermal mass of water vs stone is about 4 to 1. Adding stone to a tank does not increase the thermal retention, but decreases it.

[@user-fr1lr4wu1p]

Thanks for your sharing. Looks like So easy.

[@benlyons7752]

Great job David. Clever.

[@marctorrades1760]

Well done David, simple system

[@DavidPozEnergy]

Thanks.

[@KayvanCrafted]

Nice built man👍

[@michaeljin101]

Expansion connectors new things to me, look convenient but wonder if they can be used under pressures.

[@catalinIntimidatorul]

Very nice work David. I also want to make the same thing.

[@DavidPozEnergy]

I hope you avoid some of my mistakes.

[@ThailandAmazing]

If you use a tall bow. The hot water be on top to use

[@royspeakman1157]

Great stuff !

[@brucerogers8281]

I have a solar water heater with a small drainback tank. Up on the roof I have two 4 x 10 panels. The drainback tank is small (either 2-1/2 gallon or 5 gallon) and is mounted towards the ceiling. The pump is near the floor. Also, there is a sight gauge on the tank. When the system is off (drained) the sight glass shows nearly full. When it is running the site glass is at the halfway mark. So as long as I can see water in the glass, the pump is still under a slight pressure and no chance of cavitation. In effect, I have about 8 feet of standpipe or an 8 foot column of water. The heated water going through the drainback tank flows into an 80 gallon storage tank with an internal heat exchanger (coiled stainless similar to your own heat exchanger). I'm guessing that when you had trouble with the cavitation that with the tanks in series, that you emptied the tank closest to the pump before you got drainback water flowing from tank 2 into the tank by the pump. Also, if the water drained down to within, say, an inch or so of the inlet pipe, that it may have been also sucking air. If they were in parallel, (plus mounted higher) it might have worked.

[@DavidPozEnergy]

Thanks.

[@Malibuair]

Parallel makes more sense to me. If you plumb it in series you are losing heated water to heat the next exchanger. I'm a sparky so I could be wrong.

[@arcticgreen-energy7353]

Because you have different lengths of inlet and return pipes the water will tend to use the shortest and least resistance path. All pipes should of been the same length to balance the system

[@tztz1949]

Yes, you need more storage. 500 gallons to start.

[@georgesiatos9848]

great work

[@DavidPozEnergy]

Thanks.

[@robertferreiro3466]

Thank you

[@drakevelazquez8728]

There is my first worm for the still

[@RogueOntheRoad]

Incase you missed the one that was done in Colorado and featured in Mother Earth News, a while ago... you can benefit from a tank that is about 4x4x8 lined with polyisocyanurate insulation... also you need to put an insulated cover on the tank.

[@TheRainHarvester]

RogueOntheRoad why the cover? Just curious.

[@simonac688.]

hi David i also enjoy your work...can i give u a few tips : the tubing should be colored red for HOT and BLUE for cold + u should put a Temperature gauge on each (cheap) +the rubber cover should use insulated panel with easy acces...Just saying :)

[@DavidPozEnergy]

Hi Beez, Thanks for watching. I love color-coding hot and cold tubes inside my house for the potable water. These tubes are all part of the garage heating system. I didn't think there are any part of the system that is always cold. But I'm not a plumber, just a DIY. So where would you have used blue tubes?

[@simonac688.]

or just put a colored tape thats what i do sometimes and im not a plummer also just a Heating and cooling ventilation humidification and general contractor....ect...loll

[@winnipegnick]

I think beez was referring to the Hot being the water coming from the solar tubes and Cold being the water being pumped back out.

[@mizaeleletronicareal]

Mizael eletrônica real paulista pe lingado nucanal valeu irmão tamos juntos valeu irmão

[@vilaometralha6146]

Nice but if your heat storage liquid is antifreeze or old motor oil it will retain the heat for longer

[@user-qx5rx2qq6l]

David, Thank you for your videos! Why do you need to use a heat exchanger? Why not just circulate the heated water straight into the radiant flooring? Thanks Bruce

[@DavidPozEnergy]

When I first built the garage, I made it with a sealed radiant floor and an electric "boiler". That system uses some cast iron parts. Cast iron can rust if exposed to air, so it's a sealed hydronic system without air. Later, I added the solar hydronic system to assist in heating. The solar is a "drain-back" design. This means there is air in the solar system. The heat exchanger keeps the air out of the radiant floor system. If I was building this from the ground-up, I could make the whole thing compatible with air by using only brass or stainless steel.

