Inuslation on suction line

David,

Calm down, Bud.

He stated the last two feet. I had thought he was referring to the piping from the building to the condenser.

I know!

That’s why I reminded you! :wink:

I just talked to HVAC companies in CA and FL, and they pretty much agreed with David. This is how I’m describing it in that part of the House of Horrors:

                                       The concern with insulation missing from the AC suction lines is condensation. At the exterior, this condensation evaporates, so it affects nothing. The likelihood of damage resulting from condensation due to missing insulation depends on the climate zone in which the home is located and the location (inside the home) of the missing insulation.  Damage is more likely in humid climates, and in confined spaces containing moisture absorbent materials, and that have minimal air movement.

The loss in efficiency is very slight compared to a dirty condenser unit or dirty evaporator coils.

Ya picked a poor topic to discuss. missing insulation is to me more of a cosmetic issue. So did you ask those same HVAC contractors why they all install insulation at the exterior condensing unit when they first installed the unit . If its not so important why put it there in the first place.

Kenton the temp of the returning Freon is what helps to cool the winding’s in the compressor. The cooler the compressor operates generally speaking the longer its longevity. The shorter the exterior suction line is not much of a issue the longer the suction line and with exposure to 100+ degree temp shining on that bare copper the warmer the Freon to the compressor . I have a policy that I write up missing insulation where ever it was installed. I don’t make a big stink out it and most of the time it never gets replaced, sometimes it does

Well Charlie… most of us see it, so it needs to be addressed somehow. Cosmetic issue was what two out of three called it. None mentioned the returning Freon temp, though.

Not many of us still around that have 40 years experience working on those system;-)

Haha so that’s how its done! I guess OJ really was innocent.

No insulation on the suction line is one thing, but 2’ between the house and unit is not a concern to me in air conditioning.

If you compare the 4’ inside the condenser with high speed 130F air pulled across it…
And that pipe is not insulated by the mfg.

Come on Dave you know there is not 4 feet of suction line inside that unit and the two feet between the wall and the unit is no big deal unless its on the west side of the home besides it makes the job look like a amateur install.:wink:

I agree, but there is a perception and bad reporting that this missing insulation has a significant impact on equipment performance. And it does not.

As David said not a significant consideration outside as it was described, but as Charley said we report it … without making a stink over it…

It’s probably less then ten bucks to fix. It is also noted on the Termite report.

No, that is BS!

The only part of the refrigerant line that is insulated is the suction line. The suction line is downstream of the evaporator (which does the cooling). “Superheat” that occurs in the suction line is after that cooling coil and has no effect on the evaporator to cool.

Measure the temperature at the coil and then at the condensing unit. This temperature rise does not effect the operating temp of the evap coil.

The only thing it could do is to lower the maximum design operating temperature (the outdoor temperature when your HVAC unit runs at 100% capacity. Generally 95 - 98 F), but no where near 10 degrees. even at the reduced capacity, you will never notice it because the sensible heat ratio changes and lowers the latent heat and keeps you cool due to increased evaporative cooling.

They are not talking insulated vs. not insulated. They want you to remove and replace the insulation to save money. You can’t save money when your savings takes 23 years to recover and the unit won’t last that long…

This is the psychosomatic comfort perception I have talked about.

“Seems to be…” is not a measured condition. It’s a perception in your mind without basis. “I feel better because I think I did something…”