Just had a York 4 ton system installed and it seems undersized

[rossmosh]

Yesterday, I had a replacement AC and furnace installed. Around 5:30PM yesterday we turned on the system for the first time. The house was around 89* with a high humidity. It took until after 1AM for the house to finally get to 77*. The target is 78*.

Isn't that a real real real long time considering we are talking about night time with the sun setting? The air is coming out cold, but the flow seems off.

I know there are a lot of variables to answer this question. But it's a fairly typical NJ 2-story house built in 1985. Roughly 2800sq ft to cool. I know our insulation/ducting isn't perfect, but it's mostly satisfactory. The system installed is a TG9S120D20MP11A gas furance with a YCJF48S41S1A 4-ton AC.

[amd]

What size was the previous system?

4 ton system too small for 2800 sq ft? Unlikely.

Not propely comissioned/installed? Maybe. A system can't run at rated capacity/efficiency if it's improperly installed or charged.


The air is coming out cold, but the flow seems off

What does that mean?

Insufficient? Weak?


Around 5:30PM yesterday we turned on the system for the first time. The house was around 89* with a high humidity. It took until after 1AM for the house to finally get to 77*. The target is 78*.

Not necessarily abnormal. (especially if the windows were in direct sunlight in the evening)

[rossmosh]

As for the install: The company has been around for 60 years so I'm hoping they charged and installed correctly. Honestly, I went down around the blower and I feel quite a draft. I used the flame test and I know I have some leaks. A couple big enough to make the flame go out.

The flow feels a bit weak. I'm timing how long it takes the AC to run when it needs to maintain the current temp and right now it turned on around 9:50AM and it just shut off at 10:07AM. 17 minutes for roughly .5-1 degree drop. It seems to turn on every 8 minutes to run for 15-20 minutes (from what I've measured this morning).

The house doesn't get a ton of direct sun light after 6PM. The sun set around 8PM yesterday. It was hot and humid out yesterday. High of around 90 and a low of around 74* with humidity near 60%.

[ampulman]

"Yesterday, I had a replacement AC and furnace installed. Around 5:30PM yesterday we turned on the system for the first time."

Your house was sucking up heat and humidity all day long. It's not just the 'air' that's being cooled; it's everything within the walls, including the walls.

Amp

[amd]

The flow feels a bit weak. I'm timing how long it takes the AC to run when it needs to maintain the current temp and right now it turned on around 9:50AM and it just shut off at 10:07AM.

Call the installer back to verify the blower speed and seal the ductwork. (Connection between the air handler and supply air duct)

[rossmosh]

I've already called the installer. I know the system is leaking. I'm not happy about that. I just wanted to get a second opinion so if the installer claims it is performing properly, I can make sure they aren't giving me a song and a dance.

As it gets warmer outside, the A/C is running more and longer. This is expected, but I'm a bit concerned about the run times. They seem longer than what I'd expect from a brand new system. I'd expect a 5-15 minute run to get the house down to temp. This seems to be running around 30-45 minutes to keep the house at 78*.

[mchild]

As for the install: The company has been around for 60 years so I'm hoping they charged and installed correctly.

Honestly, I went down around the blower and I feel quite a draft. I used the flame test and I know I have some leaks. A couple big enough to make the flame go out.



Please re-read your own words. You hope they installed correctly but you have significant air leaks of the ducting near the indoor unit. Rather obvious that if they won't/couldn't seal those air leaks that there are likely other short cuts they have taken.

You may want to have the static pressured checked to make sure you are moving the air that the system requires and then also check the super heat and sub-cooling to make sure the refrigerant charge is correct.

[rossmosh]

Please re-read your own words. You hope they installed correctly but you have significant air leaks of the ducting near the indoor unit. Rather obvious that if they won't/couldn't seal those air leaks that there are likely other short cuts they have taken.

You may want to have the static pressured checked to make sure you are moving the air that the system requires and then also check the super heat and sub-cooling to make sure the refrigerant charge is correct.

I know......I'm trying not to think they did a bad install because if they did I'll end up driving over there and throwing a brick through their window.

What numbers should I be looking for on these tests? I'll ask them to do the tests, but I have no idea if the numbers are good or bad.