[@joeyork9891]

Nice work looks good too

[@markspc1]

Great job !

[@sams7655]

Do all of those flow equally? Seems like only the left one would flow and the other 2 wouldn't.

[@stephenmiller4324]

So heat transfer in is a product of surface area. Have you thought about getting old car radiators? A single one would have a higher surface area than all three coils if there is any flow across them. Older cars ~60-70's have copper core radiators if your worried about galvanic reactions

[@macsheadroom3209]

Nice

[@CalvinTaylor]

So you destroyed two perfectly insulated heat exchangers to make one big poorly insulated heat exchanger? Instead of building a new tank you could have used the two good tanks in series? Pex should bend so you wouldn't need all the 90's.

[@DavidPozEnergy]

Hi Calvin, I have another video up: kzbin.info/www/bejne/d4DMeYOFaLJmnac where I tried having the tanks in series and just couldn't make it work. That's why I resorted to making my own. Thanks for checking it out.

[@CalvinTaylor]

Right on, I admire your passion and resourcefulness!

[@unix-oq3cw]

if the exchanger is in the same room he's trying to heat then the heat dumped due to lack of insulation is fine.

[@longobardir]

I didn't understand that either?? couldn't the tanks be plumbed in parallel without taking them apart? I agree they don't need insulation and look better as raw stainless but insulation would help prevent a temperature gradient in the room.

[@DavidPozEnergy]

Hi Robert, Here is a video where I tried to make the smaller tanks work together, but had issues: kzbin.info/www/bejne/d4DMeYOFaLJmnac As for the temps in the garage, the vast majority of the heat from the water is given off into the concrete floor. There is so much mass in the concrete that the garage is very slow to change in temperatures. I don't have highs and lows. Thanks for watching.

[@tomkelly8827]

Hey David, are you using the hot water as hot water too? It seems like it would be more effective to just run the solar hot water through your floor directly. Perhaps you want to store it during the day and use it at night though? Insulating your tank and pipes should help a lot.

[@buffalo_chips9538]

Hey @DavidPoz you should have a look at a company out of Britain called SunAmp. Thermal storage using phase change materials.

[@nc3826]

Its good to see your over coming your problems one step at a time. But have considered using the fluid directly from the solar heating system and avoid the use of the heat exchanger and loss of efficiency? I realize solar panels need freeze protection and could get to hot to use with PEX but this those issues can be address without a heat exchange being used.

[@DavidPozEnergy]

I built the system over two years, so there are some flaws. The first winter I had no solar at all. I only heated the fluid with the electric resistance water heater (big gray tank in the corner). Then I started adding solar components as I sourced them. Things would be different if I built the solar setup in the beginning.

[@nc3826]

@@DavidPozEnergy Retrofits do add complexity. I would suggest you find a chat room that is far more specific to your project to ask advice about it but I get the feeling you want to do it you own way. So good luck getting it to work well enough to meet you needs. And as side note, I admire that your using PEX A with expansion fittings. Even with the added expense for the tubing over the cost of PEX B. And that cool but expensive makita expander. Since it wont restrict the water flow. Since the fitting have the same ID as he pipe. Unlike with other type of PEX fittings. And has a few other advantages to using it. Since I plan to do some DIY work at home, using a much slower but much cheaper manual expander or I may try to find a place that rents a makita expander.

[@onnobeckerhof5790]

Maybe it's me but why not just connect a big radiator and have the radiator as heat exchanger? It could be a closed system as well. Great video and construction.

[@DavidPozEnergy]

I know someone who did just that. It works good. If I had a radiator kickin' around I would have gone that way. Just using what I have.

[@onnobeckerhof5790]

@@DavidPozEnergy I think it's great and besides being smart to collect free energy it's also the creativity to experiment with available resources. Keep it up.

[@uvalueenergywetargetzeroco6719]

YOU VALUE ENERGY GOOD VIDEO

[@roymariano7116]

The best heat exchangers are not the coil type seen in your video. Consider replacing them all with just a single "Counterflow Wort Chiller" design, consisting of a tube within a tube, soft copper and coiled. This is positioned outside of the tank, separating the water from the solar array from the water used in heating the home. With this design, you could use automotive antifreeze inside the solar array and raise the boiling point to above 240 F if designed with pressure control, and this protects the solar array from freezing during winter.. I find that a 20 foot length of this type provides maximum efficiency. Refer to home brewing equipment sites for further ideas on this design.

