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Old 12-18-09, 12:56 PM   #221
NiHaoMike
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Except for the "HVAC girl" I talked about previously, HVAC engineers tend to be hostile to amateurs. They often claim stuff about safety, but that is a very weak argument since automotive repair is even more dangerous (plus a mistake in automotive repair is more likely to hurt innocent others) and every automotive parts store I've been to has been very willing to help with how to troubleshoot and repair just about anything on a car, even those that are safety-related.

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Old 12-21-09, 01:27 AM   #222
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Christian Nelson,

Thanks for your excellent report.

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Originally Posted by Christian Nelson View Post
New here, I have a propane boiler I installed myself this past year. I also installed my hydronic heating system, used slant fin's heat loss estimator, and sized my system. I have a combination of infloor radiant, and baseboards, using hot water. I sized the radiators to run at 140 degrees, so a bit large, but I was making the runs with PEX instead of copper, so I didn't want to run any hotter than 170, plus I wanted to augment with solar, so I wanted it to be as forgiving as possible.
So, where did you get your copy of Slant Fin heat loss estimator? I'm assuming you're referring to the Hydronic Explorer program.

Now that your into the thick of winter, what is your assessment of your combo-hydronic system? Is it delivering heat to your home as you had hoped it would? What kinds of things would you do different? What did you do that was really right?

Do you know what the 'degree days' are in your area?

How well is your place insulated?

Can you share details regarding your hydronic floor layout? Did you use a 'wet system' or a 'dry system'?

More details of the radiators?

The reason I'm so curious is that I'm about to put one in my place in a few weeks, and I'd appreciate any advice you have.

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Originally Posted by Christian Nelson View Post
Anyhow, I have had no end of fits dealing with HVAC people, the boiler I got, I bought from PEXsupply.com, and it needed to be fine tuned for optimum efficiency, and I don't have a meter. Well, I got the answer form almost every HVAC person "you bought it on the internet, have the internet adjust it for ya" and they wouldn't come out to do it.. So, I am buying a meter myself I guess.
Yeah, doing it on your own forces you to be a combination of scientist, a grunt worker, a pirate and a revolutionary.

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Originally Posted by Christian Nelson View Post
Anyhow, pretty happy with the system so far, and hoping to set up the solar shed with under ground storage tanks this summer. I found this DIY VERY interesting, and was thinking of maybe using a heat pump to keep my storage tank warm in the cloudy days of winter when the solar isn't helping much, and at best not using the propane boiler much.
Well, using a heat pump as a secondary heat source makes pretty good sense. If your are using a commercial air-source heat pump, you should be able to geat a COP of around 2.5 or better. I haven't to build an air source heat pump so I'm not so sure what a DIY could achieve... most likely 2.5 or a bit less. My experiments with water-source heat pumps indicate that a COP of 3.5 is a reasonable expectation. Anyway, if you pencil the conversions out, you'll see that either approach should be more efficient than propane.

A slightly different approach I am considering is to use the heat pump to extract heat from the water storage tank down to a point that would prevent the tank from freezing, in my area. Then the heat pump would switch to ground source heat extraction, until solar energy brought the storage tank up to some desirable temperature. This plan would have the advantage that the heat pump would chill the water that was flowing through the solar heat collector, giving the collector a larger delta-T, which will result in higher collector efficiency. The water-source switching can be done with electrically controlled water valves, which are used in the hydronics industry.

My tests indicate that the water-source temperature has a direct, positive effect on COP... the higher the temperature, the higher the COP. But only up to a point. If the feed temperature gets too high, it can boil the refrigerant prematurely and mess up the evaporation/condensation cycle.

So there's still work to do. BTW, I went to a local solar equipment trade show a couple of years ago and I told them about my idea of a heatpump-assisted solar collector, and everybody I spoke to got really excited... always a good sign.

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Originally Posted by Christian Nelson View Post
My question is about the deep well drilling loops, I noticed you made about 4 fusion welds to make the "U" to come back up, and was wondering why you didn't heat them up and bend them into a "U" instead. Maybe drill the hole a wee bit bigger.
I actually tried this before I build the fuser. I used a heavy duty electric heat gun, that was capable of soldering copper water pipe. Using the heat gun carefully, I was able to heat the poly pipe to the point where they would bend, but I was not able to get a smooth bend without the poly pipe collapsing. I also tried using a bending jig, but was not able to prevent the collapsing problem. I never did try filling the pipe with sand or salt before the bending... might work.

