Page 1 of 2 12 LastLast
Results 1 to 13 of 24
  1. #1
    Join Date
    Jan 2008
    Posts
    89

    Installation concerns

    We just had a Carrier Infinity 80 system with a Performance 15 seer a/c unit and the infinity control installed, along with an american standard accuclean unit. Unit is upflow, accuclean on the bottom, furnace over it, bit of sheet metal over that to connect to the three supply lines.

    I have a couple of concerns that hopefully someone here can shed a little light on.

    When they installed the accuclean/furnace stack, it seemed that the accuclean box was sagging a little in the middle. The furnace is narrower than the accuclean, and sits somewhat to the right of center on the accuclean cabinet. When the installer went to put in the filters, they wouldnt fit. He pulled up on the middle of the cabinet and that seemed to straighten it out, filters went in, filter came on and worked fine. I had the feeling from listening to the two guys talking to each other that neither one had installed one of these before.

    After they were done with day #2, which was adding the a/c and installing the thermostat, the accuclean now comes on but doesnt ever "engage"...the LED light stays on but doesnt blink. I'm guessing they didnt properly connect the wire that tells it that the fan is on.

    In checking it out, it was a little hard to get the front door off the accuclean and to get it back on. Had to force it a little, and I see that the cabinet is again a little bit compressed, sagging in the middle a little bit.

    I'm concerned that long term this is going to be a problem. The installation guide mentions supporting the rig from the upper sheet metal, but they built this bottom up and I dont think its attached to the wall or ceiling except to join the top of the coil to the supply lines.

    Duct-wise, I failed. After they replaced a lot of ducts and SAID they did all the sealing in the crawl space and attic, I was getting a 30-32% loss. They said it had something to do with some supply lines to the kitchen and bath coming up into the cabinets ("they just cut a hole in the floor and fed the line into the cabinet and then put a grate on the front"). I can see what happened there, but I'm surprised its a 30% loss in the system from two cabinets. In pulling up some floor registers, I can see that theres about a half inch to three quarter inch gap between the edge of the sheet metal and the floor cutout. Its not filled or sealed. We've got 14 of those. Its a 20 year old 3 story, and theres plenty of supply/return ducting running through the interior walls where its inaccessible.

    A/C wise, the new Carrier Performance unit is huge compared to the old Payne 9 seer we replaced. The old unit was on a small slab that was starting to sink a little and left it a few inches below grade. The saleman mentioned "pouring a new slab over the old one to bring it up a few inches". The installers had a large plastic platform that weighed about 10-12lbs that they laid over the top of the old slab, and placed the unit on that. The plastic "slab" isnt attached to anything, and the a/c unit isnt attached to the platform. They also put the unit about 7" away from the side of the house, and I know you guys love that, but not a lot of choice since the ground slopes away from the house once you go past the edge of the old concrete slab.

    Any info on how this SHOULD be done to have it be proper and work better for the long haul is much appreciated.

  2. #2
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,302
    Seems to me you got a handle on what's wrong. What it takes to fix it ultimately will need to occur between you and your installing contractor.

  3. #3
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    "Duct-wise, I failed. After they replaced a lot of ducts and SAID they did all the sealing in the crawl space and attic, I was getting a 30-32% loss. "

    How did they determine this?

    Assuming it's refering to duct leakage,click here www.aeroseal.com
    Fix-A-Flat for your ducts,seals from the inside out.

    6" away from the wall on one side only shouldn't be a issue,as long as the other side are clear.

  4. #4
    Join Date
    Jan 2008
    Posts
    89
    I guess I'm looking for whether the installation done is reasonable and proper. The company I contracted with is a medium size business (45 employees), has a good reputation and they were the second highest bidder, so I didnt go with a fly-by-night or the cheap guy.

    I'm trying to avoid the situation of saying "I think this is a problem" and hearing "No, thats the way everyone does it and its okay." I'm a good handyman but havent ever done much with HVAC stuff. I'm no looking to pit the installer against the entire crushing weight of every internet expert, just trying to educate myself so I know where to stand.

    On the air cleaner, should there be something else supporting the cleaneffects box or should the furnace/ducting above be suspended to avoid putting pressure on it?