[@MrMarioSupermario]

man you rock!

[@indigodragon7129]

Solar vacuum tube water heater retrofited to super heat gallium then use an electromagnetic pump to circulate the super heated gallium through a heat exchange coil that is in a insulated hot water tank. You could also circulate super heated gallium through a copper condensing coil then have a fan draw air through the coil to heat the air. Composting bins designed with aluminum rain spouts that have copper fined heat exchange pipe filled with gallium and placed in the center of the aluminum spout then snaked through three of the four walls of the composting bin that allows air flow through the aluminum spouts then insulate the bins. If done correctly you can have the Cooper fin heat exchange pipe filled with gallium to absorb and conduct the heat generated by the composting plant matter and then draft air through the aluminum spouts to heat a home green house or workshop. Cold air sinks hot air rises so it is possible to move air through the system without ths use of any electrical fans. 😉😊

[@DavidPozEnergy]

Sounds like a lot of work. Have you seen anyone try this?

[@indigodragon7129]

No one has done these ideas yet. I was brain storming and developed a central heating system using induction levatation that also heated water a cooling system that also generated electrical power. I only gave you the low technology version of the system. I designed a liquid air electrical power generator that uses superconductors from utilizing the ultra cold temperatures of the liquid air generation to increase the electrical output and with the use of vacuum spark gaps. The induction levatation of an alloy that super heats gallium with the use of high heat ceramic superconductors a central elemental heating water heating cooling electrical power generation system for a home green house and recreational vehicles designed to replace gas and diesel power generators. 😵😊

[@MattSiegel]

these are interesting ideas! a couple of things to consider: gallium is expensive. gallium will corrode the copper, and the released copper will form a compound with the gallium, raising its melting point. ... could an oil substitute for the gallium, and circulate naturally using convection (thermosiphon effect)?

[@user-ew1gf5pj1d]

👍🇰🇷👍한국에서 응원합니다.

[@erfanmedia6249]

thanks for this video👍

[@anjhindul]

A few things... one, why not use the other heat exchangers as they were? Those other things were better situated and better insulated... Then as for that 'turbulence' why do you have the hose above the water line? And if it is as I suspect, then get a funnel in there between the hose and the tank, the funnel bottom should be about 2" above the bottom and the rubber should be resting on the top of the funnel... But again, better to use the old heat exchangers...

[@davidharmon8073]

Cool.

[@gentlelove]

I don't see the link to the playlist. Where is it please? Shalom you are loved

[@bfbf3342]

What's "Sorder"....is that like Solder ?

[@BillyAlvarenga]

Very good videos Nice Repurpusing just gotta say if you would have just fixed the first one that you disassemble. you would have saved time and stress. Just by that error is why you where getting air in the loop right? @1:13 is the bad one the dark copper.. @3:06

[@DavidPozEnergy]

Hi Billy, Yes, the first one (dark coil) was the broken one. However, I'm not sure that would have solved everything. I was having trouble with the solar side of the system, not the radiant floor side. The break in the pipe was on the radiant floor side.

[@BillyAlvarenga]

Ok good, everything is working now Right?

[@DavidPozEnergy]

Yep. Although I have the system off at the moment because it's summer and no need for heat. But, yes, working correctly.

[@BillyAlvarenga]

Glad to hear that, I'm trying to do the same, but with both Heat and and cold solar system. Thanks For the videos learn alot here.

[@teejay622]

Wouldn't it be more efficient if they were in series? I'm asking. I'm pretty new to hydronics. Building a radiant floor in my pole barn. Thanks for posting this.

[@DavidPozEnergy]

I plumbed them in parallel because they are pretty narrow inside and will restrict the flow rate. By paralleling them the flow rate is staying good. However, if I was to build it all from scratch I would have just bought a coil of 3/4" copper coil. It would have been far simpler.

[@RobsTrucking]

All my neighbors have radiant floor heat in there buildings most are 40 x 60. Some are homemade systems some engineered none really work that well. One for neighbor has had several engineers come and make changes. He said it works okay but has lots of money tied up in it so much he refuses to say. He uses an on demand water heater and around $150 month in propane to maintain the floor around 65 degrees and never wants to open his doors. He has 8 inch fiberglass batts on the walls covered with 1/2 osb and 8 inch on the ceiling with a reflective foil bubble type on the ceilings. I spent $850 on a ceiling mount modine 250k btu to heat my 30x50 with 2 inch close cell foam R 15 on roof down to gables and walls 4ft then I have 2 layers of foam board insulation at 2.5 inches the 8ft down to the concrete floor i figure an r 9 on the walls and I put 1 inch foam on my doors r7. I keep it at 40 degrees and turn it up when I am out there working to 65 or 70 depending on what I am wearing. I have spent about $95 in propane a month for November until February. I wish I could have had the whole thing spray foamed that's where I would spend the money. As far as reliability you could always install a solar panel to run the furnace.