I can tell you that the fusing process is really pretty easy, and is incredibly strong. But as I learned, you need to be able to test every weld... very important.

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Originally Posted by Christian Nelson View Post
Or, I was looking at SC80 PVC, and simply putting "U" fittings and gluing them at the bottom I would think would work. We use PVC for sewer pipe, and other things under ground, why not this? Electricians have a sort of blanket they use for heating up PVC conduit (SC80) and you can make a fairly tight 180 once it is warmed up without kinking the things. Would this poly pipe you are using be similar?
I came across a page somewhere on the net that described some of the early ground-source work, and it turns out that the early efforts were with PVC, but that type of plastic was abandoned because polyethylene is more flexible and tougher, and the welding thing is not rocket science... it's not as simple as gluing PVC, but it can be learned by a mere mortal.

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Originally Posted by Christian Nelson View Post
Also, I very much agree with the insulate the nonsense out of your house thing.

I've been slowly injecting slow rise foam in my walls, zero insulation in them before.

I live in Wisconsin, with the frost line of 34" house built in 1908.
Oh, so you have one of the oldies-but-goodies too! I think there are several of us here at ecorenovator who are working in the same way on their old houses.

I really want to hear about the foam injection scheme...

Have you figured what the cost per cubic foot is?

Do you have any info as to the R-value of the foam?

My method of using slabs of EPS foam layered up in the wall is working, but it is a fearful lot of work.

Good luck on your project! Please feel free to ask any questions and share any discoveries you have along the way. And in case you haven't noticed, there are loads of people tuning into this kind of thing.

We're all in turn: scientists, grunt workers, pirates and a revolutionaries.

This is exciting stuff.

Best Regards,

-AC_Hacker
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Old 12-22-09, 08:24 AM   #223
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Wow, gave me homework already!





Quote:

So, where did you get your copy of Slant Fin heat loss estimator? I'm assuming you're referring to the Hydronic Explorer program.
I downloaded it off their site, I think yeah, it's called the hydronic explorer program, I did this a while ago, so I am not sure I can get all the facts straight, my bookkeeping is haphazard at best!

Quote:
Now that your into the thick of winter, what is your assessment of your combo-hydronic system? Is it delivering heat to your home as you had hoped it would? What kinds of things would you do different? What did you do that was really right?
Well, it's easily keeping the house at 70 degrees, at least on the main floor, it feels comfortable upstairs, but I haven't taken the time to check with a thermometer. Outside temp was in the teens, and around zero F for a couple weeks, but is now up to the lows in the teens, highs in the twenties.

What I did wrong.. Well, biggest one was not using oxygen barrier PEX for my infloor loops, and between base board radiators. I've worn out a couple of pumps due to corrosion in 3 years of use. I am not going to be able to pull the runs out of the concrete, so I am planning on replacing my pumps with bronze as they fail, and maybe trying to find a nontoxic corrosion inhibitor to add to the water. Another bad move was I trusted a solder joint that was blind, I saw it flow, and assumed it wen all the way around. Of course, it was right above the new boiler I installed this year, and it didn't leak until a few weeks after I had it all going great. It leaked on to the controller board, and burned it up before I discovered the issue. I ended up buying a new board for $400 (after I finally found a place willing to sell it to me) so ALWAYS check all the way around your solder joint. Get a mirror if you have to.

Quote:
Do you know what the 'degree days' are in your area?
I have that info somewhere in my house, I could probably look it up, but it's pretty tundra-ish. Think near Canada, and not on the coast. I am near the Twin cities of MN, I am just across the border in Wisconsin.

Quote:
How well is your place insulated?
Well, not at all initially. Empty walls, except for the north side, they blew in some loose fiberglass that seems to be doing absolutely nothing! I have slowly been fixing that. This whole project began with me deciding to jack up the house, and redo the basement. It used to be half basement, and half crawlspace. Every winter, the house would settle funny, and half the doors would'nt open and close properly. This has been happening since it was built I am sure. I was never able to keep the floors, or the rooms over the crawlspace warm, no matter what I did. It had an outdoor wood boiler when I moved here, and I was chopping wood all summer just to feed that thing. No furnace back up when I moved in. I had to monkey with the old oil burning furnace just so I could leave for a couple days in the winter. The wood boiler didn't work out, if I didn't stoke it every 5 hours, the thing would go through wood like crazy, and never really warm the house. My wife didn't like hefting the 3 foot long logs into the thing, and I am gone for about 12 hours every day at work. So, we bit the bullet, jacked the house up, it ended up being 3 feet higher out of the ground, and a much nicer clean full basement under neath. This project has taken about 4 years, and I hope I never do this again in my lifetime! I did most of the work myself, with my dad's help. We hired the heavy lifting out, lifting the house, digging it out, and the cement work, but I laid out the PEX myself, and everything else.

