Can anybody estimate for me how much space I would need to take a 250 foot roll of 1 1/4 poly pipe and wrap it like the picture?
Anybody good at math out there?
- Thread starter MapleLeafFarmer
- Start date
If you want to do the math yourself this should work for a decent estimate for the diameter of the coiled pipe which would be one side of the square:
(PI/4)*(d^2)=250ft*O.D. (pipe)
d=sqrt([4*(250ft*O.D.)]/PI)
For schedule 40 PVC pipe with an O.D. of 1.66" that would result in a "square" of approximately 80" or a little over 6-1/2 ft.
1-1/4" IPS SDR11 PE4710 Black HDPE Pipe has an O.D. of 1.66" as well.
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Thinking about using some leftover pipe I have to add some heat to my pool. Most of my heat comes from a boiler now and as back up I have a air source heat pump.
I like your method. You got the right answer, but don't show multiplying 250' by 12 to get inches. Consistent units, you know
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I thought AI was taking care of that!I like your method. You got the right answer, but don't show multiplying 250' by 12 to get inches. Consistent units, you know
Based on an Xcel calc, the pipe would make about a 8-1/2' OD circle using an ID of24" (if you can do it that tight) 23 wraps of 1.66" pipe.
If you wanted to calculate it you'd simply add the square of the inner diameter (hole) in the numerator of the square root term.
So is a 24" diameter for the first loop reasonable? With the addition of heat you could probably get a tighter coil.
I'm sure there are more advanced ways to do it, but it's been a long time since math class. Since the late 60's most calculations for me have been related to electrical power. I took (for me) the easy route. Look up the pipe OD, figure that 24"Ø is about as small as that pipe wanted to be coiled (I battled a 300' coil of 1" ID when we built our place), added twice the OD for each successive wrap and left it up to Xcel.
Oops - As noted by McMXi there was an error in the sheet.
Oops - As noted by McMXi there was an error in the sheet.
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Some additional info for your project. I love this site but it has not updated in a long time. Still useful though
Arrgh. You're right. Although I SAID I added twice the OD - I didn'tLooks like your Coil D column increments by 1.66 rather than 3.32.
I THINK This one is correct (but I also thought the earlier one was)
The sad thing is ,after doing all that work, you won't get a lot of heat out of the collector. Very little surface area for the sun to heat up. BTDT 25 years ago. went with proper flat 'corrugated' panels ( 3 x 4x12 units ) to heat my 15' above ground.it'd easily heat to 84*F on a sunny day.
Years ago I saw an installation where the owner simply fastened his black pipe on the exterior of a South-facing fence. It ran horizontally in many rows on the wood fence. The fence was one of those made in sections with thinner horizontal pieces of wood giving it a woven appearance. That may provide more square inches of pipe exposed to the sun that making it into coils that could shade each other.
If you put the formula I showed above into Excel it's a lot simpler, cleaner and way more efficient. You can output any length, pipe O.D. and starting diameter by changing the values in thee cells.Arrgh. You're right. Although I SAID I added twice the OD - I didn't
I THINK This one is correct (but I also thought the earlier one was)
View attachment 175239
Of course, we're talking about very simple geometries here, but as the geometry becomes more complicated that's where calculus starts to become useful.
I used to enjoy listening to Click and Clack every Saturday and they'd have some interesting math problems. I remember a truck driver calling in and asking where to put the marks on a dipstick he'd made for the fuel tank to show 1/4 full and 3/4 full. The tank was a metal cylinder laying on its side which is typical for tractor/trailer type trucks.
The practical solution was to measure the diameter and length to get the volume, then add 1/4 the volume and mark the stick. Then add half the volume and mark the stick again but this time to show 3/4 full. The math solution was more interesting and easy to solve using calculus. I don't think I ever thought of a geometric solution but there probably is one.
The practical solution was to measure the diameter and length to get the volume, then add 1/4 the volume and mark the stick. Then add half the volume and mark the stick again but this time to show 3/4 full. The math solution was more interesting and easy to solve using calculus. I don't think I ever thought of a geometric solution but there probably is one.
That's cool but way beyond my Excel capabilities
I was also a fan of the Tappet Brothers. One of our VP's had an accent and sense of humor that would have let him fill in for one of them.
If you put a glass cover over it you'll get a lot more heat.
But at 8.5 feet in diameter, that might be a bit expensive....
But putting some insulation behind it will make a noticeable difference, too, and would not be expensive. Use 1" foam with a foil surface and you'll gain a lot.
But at 8.5 feet in diameter, that might be a bit expensive....
But putting some insulation behind it will make a noticeable difference, too, and would not be expensive. Use 1" foam with a foil surface and you'll gain a lot.