[@John-gm8ty]

would have been cheaper to have PV panels connected directly to heater coils and heat the water directly, but, half the adventure is working shit out for one's self and experimenting.

[@DavidPozEnergy]

You are right, if you buy everything at retail price PV would have been cheaper. I pulled my panels from craigslist. I have a video on it here: kzbin.info/www/bejne/b3_Hap5np7aDjZo

[@michaelwerbick]

Looks like immersion chillers to me....buy without destroying working units

[@TheZbadam1]

Probably a stupid question but why can't you run the water from the solar panels directly through the Radiant floor?

[@DavidPozEnergy]

You could! If you design the system from the beginning, and don't do it in stages with salvaged materials you can have the water from the floor run directly through the solar panels. This would even be more efficient. There are a few things to consider. First, with the system I have now, I could turn on electric heat in the 50 gallon water heater tank and heat the floor. This could be done independent of the solar altogether. That's a pretty nice feature. Also, if I spring a leak in in the solar system I can still run the radiant floor, heating the building, until the solar system is repaired. If I was to do this all over again I don't know if I would run the water directly through the solar, or still have a heat exchanger system. Of course I could design the heat exchangers better from the beginning. If I ever built this again with some other backup system (probably a wood stove) then I would probably run the system direct.

[@user-ew1gf5pj1d]

👍🇰🇷👍한국에서 응원합니다

[@rupe53]

I'm a bit confused by the way things are laid out here. First off, someone needed to do a calculation of the heat loss in the building, which will give us the BTUs needed for the system. Using that as a starting point, the loops in the floor get laid out based on size, spacing, and flow rate to maintain the design temperature. (floor and room) What you supply it with is the next step in the design, meaning: where does the warm water (heat source) come from? You have an electric water heater (not my first choice) and solar panels. Does either of them supply the necessary BTUs needed? (should have been part of design phase) It's likely the water heater is close but I think you will find that you need your solar square footage to be as large as your garage floor at minimum, and that's gonna be around 450 sq ft for a 2 car garage. IOW 14 panels of 4x8 dimension, which you probably don't have. You'd also be in better shape if you had several hundred gallons of insulated storage so you can draw from that at night or on cloudy days. Also, don't forget that a thermosiphon works both to gain heat... and it will give off heat at night. IOW, if you don't have something to stop the flow after the sun goes down your storage will cool off by morning. The flip side of the whole deal is what you are doing with the solar panels when not heating the garage? Do you have a pool to heat in the summer? Domestic hot water? Probably not a good idea to let the panels hot soak empty all summer. OTOH, you could install 10 - 20,000 gallons worth of buried cistern and slowly heat that all summer. Just a thought.

[@DavidPozEnergy]

Thanks for commenting. I have a video about the floor of the garage, shows the tubing, which might help answer some of your questions. kzbin.info/www/bejne/qWqznqdtjaySaMU Thanks for watching.

[@rupe53]

@@DavidPozEnergyYes, I have seen that video but it doesn't answer the questions of how much heat the building needs and what the flow / temp requirements are in the floor loops. My point being is that way too many people think a water heater or a couple of solar panels will supply enough, and that's not usually the case. If you don't have numbers to work with then you are shooting in the dark.

[@DavidPozEnergy]

Dear rupe53, If you are looking for lots of numbers, computer models, etc, then my channel might not be a good fit for you. I enjoy winging it and having fun in the process. I'm sorry I won't be able to help you.