    I did a little more investigating on my ducts. On pulling up a floor register it looks like theres a sheet metal box set in a cut-out in the floor and nailed in place which the register drops into, and what seems to be a metal sleeve that the duct attaches to that then slips into a hole cut in the bottom or side of the box, and there are metal tabs bent over to hold the sleeve in place. Theres a gap big enough to stick a finger in around the box between it and the floor cutout, and there are gaps between the sleeve and the box about 1/6"-1/8" in between the tabs. Same with the two air return ducts. I opened up one of the ducts under the cabinets, and its got a piece of sheet metal on the floor under the cabinet, one of those metal sleeves poking up through it from the crawlspace, tabs bent over but rather badly, and I can stick my little finger into the gaps. The back of the cabinet has about a 1/16" gap between the cabinet bottom and the floor but it looks like theres plenty of space for the air to blow down into the crawlspace through the gaps where the metal tube attaches to the floor sheet metal plate.

    I'm assuming it would be better to seal those up. But would the 2 air returns and 14 registers account for all or much of a 30% loss? He said he was pumping 1600cfm of air into the main return and losing 500-550 of it. In a typical "I'll seal all your ducts" situation, is it common to tape or apply mastic to these gaps or is that above and beyond the usual?

    The contract language and conversation with the installer was pretty straightforward "We'll seal all your ducts to CF-6R requirements". Where does "the duct" technically start and end? At the flexible duct end, the box or all the way out to the register?

    On the air conditioner, is it pretty standard to just drop one of these plastic platforms on top of the old slab and put the a/c on that or is it better to have a new concrete slab poured over?

  5. #5
    Join Date
    Jan 2008
    Posts
    89
    Quote Originally Posted by dash View Post
    "Duct-wise, I failed. After they replaced a lot of ducts and SAID they did all the sealing in the crawl space and attic, I was getting a 30-32% loss. "

    How did they determine this?
    The guy sealed all the registers and returns with a sticky clear film, hooked a bungie cord through the main return (20x24), hooked a collar to that, taped all around the collar with the same film, attached a blower on about 6' of flexi-hose to the collar, and there was a large meter device with two tubes, one which went under the film of the 20x24 return and the other went to a floor register about 12' away. He used different size fittings in the collar of different diameters and varied the blower speed.

    Assuming it's refering to duct leakage,click here www.aeroseal.com
    Fix-A-Flat for your ducts,seals from the inside out.
    I had seen that but was wondering about its effectiveness. We have a three areas of the house with sheetrocked vertical boxes that the supply and returns run through. Based on the quality of the rest of the construction in the house I'm guessing the metal pipe inside of those isnt sealed between. Wouldnt it be easier to just tape up the areas easily accessible?

    My big concern about the latex/aeroseal products is any offgassing. My wife has asthma and my 3 year old has pretty bad allergies. I had heard that the aeroseal products produces a heck of a lot of paint-type smell in the house for days to a week or more. The asthma/allergies is why we decided to replace the old furnace for a new one, get the cleaneffects to help clean the air, and get the ducts sealed so we'd stop pulling in air out of the attic and crawlspace.

    So far, no joy.

    6" away from the wall on one side only shouldn't be a issue,as long as the other side are clear.
    The service panel is very accessible; there are some thin shrubs that were planted around the old unit for shading but I can push those over or tie them back for the service people to reach all sides. Whats going to be challenging with this is when I reside the house next year...I oughta be able to yank the old siding out but securing the new siding back behind the unit might be a little bit interesting.

    Thanks for your response. Any information helps me be a more informed in handling this situation and getting the best outcome for my family.

  6. #6
    Join Date
    Jan 2008
    Posts
    89
    One other tidbit. With the fan on HIGH setting on the infinity control, and in the advanced service menu, the unit reports a static pressure of .75 and in the LOW fan setting, its .21.

    Not sure what that tells me, or if thats good or not.

  7. #7
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Quote Originally Posted by cfb View Post
    One other tidbit. With the fan on HIGH setting on the infinity control, and in the advanced service menu, the unit reports a static pressure of .75 and in the LOW fan setting, its .21.

    Not sure what that tells me, or if thats good or not.
    Not the worst we have heard of ,but we would want it below .7 in high,plus what is it in cooling,with a wet A/C coil?

