[yuri]

He is correct. ACs need to run fairly long to remove humidity.

The issue is we have gone overboard with the amount of programming and "setback" features and dehumidifying and zoning and it can confuse the system.

It works OK in large commercial bldgs and office towers etc with full blown BAS bldg automation systems but a house is too small to get into that fine detail.

However Carrier has that technology as they are one of the top tier brands for R@D and put it into resi units. Zoning makes it even more confusing in a house. W/O zones it works pretty well.

 

[yuri]

I understand your frustration and will try help you with what I know of a full blown Lennox Harmony 3 zoning system I installed.

Lennox highly recommends a 2 stage AC with it. Reason being it needs to run at 2/3 capacity when only the largest zone is open and some smaller ones close. Otherwise the cooling coil can freeze up and liquid refrigerant slugs back to the compressor and damages it.

There is a discharge air sensor and it prevents the furnace from overheating when zones close as well as monitors the AC supply temp. If it is too cool it may stop the outdoor unit.

I would suggest you try run it without the de-humidfying part as a test to see if at least the regular AC works. If it does then IMO the de-humidfying is confusing the whole works.

I worked with very complex BAS building automation systems in a Convention Centre and hospital and can imagine all the permutations and combinations the system is trying to do. IMO that is too complex with a small system.

 

[yuri]

Your cycles are getting better.

You need 5 mins off to let the freon pressures equalize. Ideally I would want it to run 20 mins to remove more moisture and then be off 7-10 mins. Excess starting and stopping is pretty hard on the compressor. Just like turning your car motor on/off.

I know this is frustrating as you paid LOTS of good $$ and want it to work. Myself and Beenthere have about 70+ years of experience plus a few more techs here have quite a bit.

I had a complex wacked Carrier zoning problem we helped a guy with here a year ago. Had to do with poor sized ducts and contractors who do not totally understand duct sizing. Frustrating as heck as you pay lots and expect it to work.

However lots of guys can install these units but not so many can make them work well. Totally different when you get BAS Building automation as we get Siemens or Johnson Controls in to do a lot of it but that is another story.

If it was my system I would not try have drastic setbacks as IMO more even cycles are better.

I don`t see that much Carrier high end stuff as when I sold them as now I do mostly Lennox. Not sure if you can disable the dehumidifying or alter it.

 

[yuri]

The guy with the Carrier zoning problem ( undersized return etc ) had to call the district representative for Carrier and convince him there was a problem and that the contractor was brushing him off.

I suspect you will have to do the same. The problem is Carrier and Lennox and Trane have incredible technologies ( resi units are like a childs play compared to the Commercial and Industrial equipment they sell ) but they take some of that technology and stuff it into resi units. IMO that is very difficult to do as you don't have the massive airflows and unloading capacity that the Commercial/Industrial units have.

That and they use mechanical engineers to properly size and balance the ductwork and the ducts are tested professionally. With resi it is slap it in and hope it works. Also the contractors don't all have techs who went to Carrier school to learn zoning etc as that costs a lot of $$.

Lennox is very good at providing us training classes, not sure about Carrier and others. The district manager should be able to get some results and lean on the contractor if you tell him you are going to "share" your experiences on the internet. Get my drift?

They hate bad publicity and especially when you bought their top notch modulating furnace and zoning system. They even have web crawlers reading these forums. Lennox does.

 

[yuri]

Not too likely it is going to work properly with a 1 stage AC. There won't be enough air going across the coil when 2 zones close to keep it from freezing. The fan will ramp up like a rocket but that won't solve the problem as it can only go so far. Then it can blow water off the coil.

I would talk to Carrier and see if they think it can work properly with a 1 stage AC. I hate to say it but if it does not work properly you can damage the compressor or have a off warranty failure later on.

Document all your times and readings in case there is a problem. W/O a paper trail you "are up the creek".