[@rupe53]

@@DavidPozEnergyNope, no computer model but would like to know what you used as a starting point for design. Charts? Diagrams? Guestimate of heat load? I mean, it's ok if you used a rule of thumb type direction but even that would give you a baseline of the possible output of your floor loops. If I had to guess (not knowing the exact sq ft or volume of YOUR building, I would say you could possibly heat 1,000 sq ft with maybe 30,000 BTUs when it's 0 F outside, with a well insulated shell. You went way overkill on the floor so maybe bring that down to 20,000 BTUs, but that's still a stretch with a 30 gallon electric water heater. (16 - 18,000 BTUs max)

[@DavidPozEnergy]

Hi rupe53, The electric water heater has 4500 watt elements, or about 15,300 BTU/hr. This is more than I need, but I didn't know that for 100% certainty beforehand. I had a good feeling about it being able to work. I think at some point I found a rule of thumb for how many BTU's per foot of PEX can be dissipated into the concrete, but I don't remember. I just remember realizing that my 1000 feet of PEX was going to be overkill for 15KBTU/hr, so that was fine. I bought an adjustable circulator (Grundfos Alpha 2) so I could dial that in, but didn't know how many GPM was needed in advance. The building is 1232 square feet with 12 foot tall ceiling. Since building I have tried to find the BTU loss per hour by simply using adjustable space heaters running in the garage, and adjusting them up over time (weeks) until they could keep the garage stable in winter. It turns out 2000 watts per hour keeps the garage temp. stable in winter. or about 6,800 BTU/hr. The week I ran that 2000 watt load had an average indoor temp. of 60°F and outdoor temp. of 10°F. Since my exterior shell is 4192 square feet of surface, More is going to be out the doors than anything else since I super insulated the floor and attic. I hope that helps, but as you can see, I was winging it. If the one heating element wasn't enough I would have added another. I was OK with some uncertainty going into the build.

[@nickdannunzio7683]

Why don't you circulate the liquid from the solar collectors directly through the under floor loop(s)...???

[@DavidPozEnergy]

If I was building this garage with the solar from day 1, then I would. In my case I retrofitted the Solar onto the existing hydronic system.

[@rogerwhiting9310]

I would guess that heat transfers to black best.

[@illusiym-Force]

Is your self made tank heat resistant enough?

[@ThailandAmazing]

You are gonna use antifreeze right

[@garybarbourii8274]

Running them in parallel could result in preferential flow through one or two coils, and be less efficient. I would not do that unless you needed more flow volume than a single coil would allow.

[@davidbagley1783]

Aloha

[@mikemehlhaff1130]

Have you ever made a battery out of sand and was it very successful?

[@DavidPozEnergy]

No. I have two hot water systems that I've built. I've never built a sand battery.

[@mikemehlhaff1130]

@@DavidPozEnergy me and friend are going try it. The sand can get a higher temperature but not sure if the heating elements can take it.

[@joecanad7893]

question.... why not put a 1x4 frame that you mount rubber top to, so that you can remove easily? Just an idea to avoid the stapling...

[@DavidPozEnergy]

Hi Joe, Thanks for the question. You can certainly do that. I tried that on my first tank years ago. What I found was the water inside the tank turns to vapor and finds its way out through the tiniest gaps between lid and tank. Not a huge deal, but you need to top-off the water inside the tank often.

[@indigodragon7129]

You should look into organic carbon power cells and solid state graphene or graphite power cell and stirling cold and hot gas cycle engines. Engines can be designed with antivibration technology and use magnetic bearings on all moving parts so no need for lubercation. Hot gas cylinder heads heated by induction levatation of an alloy with the cold gas stirling cycle being fueled by liquid atmosphere generated by a helium sealed cylinder stirling cold piston. Look up these on you tube and watch the videos. 😊

[@bexxISM]

Is there any treatment you use for your reservoir of water? I'd like to try this to create a "battery" for hot water.

[@darthgbc363]

Why are you separating the solar heated water from floor heating system? If the heat exchanger was for potable water, than that would make sense.

[@DavidPozEnergy]

My solar system is drain-back.

[@alext8828]

My question, exactly.

[@thedudefromU]

David, why "exchange" heat in the first place? The fluid running in the thermal solar collectors isn't potable and the fluid in the garage floor isn't potable. So how about running the thermal solar panels directly through the floor? The floor becomes a heat distributor.

[@DavidPozEnergy]

If I was starting fresh I would do it that way

[@michaelspencer6523]

Only thing i get out what you say is only solar powered water heaters only.

[@demil3618]

40° is pretty hot. BTUs...? I‘d expect KWs. I‘m confused. Interesting project though.

[@MarkVincentConsulting]

Like your idea. What would you suggest to heat a Greenhouse that is 10ft x 12ft in winter to stay 50 degrees or above? Would your solar heated tank heat hot enough to run through a radiating panel baseboard? How hot is your solar water heating in winter --v- summer?

