Moisture on refrig line insulation
Morning All,
I came home yesterday and noticed the framers are still working in the basement. I went down to chekc on them and they pointed out something they spotted, which was the tube insulation on the refrigerant lines had become soaked in water. I presume this is condensation from a cold line meeting with the warm and humid room air in the basemnt.
I had previously noted that this line, which travels to the attic, might have had a leak in it as stated by an HVAC company last year. They were not sure if it was the A-coil or the line, but I reported this fact this year to the new HVAC company prior to installing the new a-coil, condenser, and line segment.
I say line-segment, because instead of running a completely new line they re-used a portion of the existing line that was in the walls traveling between the attic and basement (apparently it was the correct size). But the segment running from the basement outdoors was new and connected accordingly.
I do have the HVAC company coming back out today (to finish installing the heatpump in the basement, but wondered how to address this new concern. I would not feel comfortable drywalling next month without address this concern first. I can take and provide pictures as necessary.
Replies
Some moisture is normal, but given the history you should have them do a pressure test on the system.
That is what I was thinking. I will offer to pay a discharge (recovered refrigerant), pressure test, and re-charge. I would hope this isn't but a couple of hundred dollars to do, but ...
I was referring to just checking the working pressures of the system. If there's been a leak it should show up.
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
Ahh, you would be correct.
Lots of things can cause what you describe. A common one is that there is not enough airflow across the A coil. Not enough airflow can be caused by lots of different things such as a plugged filter, fan speed too slow, coil too big, air vents shut off, ductwork too small etc etc.
Without proper airflow the refrigerant isn't "boiling off" and is going down the line.
Could be the Thermal expansion valve isn't placed or set right.
Or you could just have a leak in the pan. A refrigerant leak shouldn't cause that problem except..................
roger
It's not refrigerant. When refrigerant leaks it evaporates as a gas. It's mixed with a little compressor oil so residue could have oil in it but not water. If on the other hand you have chilled liquid water running through the lines, it could be a leak.
Paul
Suction lines (i.e. the big insulated one of the set) are cold. Should be betrween 40 and 45 degrees in a nomal system. IF there is any breach in the rubatex type of insulation, it will sweat constantly. Feeding an insulated suction line through walls (like from your basement to the attic) is practically impossible without tearing the fragile insulation. Typically, only the ends are exposed. A little condensation at the evaporator coil connection or at the condenser is normal and usual. Elsewhere, it could be problematic.
The lines were all run before the framer started soffiting those rooms. Anyway, the system is cooling. My upstairs computer room is a nice 71ºF with the thermostat set to 72ºF and the NOAA reports my outside temp at 93ºF.
Edit: And this is with two computers, a TV, and a high-def receiver going for the last 7 hours.
Edited 6/4/2008 3:00 pm ET by Nuke
Could be that it's nothing more than an unusual temperature differential due to the basement door being left open, or opened and closed ten times a normal day, with the crew bringing materials into the basement. I've had air conditioning coild ice up on a hot day when a new tenant was moving into one of my rentals, an 1,800 square foot house. The first time it happened, I blew $60 on a service call. My HVAC guy told me it was just the unit working w-a-y too hard to keep the house cool when all the doors were open getting furniture moved in. Now I've learned to expect it. It's only 94 in Albany this afternoon ! Cold snap.
Greg
So let me get a couple of things straight. If the line ices up, the best way to deal with it (immediately) is to shut off the AC until it thaws out? I have a segment of my cold line, about 3 inches, that is uninsulated from where it goes into the A-coil out. It's frozen up twice in two days (just had system recharged). I just cut a thick piece of foam pipe insulation and put it over this exposed section. Will that work? I also found that I had shut off a large supply vent into my front parlor, maybe that's reducing airflow across the A-coil?What gets damaged and how quick when you try to run with iced up lines? (My AC ran for about and hour the other night before I shut it off)
Ice on the outside of the line will not by itself cause problems (and, in fact, the ice will eventually insulate the line enough to prevent further ice formation). Generally, though, ice on the lines (that persists longer than the 3-5 minutes it takes for the system to stabilize) suggests that the system in low on charge or has blocked airflow. And if there is ice on the outside of a line there could be ice in the evaporator coil, blocking airflow and leading to a cascading failure.
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
I had several air supplies shut off to the front of my house over the winter while I remodeled. Just opened 'em up last night and so I'll see if that has anything to do with it.
The mention that blocked airflow might cause ice got me to thinkin'...
This is a new system, and partially new refrigerant line. The portion of the line with moisture on it is running horiztonally in the basement. The basement door is open, its 91ºF outside and probably around that in the basement with 41% relative humidity. Doesn't seem to be affecting the performance for the 2nd floor zone, but I'm hoping the moisture problem resolves itself when the time comes for drywall.
Maybe when the heatpump goes operational in the basement and the RH drops this will resolve itself, but who knows.
I would hope this isn't but a couple of hundred dollars to do, but ...
Me thinks you are dreaming... with R-22 near $10/# wholesale, the avg. unit taking 7#, and R-410A even pricier, ???
Your basement lines are likely no problem, just need better insulation.
IMO, it is foolhardy to ever put reefer lines inside a wall.