Quote:
Can you share details regarding your hydronic floor layout? Did you use a 'wet system' or a 'dry system'?
My hydronic floor layout is pretty simple, I have a mixing valve that keeps it under 120 F, and I ran 4 loops on top of 2 inches of rigid foam under 4 inches of concrete in the basement. I didn't bother with auto switching manifolds, since a boiler operator at the college I work at said if I went with the simple mini ball valves, once I found the sweet spot, I would be able to just leave them there, and the system would be pretty consistent. I also put 3 loops under the wood floor on the 1st floor, with the heat spreader plates crewed right to the bottom side of the floor. I then put the reflective bubble insulation under them, to keep the heat going up. eventually I intend to fill the joist spaces with insulation as well. I put a pump after the mixing valve, that is activated by a thermostatic switch in the basement. I placed the pump after the mixing valve, because when the system was an "open" system (I was still using the wood boiler that first year) the mixing valve would cause the water to bypass the loop all together if the water temp was above 120. Not sure what you mean by wet system, or dry system. There' water flowing in the PEX tubing, but I don't think that's what you are referring to.

Quote:
More details of the radiators?
Radiators, are just some generic baseboards I bought through Grainger. High efficiency, I used the calculations from the slant fin software to size the heat runs. Ended up with two loops, one for the main floor, and one for the 2nd floor. I almost forgot the 3rd loop is the in floor. When I did this, I converted the whole system to a closed loop, with expansion tank. I used a big well expansion tank, as my boiler consultant told me you can't be too big, but you can be too small. So I found that a well one is HUGE, and actually cheaper, if you can afford the real estate on your floor. they dot he same job. I use pumps, no valves to switch my loops on and off. Original boiler I put in was an old Trianco Heatmaker, I got for $50, and replaced the burner, and pump, and igniter, and it was ready to go. I had to open up the controller board because it had cold solder joints, and I needed to resolder the joints. Unfortunately, I had to dial it way back (operating temp on it was 210, way too hot for my PEX runs between baseboards) with an Aquastat, and I think it was running VERY inefficiently. Basically I was forcing it to short cycle all the time. I thought about putting in a massive storage tank, and things like that, but decided ultimately to replace it with a high efficiency boiler. The old one kept the house nice and toasty, but it sucked the fuel down, around 900 gallons of propane from October to December of 2008. I really have nothing to compare it to, besides this new boiler though, so I don't know if that was better than the bajillion truck loads of wood I was putting through it before all this.

Quote:
The reason I'm so curious is that I'm about to put one in my place in a few weeks, and I'd appreciate any advice you have.
I found the slant fin calculations for heat run size, and boiler size to be spot on. I was honest about my lack of insulation, and set it to have the water temp at 140. So far it was exactly right. We will see as I improve my insulation how it may change..

Quote:
Yeah, doing it on your own forces you to be a combination of scientist, a grunt worker, a pirate and a revolutionary.
Lots of stress too, when your kids have red hands and faces from it being 50 degrees in the house, because you screwed something up, and your wife not saying anything, but you KNOW what she's thinking..


Quote:
Well, using a heat pump as a secondary heat source makes pretty good sense. If your are using a commercial air-source heat pump, you should be able to geat a COP of around 2.5 or better. I haven't to build an air source heat pump so I'm not so sure what a DIY could achieve... most likely 2.5 or a bit less. My experiments with water-source heat pumps indicate that a COP of 3.5 is a reasonable expectation. Anyway, if you pencil the conversions out, you'll see that either approach should be more efficient than propane.
Well, that was why this caught my eye so quickly, was it was a water to water system. I want to directly heat the storage tank, from the ground loops. 130, even 90 degrees would be enough, if the solar isn't keeping up. I am thinking about still running the baseboards off the boiler, and splitting off the infloor stuff off the solar/heatpump augmented system. Maybe running a third infloor zone on the 2nd floor. I figure, I should be able to run exclusively off solar for most of the fall and spring, and it should keep the boiler from firing as much in the winter. The heat pump shouldn't be even needed much, other than a few days of the year, which is why a cheap old window AC unit would be just the thing.
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Old 12-22-09, 08:25 AM   #224
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Quote:
A slightly different approach I am considering is to use the heat pump to extract heat from the water storage tank down to a point that would prevent the tank from freezing, in my area. Then the heat pump would switch to ground source heat extraction, until solar energy brought the storage tank up to some desirable temperature. This plan would have the advantage that the heat pump would chill the water that was flowing through the solar heat collector, giving the collector a larger delta-T, which will result in higher collector efficiency. The water-source switching can be done with electrically controlled water valves, which are used in the hydronics industry.

