I found you on page 2, I Though the mods pulled you or something

Did you get a look inside the evaperator fan?
it doesn't take much to slow the flow. The freon pressure differential in some cases shows problems. But under the right circumstances it just don't show everything.

If the velocity is good. If the temp out the vents is good, It is time to look for other problems; clothes dryer vent, water heater vent.


keep us posted!

 

RP, May I suggest a couple of things, 1 look verry closely at air flow, no or low flow across the coil or condensor= no heat transfer, don't forget the condensor. 2 too much or too little refrigerant will drasticly affect cooling. You said attic, is it properly vented? What is the temp of the air going to the evaporator? Are there leaks in the duct work, before or after the evaporator?

Good luck, let us know what you find.

 

Again, thanks guys...

According to the readings, the fan is spot on with speed and power. I would assume that the air going into the evaporator is correct.

Also, according the HVAC guys, the condensor checks out. Refrigerant pressures are also said to be in the optimum range.

I'm still thinking evaporator... I need to remove the plenum - which will be a task -- so that I can get to the evaporator to confirm that the BOTTOM of it is clean.

EDIT: The temp of air going into the evaporator would be ambient in the attic - which is typically 10 degrees warmer than the exterior, IMO. In short, it's pretty darn hot air... How does one remedy a hot attic in a house that gets sun nearly all day long?

 

RP - isn't your system equipped with air returns from inside the house? My installing indicated that we could do several small returns or one large one depending on how big I wanted the registers to be in the floor.

You could always install a thermostatically controlled vent fan in the end peak vent of the house. That way you wouldn't have to manually turn it on and off. They even make solar powered ones now.

 

If you are drawing air from inside the attic, there's the problem right there. You need inside air returns, with those ducts wrapped.

 

Yeah... my bad, guys... the return vents are located on both levels of the house. Not from the attic... wasn't thinking when I typed that one up. It's been hell day #1 with work...

 

UPDATE...

The air is still not working correctly but, I think I helped to isolate the problem today. Observe the following:



I don't know if an evaporator should show any oxidation (rust) but, I obviously have some. Again, this is a 4 year old unit.




Popping off the top cap on the evaporator revealed that --- SURPRISE! -- it's full of blown-in insulation. Humph... wonder why I was getting such low air flow? This is something that two technicians couldn't figure out on two different trips to the house. I mentioned to BOTH that I had seen small pieces of insulation in the registers of the house and further noted that one of THEIR TECHNICIANS had removed insulation from the blower unit back in 2005. None of the three noted that the return air duct was loose and sucking up insulation. They all just pencil whipped it and said it was because I had a piano near the front of one of my air returns - total BS.



Here's a side shot after removing another panel. Note the furnace tubes beneath the insulation stuck in the evaporator. I pulled out about 1 cubic foot of insulation.




Now, here's my problem...

Despite removing all of this, I still have nearly no cool air coming out of the registers. I figure I either knocked something loose while I was in there that caused the system to loose the refrigerant or that I still have another issue. The system isn't freezing up and seems to be cold outside at the condenser. Further, I've noted that the fan on the condenser (outside) isn't really blowing air that is very hot. In fact, it actually seems a tad cool.

Note, it was 79 when I kicked the system back on (after nearly having a heat stroke in the attic)... the house is still 79 - this, 6 hours later. Ambient high temp outside today was 88 or so.

Thoughts?

 

Wow, that's a lot of insulation. Talk about your bad luck. Now maybe those expert HVAC techs can actually figure out the problem since you did their dirty work for them.

 

At least I'm not the only one who's had the great experience of AC problems! My home is a shade over 5 years old now, and I have dumped over $1700.00 in repairs into my AC unit during that time -- a new evaporator coil and compressor last summer.

With what you're describing (a house staying at 79-degrees despite the unit running continually) I can't believe a decent HVAC man can't diagnose something wrong with it?

I think the biggest issue you already are aware of -- a cheap, builder grade unit! Like the saying goes, you get what you pay for! I'm already budgeting for the day when I'm going to have to pull the trigger on a complete new system for my home. If I can eek another 5 or 6 years out of my unit I'll be delighted......

 

Yeah... it's a cheapo builder unit; the absolute minimum.

I just got BACK in to it (again after taking the pictures and removing the insulation from earlier) and about another 1/4 cubic foot was stuck in the evaporator.

My hunch is that the return line was just slammed full... I think it's out now. I turned the fan on and allowed it to run with no top on it... it snowed in my attic for about 5 minutes. Amazing the amount of stuff that came out...

The way I see this is that it's totally unacceptable. The company made note of pulling insulation out of the fan blower back in 2005 but no one really gave it much of a thought beyond thinking that the insulation guys probably got a bit wild with they're blowing and managed to get some in there. Guess not...

I plan to have a very serious, very direct, and very pointed discussion with them tomorrow. I expect help... free help. This problem occured (and was occuring) during the warranty period; it's just taken us this long to diagnose the problem and get it right.

BTW, should an evaporator have that much oxidation? Also, when I opened it back up just an hour or so ago, I noted that the evaporator was VERY wet. The drain is working but, it seemed unusually wet (outside temp is 74'ish with 70% humidity (but was closer to 80% during most of today)). Is that normal?

Thanks again, guys.

 

Keep bothering them untill

Sounds like a great srevice team that company has.

YELL louder. Actualy I don't yell , I like getting even

 

*bump*

 

Hey RP, isn't Openclasspro#11 who posts in the Chips and Tuners section an HVAC guy or is he a plumber. Can't remember. Might want to hit him up.

 

Rockpick,
No, i don't see a reason your coils should have that much oxidation. Maybe here in Tampa on the coast near saltwater, but gotta figure not much sea water near Kentucky. That is part of the problem, i would have to think, with heat rejection being a little out of wack with the rusty coils, which also if they are not leaking now, will be soon enough. Can't believe you had that much of the coil blocked with insulation. That should have had an effect on the pressure on the liquid and suction lines. Call the slack-jaw back that hosed it all up and show him the crap you pulled out and pictures, and don't let him out of the attic until it's fixed!

Good luck, brother!

 

Much appreciated, TPC. You're right, I believe he's one of the two... I can't recall either.