[@CuriousEarthMan]

Hi:) I hope I'm not interrupting. You might really benefit yourself from the science already known for your specific area. If you talk to "Cooperative Extension", a service of the USDA and your state's land-grant college, they may easily give you a BTU number you need based on your climate, your greenhouse construction, and plants to be grown. Then you can know how many square feet of collector depending on the collector type/efficiency, which they or others can help you find out. The idea is to get you in the ball park with numbers and costs before you spend money, unless you have things already just to try. As in: you can see right away if you will need maybe 100 sq ft of collector or 500. You have a temp target that is more critical is some ways than a workshop. By the time you see how much space hot water storage might take, you might want to build yourself a parabolic trough collector to store more BTUs in less space (hotter water or brine) Sorry for budding in! If you grow things, the ag extension service has lots to offer! It's their mission :)

[@michaelspencer6523]

I hope those cold water pvc pipes not got hot water or they melt. They white not smaler yellow hot water pvc

[@CuriousEarthMan]

Great video, thank you! First time watcher, and at double speed. If you are trying to heat the garage, would it help to add a liquid to gas heat exchanger on the return line maybe as a last collection step before the water leaves the garage? I'm talking about a radiator with a fan behind it, and maybe a shroud. Maybe a 12v fan from a car...an assembly, so you could possibly make it variable speed and thermostatically controlled. I learned some good stuff here from you. Thank you very much!!!

[@DavidPozEnergy]

If I further cool down the water, (with a radiator) then I won't have as much heat transfer into the floor. I want the mass of the concrete floor to get as warm as possible.

[@CuriousEarthMan]

@@DavidPozEnergy If you want max heat to the floor, you will need two or three tanks of ascending/descending operating temps, and much more "coil"/ surface area in the tanks for heat transfer, and also to agitate or circulate the water in each tank, as I see you do partly now. The bottle neck could be seen as the concrete and pex transfer rates. Since adding more floor tube isn't likely, tank storage has to take up the slack, like a bellows or flywheel. The downside of solar-hydronic is its space needs, but I think you have enough space. Three tanks, say, (each will find its range to operate in) with the water passing through each, getting hotter each time before going back in the floor. The reverse with the panel loop. The radiator idea was to take 'waste' heat out just before the water leaves the building for the collectors. Heat exchangers: coils like you had, flat-wound copper tube and back and forth parallel tubes...how about horizontal car radiators instead of the plastic pipe in the tank, or finned baseboard tube, with compatible metals? Any dialectric couplers needed in the system with the electric water heater in the panel loop? More water storage, and at different temps; more exchanger surface, more fun! :) And btw, what about a passive 'beer can' Trombe wall to add a little boost? Warm air can warm slabs too, and maybe you want to try one for a project to post :) I can't preach to you, just offering another pair of eyes.

[@CuriousEarthMan]

@@DavidPozEnergy For a quick test, maybe use an open head plastic barrel and whatever heat exchanger is most handy. You could probably use stratification instead of multiple tanks, if your column were tall enough with enough cross section (but then your coil would be custom made, most likely) I'm not sure doing it horizontally in the tank as you are trying is going to help a lot, though did it?

[@stevepailet8258]

Curious why you did not super insulate the box. a larger box would have made this a lot more EFFICIENT> Why because you are not trying to heat the water and it gets the water to hot.

[@DavidPozEnergy]

Hi Steve, Thanks for commenting. I didn't feel the need to insulate the box because this is only a space heating system. The box looses heat to the garage, where I want the heat. I consider it like a big radiator. Right now (summer) the system is off.

[@stevepailet8258]

in floor radiant takes a lot of heat to get the floor charged then it does not seem to take as much heat to maintain

[@sailingsolar]

Yeah, but is your goal to heat the garage or your living area? With a conventional home heating system one does not "typically" heat the garage too. This should be no different. You want to heat the living area not in your garage, right. Bad rational, imo. Seems like a poor reasoning to justify not being willing to spend the extra time to do the install thoroughly which would put more of the captured available heat where you want it, inside the living area.

[@DavidPozEnergy]

Hi sailingsolar, My goal is to heat the garage, not my house. On my property they are two separate buildings. I have a few videos on building the detached garage, but I suggest this one because it shows the radiant floor: kzbin.info/www/bejne/qWqznqdtjaySaMU Thanks for watching.

[@sailingsolar]

OK, That's much different. Thanks for that. Best wishes.