You COULD dunk your rig in oil if you plan on cooling sub-dew-point.
Regardless, never forget the catastrophic powers of freezing water in lines. (I.E. Ice forms as a crystalline structure that expands, and as you know, destroys pipes, etc.) LoL good luck! Awesome work--it's good to see more progress. This should prove itself a very rewarding luxury.
Those crystalline ice structures detach old sediment in my iron water supply pipe every time it gets cold. Bless the Culligan filter company.
Since the pumps under 75w now, with more load on it, I'm planning on running it 24/7. I don't want to use antifreeze (less flow, less thermal conductivity), and might not legally be able to if I extended the outside loop (buried mechanical fittings) as discussed in...
Coiling the sun warmed pipe was quite easy. Once the first few loops are formed with the correct height, they can then be stood up vertically making further coils easy to size and secure. The coiled up slack piping can simply be "walked" down the line to the work area and quickly sized up then zip tied. When the slinky assembly got too cumbersome to support vertically , I moved it and rested it on the side of my house.
Slack coils down the line, the smaller the better. (Don't uncoil the piping like I did. Also when you do, remove the tie straps one by one. They're staggered so each strap frees a shorter length of the piping.)
A bit over 20 feet of 3.8 feet overlapped coils. I didn't need to make the overlap that tight but directly connecting the loops like that was fast and easy. Some of the far right coils need to be undone to run the return line back along the coils to meet up with the trench to the house.
It hasn't rained in days yet water has collected in the bottom of my supply/return trench. This ground is going to be WET.
My first knife screw up in over a decade. Pro-tip: use wire cutters to remove tie straps. Now to keep my left thumb clean and dry for a couple days. That's what I get for cutting towards myself, on the LAST strap.
So anyway, going down the hill and losing half of my piping to non-coil use wasn't part of the original plan. Visually seeing that has got me thinking.
If I could start over, I would've spent more on a 500 foot 1" coil and possibly used 1" PVC under the house. The head loss would've been lower resulting in more flow at a lower velocity. That would be extremely helpful for running a loop like this off weaker a pump or two. 18 feet of 1/2" ID PVC or 4 feet of 3/8" ID has the same friction loss as 500 feet of 1" ID pipe. 3/4" (garden hose size ID) is the sweet spot for flow, flexibility, and cost. This is why I didn't go with small refrigeration tubing.
On the other hand, pipe insulation for 1 inch ID piping isn't as commonly available. Something could be cheaply hacked together for a short supply/return line and if only coming directly up into one room. My 5/8th walled insulation hasn't shipped yet, probably in the next two days.
Right now I'm strongly considering buying a $30 100' coil of 3/4" black pe water piping and using it in the trench to the house. That's 100 more feet of cooling, a huge percentage increase.
I'd couple the loops near the surface so it could be checked up on or fixed if it developed a leak. With such low pressure in the loop I'm sure it'll be fine. Black PE water lines are pipes are coupled with barbs and clamps at pressures multiple times higher.
The Iwaki is now using 73w with my PC's three water blocks restricting it. I still have 10 feet of 7/16th tubing going to my PC, which is causing some unnecessary restriction. The filter will definitely be removed later too. I'm already further down the pump's curve than I want to be. Still no leaks.