I'm getting close to needing some insulation on my pipes in my HVAC project.  I've got a water to water GSHP dumping into a buffer tank and the tank feeding
an air handler for A/C.  The pipes are copper and will sweat a great deal when chilled.  The previous installation had some insulation on the pipes but all this did
is hold the moisture on the pipes.  Some of those pipes were VERY VERY corroded green after one season.  I'd like to prevent that by wrapping the pipes with tape or
something similar prior to adding my insulation.  Is this done, and if so, what type of tape?

Or is there a different method to waterproof pipes?

Thanks

You can go all nuts with ceramic paint blah,blah, but even a cheap acrylic kan-o'-krylon or similar formulated for use on metals will do pretty well (and WAY better than tapes) if you clean up the pipes a bit first. Clear coatings give you a better view of what's going on than pigmented paints, should any corrosion get started underneath the coating. Something like this would do it: http://www.krylon.com/products/acrylic_crystal_clear/

Spray urethane clear coating used in automotive paint apps is probably overkill and 2-4x the money, but will also work fine.

Copper only oxidizes a few mils and then stops. unless u have left over flux on in then it will continue untill all the acid or copper is consumed. Just clean the pipe with acetone or paint thinner and insulate with closed cell armaflex. They have seem sealer that you need to use with it. This is the way it is done professionally. Eric

Currently, I am building a house that will have six manifolds and require supply/returns to each manifold. I'm thinking of using closed cell spray foam to insulate the supply/return lines to each manifold. This may be something for you to consider.

I don't even know where to get armaflex. How do you handle valve and pump transitions?

Pipe insulation is a trade unto itself, If you have a Johnstone's store in the area they will handle it. Grainger has some. you need a very sharp fillet knife and you form flat sheet to pump and valve bodies. 1/2" flat sheet comes 3'x5' and the pipe is sold in 6' lengths by pipe od and insulation thickness. ie 1" copper would be 1 1/8" x 1/2" then you glue all seams with the armaflex glue. It is a time consuming task and a considerable part of a piping job...Eric

Sounds like I'll just paint the pipes clear and put on low cost insulation best I can. I can put a drip tray under the majority of the pump / valves.

I didn't mean to discourage you from doing it Eric

I'll still do it, but won't go to the lengths I've seen some folks do it. There's a few youtube videos on it.