My tests indicate that the water-source temperature has a direct, positive effect on COP... the higher the temperature, the higher the COP. But only up to a point. If the feed temperature gets too high, it can boil the refrigerant prematurely and mess up the evaporation/condensation cycle.
Interesting, I never really thought about this.. Then I wouldn't have to dig any trenches, and I would be able to run the system as one, instead of splitting it. I will have to do some serious thinking about this!

Quote:
So there's still work to do. BTW, I went to a local solar equipment trade show a couple of years ago and I told them about my idea of a heatpump-assisted solar collector, and everybody I spoke to got really excited... always a good sign.
It is an exciting possibility. How hot is too hot though? I am fairly certain that most solar systems shouldn't get above 150, mine will probably never see north of 120, except for summertime.


Quote:
I actually tried this before I build the fuser. I used a heavy duty electric heat gun, that was capable of soldering copper water pipe. Using the heat gun carefully, I was able to heat the poly pipe to the point where they would bend, but I was not able to get a smooth bend without the poly pipe collapsing. I also tried using a bending jig, but was not able to prevent the collapsing problem. I never did try filling the pipe with sand or salt before the bending... might work.
OK, even with a jig, it was collapsing, must be thinner walled than I was thinking.

Quote:

I can tell you that the fusing process is really pretty easy, and is incredibly strong. But as I learned, you need to be able to test every weld... very important.



I came across a page somewhere on the net that described some of the early ground-source work, and it turns out that the early efforts were with PVC, but that type of plastic was abandoned because polyethylene is more flexible and tougher, and the welding thing is not rocket science... it's not as simple as gluing PVC, but it can be learned by a mere mortal.
Yeah, to me, there should be no reason you couldn't use PVC. I've seen it used for under ground water stuff all the time around here. As long as it isn't exposed to solar radiation all the time, it is pretty robust stuff. But that goes for many polymers.


Quote:
Oh, so you have one of the oldies-but-goodies too! I think there are several of us here at ecorenovator who are working in the same way on their old houses.
Yeah, 2 reasons (I may be wrong of course) I don't like people moving out, buying small chunks of land from a farmer, and building up a bunch of houses around here. Bugs me everytime I see another development spring up, or another McMansion being built in a cornfield. So, I decided to just buy an old farm. Place was built in 1908, has an old barn, that needs work, and some other out buildings originally on 40 acres, but I ended up with only 15. Couldn't afford the whole property right off, and when I was set to buy it, some city guy bought the rest and built a gigantic place out behind me, it has since been foreclosed, and sat empty for several months now. Really regret not being able to buy the whole 40 acres. But, I didn't have much choice. So, now I get to look at this gigantic house, and stupendously big horse barn (with indoor arena) right behind me that made my property taxes go up. The town folks figure that if my neighbor could afford to build a $700k house, I must be rich too I guess.. Anyhow, the other reason was, I was getting married, and I wasn't gonna make my wife live in a tent while we build our dream home..
Quote:

I really want to hear about the foam injection scheme...

Have you figured what the cost per cubic foot is?

Do you have any info as to the R-value of the foam?
Yeah, it's standard slow rise kits, around $700 for 600 board feet shipped to your door. tigerfoam.com is one there are others that sell these kits. It's VERY expensive, but it fills the wall solid, R6 per inch is the claim. I don't have to tear out my lathe and plaster walls, I just drill some holes every stud space, every 3 feet high, pull the trigger for 15 seconds, plug the hole, and go to the next. Plug the hole is very important if you don't want to see the playdough noodle factory flying out of your walls. I've been slowly doing this every year, one 600 board foot set. I have actual 2x4 walls, so 4 inches should give me R24, give or take. BIggest benefit I have found is ZERO air infiltration. I have also been doing rigid foam in my basement walls. Almost done there. 2 inches. I plan on reroofing this summer, with steel panels, and I am going to put the fanfold insulation under the roof, and according to the foam people, if I spray foam directly to the inner roof of my attic, I don't need to vent the attic space, I then plan on majorly insulationg the nonsense out of the underside of the roof, and making the attic into useable storage. I have never understood why we spend so much time and effort trying to keep the elements out of our houses, then punch holes in the roof to vent our attics. Then we pile a ton of insulation on the floor of the attic, so you can't even use that space! We will see if I have a mold problem. I plan on checking that.


