New Installation Going on Right Now - Pics and a question or two
I'm in the middle of an install of a new system that started yesterday. They finished the furnance/heat pump combo for the first floor. Seems like they're doing a good job so far. They used the existing ductwork, but I got them to mastic seal everything up for me, since it wasn't done back in 87. The old return was 20 by 8 rectangular sheet metal, and it was very loud. I asked what they could do to quiet it down. They replaced the basement portion of it with 16 inch flex duct. Pics below. Yesterday, they only had the low stage on the heatpump hooked up, but I couldn't even hear it running, which is nice. Any upside or downside to flex return done in this manner?
The original return made a couple of 90 degree turns to get around the water heater. The flex just bends around it, but goes up and down as you can see in the pics.
You're moving more air through the 16" flex verse the 20"x8" duct, which is good, but where is the furnace filter?
Furnace filter is in the grill on the first floor. The flex connects to 8 by 20 rectangular duct which goes to the first floor where the filter is.
Originally Posted by George2
Model numbers of the furnace and the outside condenser please.
A good HVAC tech knows how, an educated HVAC tech knows why!
It sounds like they left some of the 20"x8" duct that's against the wall, with the filter grille right on the other side, and tapped into that. What size is the filter grille? It'll be the size of the filters you use in it.
Originally Posted by breenemeister
Main Floor: Goodman GMVC950453B furnace, CAPF3636B coil, and a Goodman DSZC160241A
Originally Posted by heaterman
Upstairs: Goodman CHPF3636 coil, MBVC1200 variable speed blower, and a Goodman DSZC160241A, 10KW heatstrips.
That's correct, but the filter grill is on the first floor and the furnace is in the basement. The grill is 20 by 20. There's an 8 inch pipe off of top of the 20 by 20 grill that goes to another 12 by 12 grill in the stairway. So there is a total of 544 square inches of filter surface area. I've seen you guys say 200 square inches per ton minimum. This is a 2 ton HP/ 45KBtuh furnace system. This kind of combo return used to service the whole house. It was extremely loud. The new upstairs unit is also a 2 ton and it will have a 20 by 20 and a 14 by 14 filter grill. However, it will have separate return runs. I looked in on the installation at lunch time and it's looking pretty good. These guys started at 8 AM and by 12:45P they had basically replaced all of the ductwork in the attic and mounted the new air handler and coil. They hadn't put the returns in yet. They were outside and had just finished running the line set up to the attic.
Originally Posted by George2
Fine by me.
Originally Posted by breenemeister
"Better tell the sandman to stay away, because we're gonna be workin on this one all night."
"Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."
"Just get it done son."
Well, everything's finished and I need to schedule the inspection. They finished the whole job in two days. Most of it looks very good and it's cooling nicely so far, but it also hasn't been hot, so hopefully it'll heat up this afternoon so I can tell for sure. I have noticed a couple of what I think are issues and I'd like to get your opinions. I haven't fully inspected the attic work, but I've looked in the basement.
The first issue I see is that the coil pack is not lined up square on top of the furnace. One corner hangs over the edge and the other is recessed from the edge. It looks like it's sealed on with silicone caulk. When the unit runs on second stage cool, you can hear lots of what sounds like air leaking out and/or being sucked into the furnace. There's one place where quite a bit of air shoots out. Also, the furnace is dented in. See the clickable thumbnails below. Please let me know if you think this is an issue that needs to be addressed.
The shot above is taken from below so you can see the amount of overhang.
2nd issue I see is upstairs in one of the new supplies. I had them put a return in the master bedroom. The bedroom has a vaulted ceiling and with the bathroom and walk in closet combined is about 12 by 24. There are 4 supplies. They put the return in where one of the supplies used to reside. Then, they cut in a new supply. I'll mention that the new supply was the absolute last thing they did while trying to finish up. See clickable thumbnails below:
notice the supply is on the far right, in the corner. I thought the supply was going on the middle of the side, about 6 feet from the corner. For the record, the two doors you see are the walk in closet and the bathroom. There is one supply in each location.
for comparison, here's on the existing supplies that's on the opposite wall, almost centered.
As you can see, the new supply is pretty close to the return, and the diffuser is directing half the air right into the wall. Do you think it would help to get a diffuser that would direct all air away from the corner, or should I push to get that supply moved? That wall is about 12 feet long. I know the right answer is that it should be in the middle, but that would require drywall patching.
Any other thoughts or opinions? Thanks.
i personally think that cutting a round hole in the side of the furnace and stiicking a flex in it is crappy work .i like to cut the complete side of the blower compartment and add a sheet metal box or sit the furnace on abase can.
Does that return flex attach to the back of the furnace? not allowed by any manufacturer i know of, if it is attached to the back.
Duct/trunk lines from the back of case coil?
Good to know, Originally, they were supposed to mastic seal the return and then insulate it. They called me to ask if the could just replace that one section with flex. The goal was to quiet it down. There is a 16 inch collar mastic sealed in there.
Originally Posted by catmanacman
It attaches to the side. I wonder what the local inspector will think about all of these things. I'm having the company come back out to correct a few things anyway.
Originally Posted by beenthere
AFIK, silicone is against code in all 50 states, as it does not meet the flame spread requirements of ductwork...
should be aligned better, and it should be either mastic taped, or mastic sealed.
no air should be leaking anyplace on the equipment.
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