I had posted a few weeks ago about our 2 year old Lennox heat pump system not cooling our front to rooms (facing west sun) last summer and now again this year. The year the system was installed, it worked fine. Same A/C company came out and said we don't have enough airflow and they wanted to increase duct. I also had FPL come out for a duct test, no leaks. Well because of the design of our house, the installer couldn't put another (second) supply line directly from the handler to the one end of our house where we're having the problem, so they just rigged something and charged me $600. So it was warm here in FL yesterday, about 80 degrees. Part of my house was nice and cool at 75 degrees, front two rooms were hot at 80 degrees. In the summer they go up to 85-86 degrees, and I have to pull out a box fan and suck some cooler air from the hallway in, not that it helps that much. I'm going to talk with the owner of this company, as what they did the other day doesn't seem like it resolved the situation. I don't know what else to do. I guess we could call another company, but how do you know how to get someone with lots of experience. It really upsets me. I just want my house to cool right!
Here's what I see missing:
You said the first year the system worked fine, but afterward things went downhill. If the system truly worked fine in the beginning, what caused its performance to fall off?
The reason I ask that is that are you certain everything was o.k. in the beginning, or perhaps is it possible the problem has been there in this one room from the beginning but you didn't really notice it until spending time in that room on a hot day?
Of course I must ask if a proper heat load calculation on your house was ever done, with proper cfm's for the room in question. Doesn't sound like it at this point.
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.
Yes, I've always used both of these two rooms. They've been my office, and I work from home. I've had my office in both rooms over time. One room is warmer than the other by about 1 degree (no matter what room computer is in). Same room is always warmer. Even with our previous unit, the front two rooms were okay, a few degrees warmer than rest of house, but not 10 degrees (in the summer). We had a 3.5 ton heat pump previously, so went with the same thing when replaced, as it seemed to cool efficiently. I don't know if anyone ever did any testing. I don't think so. It's so puzzling what changed from one year to the next. One problem we did have was the system would just quit working. So the install company put in several new thermostats which didn't solve the problem, then tried a couple of new transformers in handler, then finally solved problem with a new circuit board in compressor. The problem was occurring during the period when the thing would shut down/not work, but we were so concerned trying to get the thing to work, I wasn't really pressing the "heat" problem. I just can't take another year of this, and too, I feel like the company ripped us off with what they just did, as I don't think it helped any.
Wow,very unusual.Air flow was "okay" now it's not at all.
1.What was done for $600?
2.Do you keep the doors open to those rooms,to allow air to get back to the main return?
3.What brand and models were installed?
4.What type of duct system,metal,flex,ductboard??
Doesn't sound like they were out to rip you off,what do they say when you call about the problem?Often times they may not be qualified to determine the problem or the solution.Give us some more info. and maybe we can find a solution.
I've run into a piece of loose ductliner in the plenum covering a duct opening partially or completely...has to be something weird like that if it did indeed work ok the first yr.
Or,the blower could be on a lower speed than high...but surely they checked that.
I know this may be dumb to ask but did you check the filter? Depending on the house it could get really plugged up not allowing much return air to get through. If they messed up with the installation they could always speed up the blower a bit higher ( assuming they put dampers on each supply) to get more air in the rooms. More info is needed though to really tell you what you can do.
It would also be helpful to know how much sun exposure were talking about here (size of windows), whether you use drapes or not, ect.
We've had one customer with the very same complaint, but the office was literally a greenhouse with three walls entirely windows from floor to cieling, no tint, no drapes, constant sun exposure and they kept the sliding glass doors closed cutting the room off from the rest of the house.
I had the same situation here last summer that bbk is describing. The short piece of flex duct that connected the return air plenum with the actual furnace had come completely off. It hadn't fallen down though, still hung from the correct place, just open 2 inches all the way around and since it was facing away from the catwalk in the attic I never noticed it even though I had been up there numerous times doing other stuff. The AC never worked properly upstairs until they found that. 5 minutes bending the tabs over properly to hold it together and a little aluminum tape and now my AC upstairs works great again and my electric bill dropped nearly $75 the following month!!! I was sucking 120 degree attic air right into the thing and it was running constantly and I was wondering why it wouldn't cool!