[mchild]

I know......I'm trying not to think they did a bad install because if they did I'll end up driving over there and throwing a brick through their window.

What numbers should I be looking for on these tests? I'll ask them to do the tests, but I have no idea if the numbers are good or bad.

It should be in the installation manuals. For SH and SC it should be on the cover of the outdoor unit.

Static pressure - in simple terms, is the measure of resistance to the air flow. In the install manual is a chart that shows the air flow of the system at different static levels. If the static is excessive high (greater than .70 or so) then the air will be reduced and your cost of running the blower will be higher than it should be. Also, high static with a variable speed blower can cause premature failure of the motor. They have to know how to take the readings otherwise the data is meaningless.

Did they do any duct work/modifications?

[amd]

As it gets warmer outside, the A/C is running more and longer. This is expected, but I'm a bit concerned about the run times. They seem longer than what I'd expect from a brand new system. I'd expect a 5-15 minute run to get the house down to temp. This seems to be running around 30-45 minutes to keep the house at 78*.

Outdoor temp?

How did the old system perform and what size was it?

[jerryd_2008]

Installed a 17-18 SEER, 4 ton, 2 stage, VS, York DFHP last year replacing a 4 ton single stage 10 SEER AC/furnace. Both handle a house around 3700 sqft. It is 97 out there now and the unit has absolutely no problem keeping up, the vast majority of the time in stage 1.

The drafts sound like a problem but probably not a serious problem. Unless they really screwed up the duct work or matching up to the existing they should be able to easily fix. No duct tape! Mastic or tape specifically designed for HVAC.

[smittyii]

the first thing i would be interested in is the temp drop acroos the coils. especially after it has run for 5 or 10 minutes. take a reading at your return air and at the supply closest to the blower. it should be 12 to 18 degrees drop across the coil. if you have that and its charged to subcooling method , then your problem is external. maybe too much heat load, not enough cfm, the air leak etc... good luck.

[rossmosh]

I have to take a step back from the situation because otherwise I'm going to do something rash. They came back today and here is my summary of what went on.

1) They did not, and do not, test for leaks other than putting their hand up to "feel" if there is a leak. The idea of using a flame or smoke is completely foreign to them. On top of that, I was told to "expect some leaks. You have leaks everywhere in your house". I told them flat out I don't care what the rest of my house is like, you just installed new duct work and it shouldn't leak. I had to sit there with a lighter and show them where leaks are. They only used caulk and a few select pieces of tape. Most of the leaks are sealed up but I went down to check on how the caulk dried and there are still a few strong enough to blow out the flame. We also had an old humidifier which we said we wanted installed if it worked. Now the humidifier leaks like crazy. I'm going to have to address that issue as well.

2) We reused our thermostat based on their suggestion. When doing the install, they obviously needed to remove the cover. While doing so, the thermostat got loose from the wall. When they were here, I told them to put it on the wall. They said they would do so, but "we won't be responsible if one of the pins break. We can supply and install a new $400 thermostat for you though". I took a screw from my garage and secured it to the wall. Took 3 minutes.

3) I told them I wanted the drain done to code. I was told specifically by 2 contractors that we could no longer drain into our french drain and needed to go directly into the sump pump. Their answer was "We'll do it if the inspector requests it".

Frankly, if it weren't a case of permits and dealing with the cooling fluid, I would have just done the install myself. Not taking anyway from true professionals, but these guys I've dealt with are not professionals. Stupid things like dropping a bolt for my AC panel and then not replacing it truly shows that. What happened when the AC turns on? The panel rattles. You'd think they could figure that out with 15 years experience.

Now I have to decide if I'm going to bother dealing with these jokers still or get another contractor in. The idea that they aren't interested in actually sealing up the ducts and putting a $.10 screw in the wall has put me over the edge. I'm hoping this is a case of 95% correct and those final "details" being ignored.

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Question: I went to HD and got 3 different types of foil tape. I didn't see any mastic tape. I might have just missed it or it might have been in a different aisle. All Nashua brand: 322, 324A, and 330. Any of these acceptable to use on the blower ducting to get a perfect seal? Otherwise I'll just keep caulking until it's right. I just thought caulk and tape would be the best answer.