Quote:
My method of using slabs of EPS foam layered up in the wall is working, but it is a fearful lot of work.
Yeah, not to mention trying to figure out where to put all that lathe and plaster (with lead paint) and breathing all that dust while you are tearing it out (did I mention lead paint getting kicked up?) I like to leave dead dogs lie, the walls are in good shape, not crumbling, I want to leave them as intact as possible, so I don't have to deal with the disposal of that stuff.

Quote:

Good luck on your project! Please feel free to ask any questions and share any discoveries you have along the way. And in case you haven't noticed, there are loads of people tuning into this kind of thing.

We're all in turn: scientists, grunt workers, pirates and a revolutionaries.

This is exciting stuff.

Best Regards,

-AC_Hacker
I am less scientist, more techie (that makes tons of mistakes, but tries to learn along the way) but yeah, this is exciting! I am thankful that there are people out there who do the stuff I do, but take the time to document and make sure things are accurate, unlike my off the cuff approximations, and hand wavy calculations
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Old 12-22-09, 08:48 AM   #225
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Oh, forgot to mention, the new boiler is only consuming 400 gallons, where the old one used 900 gallons of propane.

If that trend continues, the new boiler will have paid for itself in a year and a half.

Now, that may be because I was seriously not running the old system right. But, I have talked to others around my area, and 2000 gallons a year isn't out of the question for most, so what I was getting last year, seems to be average for my area.

I also was wrong about the frost line. For footings, it's 42" to up to code, around me, the water pipes and sewers that aren't 6 feet down freeze if you don't have good snow cover in January.

I have a poorly updated blog about my house project located here: http://nelsonics.blogspot.com/

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Old 12-23-09, 03:05 AM   #226
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Christian Nelson,

Just a quick reply, I'm getting ready to leave town for a few days, so my time is short...

Wow! Sounds like you're really taking the bull by the horns! Yeah, I think you're on the right track with the insulation. I like the idea of zero infiltration. At some point you may need to consider a heat recovery ventilator, if your house gets super tight.

Regarding heat pumps, the reason I got into building mine is that I couldn't find a water-in-water-out unit that was less than 4 Tons (1 Ton = 12,000 BTU/hr). It looks like your weather conditions are quite demanding, compared to mine and your house is larger too, so you may be able to find a unit already built that would work for you, in the 4 Ton range or larger.

Don't know if you read the part of my blog where I talked about using electric heaters with Kill-A-Watts attached to get precise real-time heat loss measurements. Don't know if I'd try that on a house as large as yours, but if you could measure the amount of propane you actually use an a per hour basis, as temperature fluctuates,it would be very useful information for future heating calculations.

I found that the Hydronics Explorer program over-estimated my heat requirements by about 50%, which is really quite close.

So, if you are able to keep your house warm with feed temperatures of 120 or less, you'd be a good candidate for a ground source heat pump, because that's pretty close to the limit of the present technology. The Japanese are working on Carbon Dioxide vapor-compression units which will reach higher temps. Some units are entering the market already.

So the feed temperature is important. Better insulation means lower feed temperatures, less firewood, less propane, less Tons of HVAC, as I'm sure you know already.

I think your wife deserves a shiny golden trophy... not every wife would survive such a major upgrade adventure such as your family is on.

Kudos to all of you!

Best regards,

-AC_Hacker
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Old 01-01-10, 11:25 AM   #227
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ac hacker, I have been skimming this epic thread of yours trying to find out where exactly you got that heat exchanger, I'm going to do something something similar for my ac in the house, and this will be a whole other thread but I think I'm going to add one on these to the fridge first and use the waste heat to preheat my hot water.
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Old 01-02-10, 01:15 AM   #228
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Joe,

Welcome to the conversation!