    If you seal all duct leakage,the static will rise,as all the air will now have to go thru the duct system.Can't tell how much as it depends on where the leaks are.


    Aeroseal really works,we have been doing it for over 5 years,can't speak to the effect it might have on allergies,but haven't had an issue.

  8. #8
    Join Date
    Jan 2008
    Posts
    89
    Not sure what it is when the a/c is on and the coil is wet. Its 40 degrees here right now! But certainly it wont be better.

    The installer put a 3rd air return in too. Guess the old system was wheezing pretty hard with just the original 2, but it had no way to complain about it.

  9. #9
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Quote Originally Posted by cfb View Post
    Not sure what it is when the a/c is on and the coil is wet. Its 40 degrees here right now! But certainly it wont be better.

    The installer put a 3rd air return in too. Guess the old system was wheezing pretty hard with just the original 2, but it had no way to complain about it.
    If you have a smaller tonnage cooling system,it may be better in cooling,we are in Florida so more cfms for cooling then heating.

    Adding the Accuclean increased the static,so the extra retun was a good idea to offset that,sounds like you could have them do a little more,and get the static lower,what you pay will be saved in fan motor wattage reduction ,over time,could be a long time,depending on the cost.

  10. #10
    Join Date
    Apr 2007
    Location
    Derwood, Md
    Posts
    142
    Quote Originally Posted by cfb View Post
    One other tidbit. With the fan on HIGH setting on the infinity control, and in the advanced service menu, the unit reports a static pressure of .75 and in the LOW fan setting, its .21.

    Not sure what that tells me, or if thats good or not.
    I think it also depends on the blower size, specialy when oversized. What is the size of the outdoor unit and what is the blower size and what are the BTU's.

    Don't look at the static when the fan runs, but when it runs in either AC mode or Heat mode.

  11. #11
    Join Date
    Jan 2008
    Posts
    89
    I'll check the static when the heat is on. I just checked it with the fan.

    This is northern california, central valley...its 100-110 here in the summer, but very low humidity.

    The unit thats installed is a carrier 4 ton 58CVX090-1-16 90,000btu unit, the outside is a 4 ton 24APA548A. The coil is an ADP PCT9660M-215.

    Didnt realize until I saw them unpacking the boxes that the coil isnt a carrier coil, but I'm not sure how much that matters or if the one I got is a good one.

    The third return was probably needed in the old system as well. One return is 20x24 but the box its in is only 3" deep (2x4 wall) and 4' tall, the other return is 14x24 and the duct on that is flattened out a little because its squeezed in between a low roof slope and the attic floor.

    I measured the watt usage and its pretty good. With the accuclean turned off and the fan on low, the unit was pulling 77 watts. 97 with the accuclean turned on. When heating on the first stage, it was between 130-180 watts. When I turned it off for a while last night to check the accuclean filter media and turned it back on a few hours later, it ran at the full fan speed in second stage heating and was pulling about 535 watts.

  12. #12
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Per the specs for the furnace 535 watts would be over 1.0 static,1210 cfms.

    Cooling cfms will be minimum of 1400 set for 350 a ton,so the static will go up,plus some for the wet coil.

  13. #13
    Join Date
    Jan 2008
    Posts
    89
    Thanks, thats high. At the end of the current fiasco, I'll look into the aerosol duct sealing. Whats the life expectancy of that sealing? Does it ever start to break down or shrink or is it pretty much a lifetime seal?

    I got some correlated numbers. On high heat I had about 350 watts at the furnace plug, thermo reported:

    Heat stage: high
    Airflow cfm: 1069
    Blower RPM: 936
    Static Pressure: .53

    With the fan set to high, no heating, i'm getting between 535 and 560 watts (wandering back and forth) and:

    Heat stage: off
    Airflow cfm: 1400
    Blower RPM: 1164
    Static pressure: .78

    With the fan set to low, no heating, 77 watts:

    Heat stage: off
    Airflow cfm: 597
    Blower RPM: 580
    Static pressure: .22

    I called the installer this morning and they're sending a couple of guys out tomorrow. He said the report he got was that the ducts are only leaking 21%, although the guy that was here yesterday said 30-32%. They're also sending out the HERS guy to smoke test the ducts.

    Are the numbers above decent or should I have them work on the returns a little while they're here?

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event