Do you recommend insulating both freon lines on heat pump for when the flow is reversed in heating or cooling mode?
Jeez you are just full of questions today:D We don’t insulate both lines here and I don’t recall every observing any MFG addressing that situation. Lets think about it a minute in the heat mode your liquid line flow is toward the outside unit hot gas traveling toward the inside unit. I saw your pic of the two lines inside one insulation tube. Heat always travels from hot to cold the liquid line will be much cooler than the hot gas line thus loosing some of its heat to the liquid line by simple contact which is intended for use within the A-coil. My simple deduction would be you want no contact between the two lines in heat or cool mode. That is my story and I am sticking to it.
It’s not Freon, by the way. It’s “refrigerant”.
Im curious as to why there are two liquid lines? Is there some kind of heat recovery system integrated into the heat pump, perhaps to augment the water heater? But in answer to the original question, no, Ive never seen or heard of anyone doing this either. The vapor line would be absorbing a lot of the heat from the liquid line which you do not want.
One is the thermostat wire.
As for insulating lines, the liquid line is always the liquid line in a HP.
It is never below the dew point so it does not need insulation. The reason for the insulation is to keep it from sweating, it has not real job in the thermal loss aspect.
The only time we insulate two lines is in refrigeration. The suction line is connected to the liquid line and is used to cool the liquid line to increase evaporator efficiency under load changes.
[quote=“dedwards, post:4, topic:33109”]
Im curious as to why there are two liquid lines? Is there some kind of heat recovery system integrated into the heat pump, perhaps to augment the water heater? But in answer to the original question, no, Ive never seen or heard of anyone doing this either. **The vapor line would be absorbing a lot of the heat from the liquid line which you do not want./**quote]
Doug only in the cool mode would that occure in the heat mode your large line or the hot gas vapor line would be the hottest of the two lines and you would not want any heat transfer from the large line to the small line as you want to transfer all of the heat possible at the A-coil not in the line set in between the two units. Yes Dave was right there is a thermostat wire in the pic that if one does not look close hard to tell.
Mister Funderburk Freon/Refrigerant is splitting hairs yes we know brand names:D:D
Yes David is right also, the liquid line is always the liquid line or the small line but it reverses flow and the vapor line or big line is always the vapor line either hot or cold but it also reverses flow depending on the Stat mode
David,
You are right, one is the thermostat wire and its the biggest one Ive ever seen. Looks just like copper until you look real close and see the swirl from the wire twisted inside the outer casing. Most of the ones I see are so wimpy, and typically dry rotted and hanging on a thread. This one is a lot cleaner install than most I run across.
Looks like someone ran the stat wire inside 3/8" soft copper which I have done several time when the dog chewed the wires.
Of course I could be wrong, I was one time before. 
The liquid line seems to be kinked where it first turns up from the unit. Is this a problem? Would it restrict the flow?
I think they used the insulation as a protectection going through the wall is it insulated under the crawl space also?
I think the kink is just camera perspective.* was also looking at that. *
A suction line kink is much worse than a liquid line kink.
It had better be!