Sure sounds like something similar could have happened to your system. The supply running to those rooms has fallen off, or gotten crimped or blocked or something...
What was done for $600? They were going to run an additional supply line out of the handler to the one part of the house. They were going to cut the original supply at the end of the living room. Then the new supply would feed the 3 rooms, 2 baths and 1 master closet. We have a weird house, and there is a very small crawl space to run duct work down through; therefore, they were not able to run new supply line like they had planned. This crawl space is over a landing. We live in Florida, so we have a cathedral ceiling (no space above), so the supply line comes down through small angle of rafters, maybe 18" big??? After the landing, they decided to cut the old duct off and attach a larger duct. Then added a new junction box with all the room ducts attaching in different positions. Previously the junction boxes were metal cylanders with the ducts going to the rooms being directly across from each other, so two ducts coming off box for two rooms, then another few feet down, two more ducts across from each other. This guy thought by changing the ducts, so that they were not across from each other would do the trick. Well it didn't. So I think a few new ducts of Flex were installed. That's what we got for $600. Still have the nice warm rooms (just front 2 rooms).
2.Do you keep the doors open to those rooms,to allow air to get back to the main return? Yes, the doors are kept open all the time.
3.What brand and models were installed? Lennox middle grade line 3.5 ton heatpump, installed new in spring 2003.
4.What type of duct system,metal,flex,ductboard?? Mostly flex. There were some metal junction boxes (tubes).
The filter is changed monthly. We avoid the tight accordian type, as we don't want to mess with the airflow, but we don't use bottom of the line either.
Sun exposure is one window in each front room measuring 54" x 54", so square We have pull down room darkening shades that we pull soon as the sun hits that side of the house. There is also a mini blind on the one and a curtain in the other room.
Funny thing, and the puzzling thing, is that the first year this system was installed (2003) it worked fine, and our rooms cooled okay. Now it's just these two front rooms. This whole end of the house is coming off the same trunk line, so it is bizarre.
Anyway. The owner of the company, who is an engineer, is coming out next Tuesday. He is thinking about a booster fan and possibly moving the thermostat. I hate to be a problem customer, but again, hate to waste money and hate to have a hot house. My baby is in one room and my office is in the other, so important to stay cool in the hot Florida summer weather.
I would think if there was a problem in the plenum, as some of you mentioned, it would affect the whole house cooling.
FPL came out and was unable to pinpoint any major leakage in any ducts, so it really is a mystery. I hope we can resolve it somehow.
I had wondered if the fan on the handler was less efficient than before, but it's not a variable speed, and I'm sure the guy who just gave it the yearly service would have considered all that. Who knows. Hopefully the engineer can figure it out.
Thanks for your suggestions. Any others
I would install a zone system to control the troubled areas.
How many sq. ft do you have?
It must be a large house for 3 1/2 tons of cooling.
How far away is the t-stat from the troubled areas?
How tall are you Private???!!!!
Try this ,just to see:
Feel the air flow from the register in the warmest room,then remove the filter and see how much it increases.
What size filter and where is it located?
Your filter could be too restrictive,your coil and or blower could be dirty.Plus all the other things mentioned.
Let us know what they find.
House is about 1900 sq. ft. under air. The air handler is about 30-40 ft. from rooms that are warm. Tried the thing with the filter, no change. Will keep you posted as to the remedy.
I was wondering about if in fact termites eat insulation. If they are in my front walls and ate the insulation, that would make a difference in the cooling abilities. We have major termite problems in Florida. Anybody know if they eat insulation?
Keep ya posted
Haven't really seen termite damage to insulation either in the walls or on the duct system in my experience. Rats are a chronic problem though, especially to flex duct. They love to peal back the insulation on the duct system for the water, sometimes without putting holes in the duct liner itself.
It's possible because of this for no leaks to be found but air warming up through the duct as a result. I would think that would have been noticed if that was the problem though. Kind of hard to miss 4 feet of uninsulated flex.