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ac hacker, I have been skimming this epic thread of yours trying to find out where exactly you got that heat exchanger, I'm going to do something something similar for my ac in the house, and this will be a whole other thread but I think I'm going to add one on these to the fridge first and use the waste heat to preheat my hot water.
I searched around for various kinds of heat exchangers, even went so far as to make my own tube-in-tube heat exchanger, but that's another story. I came to realize that it's possible to obtain a very efficient type of heat exchanger called 'brazed plate', for less than the cost to make one.


If your circulating fluids are clean and in closed loops, you should have no problem with 'fowling', which seems to be the biggest potential problem with brazed plate heat exchangers.

If you try to buy them from a reputable outfit that is in the business of selling heat exchangers, you'll have to pay with your arm, your leg, and your first born...

However, if you do a search on ebay and use a term like "brazed plate", you will find many people selling them, some at prices that are sure to fit your budget.

The next problem will be to determine the size you need. In this post, you'll find a discussion regarding selecting a heat exchanger, or in engineering, "sizing" a heat exchanger.

I plowed through quite a few web sites and poured over many tables and created this formula:

Heat = ((width) x (length) x (# of plates - 2)) x 1950

[* NOTE: a previous version of this formula had 5000 as the last term. Subsequently I have come to realize that the formula overstated the capacity if the heat exchangers, and I have changed the multiplier to 1950, which produces more reliable values *]

...where:
  • Heat is in BTUs
  • width is in feet
  • length is in feet

You might need to play around with it a bit to get what you need.

So for instance, if you hooked a Kill-a-Watt to your refrigerator, and found that when it was running for several minutes, it was consuming maybe 400 watts, you'd convert the watts to BTUs like this:

BTUs = Watts x 3.412 = 400 x 3.412 = 1364.8 BTU

So, you want a heat exchanger that was at least this size or larger.

If I looked on ebay, I see a small 10 plate exchanger for $45, not too bad.

It is 7.52 inches long = 0.6267 ft

it is 2.87 inches wide = 0.2392 ft

Plugging that info into the formula I created goes like so:

Heat = (0.2392 * 0.6267 * (10 - 2)) x 1950 = 2338.54 BTUs

This would be nearly twice what I need, so the heat exchanger would work well for my project.

The particular heat exchanger in the link has this fitting info:

Fittings Available:
All 4 ports: 1/2" Male NPT
All 4 ports: 3/4" Male NPT
All 4 ports: 1/2" Female NPT
All 4 ports: 3/4" Female NPT

All 4 ports ... NPT means that it is pipe thread on all connections. This is good for water, good for beer, but not so good for refrigerant, which spends it's life searching for ways to escape.

The kind of connections you want on the refrigerant side are called "sweat" fittings. which would suggest sweat soldering, but remember that refrigeration connections want to be brazed.

If you keep searching, you will find the size you want, with the connections you want, at the price you want.

Good luck!

Best regards,

-AC_Hacker
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Old 01-02-10, 04:24 PM   #229
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Great info as usual, I can find the NPT ones all day long, but the problem I'm having is finding one with sweat fittings. I didn't know if you had found a good supplier for them or not.
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Old 01-02-10, 06:54 PM   #230
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Originally Posted by Joe View Post
Great info as usual, I can find the NPT ones all day long, but the problem I'm having is finding one with sweat fittings. I didn't know if you had found a good supplier for them or not.
I think the supply of heat exchangers to the ebay folks is variable. There stuff pretty much all comes from China and is very good quality.

I don't know how carefully you searched...

Did you try searching the supplier's "store" in addition to the ebay posts?

Might help.

If you find a supplier or two or three that seems reasonable, you might even send them an email... never hurts.

They just might have exactly what you want, or it might be coming in soon, or maybe they could order it for you.

Long as you're at it, you might see if they can get a 5-plate exchanger, since the 10-plate was over-capacity. Could save you some money too.

As a final desperate measure, you might try to make your own heat exchanger, probably not brazed plate, that's pretty sophistocated.

But check this one out:


Soft copper tube inside soft copper tube, the picture tells the story... This style is called tube-in-tube.

It would be a real crap shoot knowing how much tube to use. You could always make one and just try it out. A lot of good stuff gets made that way. If it was me, I'd start with five feet of tube.

When I tried my first Brazed Plate lash-up, I had no idea if it would work or not, I just hacked it together and tried it out. Worked good. Then I studied up on capacities and all that and found out that I could hardly have been closer.

Best of luck!


Regards,

-AC_Hacker

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Last edited by AC_Hacker; 01-02-10 at 08:40 PM..
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