hi,
i am in the process of installing a pond loop. my engineer says that i do not need to bury the feed and return line to the pond very deep nor do i need to insulate the top of it as i would if it were my drinking eater line. he says the antifreeze will take care of that. even though i have my line burried 4 feet (close to maximum depth of frost) i would think the eccomomic benifit of Sm insulation on top would help reduce heat lose?? has anyone seen information on this?

thanks

Going deeper and adding insulation is not needed, but will give you some benefit. The question is is the cost worth the return. If you are doing the work yourself, then it might be worth it. If you have to pay some one, then probably not.

Where are you is the first question. 4 feet a tad shallow in MI, but with antifreeze above ground would still work. Insulation over the top in my area would be a double edged sword that would impede solar gain.

My guess is that 4 feet down the soil temp in winter won't be a heckuva lot cooler than the pond.

Throw some pipe insulation on it if it makes you feel better, but don't expect a substantial increase in COP by doing so.

good points. Here is my theory, The one line will be @ lake temperature, with my pond loop under 4 feet of ice it will be 4.0 degrees C. The return line will be colder. How cold, I don't know but with a climate master 5 ton unit (one i have) I can guess about 0 degrees or a bit lower. given that, won't that cold return pipe tend to effectively pull the frost down? if so, then the feed pipe which is 4 degrees gets cooled down by this? ( i seperated the pipes in the trench by about a foot thinking that was good idea). So, insulating would be good???

but,
at 4 feet down i am currently below the frost line and will the heat in the ground win here making the frost not be pulled down and the insulation ineffective?

just wondering if there are studies on this or theorys because i sense that the feedback says it aint worth the cost. i am doing all this by myself

Supply and return lines tend to differ by no more than 10 degrees

thanks

everyone i have spoken to thus far about my pond loop application tells me to keep the supply and return 10' apart

Distance down....Distance apart.....Insulation......All about diminishing returns. Operational cost comparisons help in choosing. Generally we would have supply and return in the same 5' trench but rarely insulate aside from DX installations or external issues (water or drain lines...tree roots...utilities etc.).

I simply don't envision much 'crosstalk' of heat between 2 tubes less than 10 degrees different from each other. If both were copper and brazed / soldered together, then yeah, maybe so.

A pair of plastic pipes < 10 Deg F delta-T a few inches apart won't exchange enough heat to worry about.

thanks for all the support. i have began to bury. the lines are about 12 inches apart, 3- 4 feet deep, no insulation.
next step is the instalation of the hydronic system to utilize my....hot water. different forum i'm thinking

HEY I AM INSTALLING MY SLIM JIM TOMORROW HAVE YOU COMPLETED YOUR INSTALL?
WHAT DID YOU USE FOR ANTI FREEZE, I AM THINKING ABOUT USING RV ANTIFREEZE OR POLYPROPELENE
JUST CURIOS

not done yet

Prop is a good choice in the right amount. Too much is a bad thing.
J

prop is rated for -50 but i figure i only need it to zero. i bought 50 gallons of distilled water and 24 gallons of prop making my mix 30% prop, does it seem like i have it covered?

You really only need it to 15°. Most heat pumps will not function below 20°. The more glycol you have, the harder it is to pump. With glycol, using more than you need is not a good idea. What is the coldest you figure your loop will ever get?

Distilled water is not the best idea.

Think of it like a vacuum. Nature abhors a vacuum. That distilled water is ready and willing--even wanting--ions/impurities from other sources. It is almost a corrosive environment, because the water is able to collect extra materials. It's going to collect it from somewhere. Pumps, fittings, etc...they'll be giving their material to that water.

the climate master factory is who told me to use distilled water in my loop? what else would i use?

Regular, clean water. Not full of iron or sulphur, or sand, but clean water. Not distilled.

I concur with Dewayne 30% seems high.
J