Thread: Need advice on New Ac and heating unit

Hello, I had a new AC unit and Heating unit installed in my house a year ago. We live in NJ. We have approx 1,000 square feet downstairs and approx 1100 square feet upstairs. The upstairs has 3 bedrooms total and a bathroom. Two of the bedrooms have highceilings (with no attic above them) nor does the bathroom. And the third bedroom has a small attic above it. The upstairs was extremely hot and takes a beating from the sun given the fact that there is no insulation above the two rooms. The downstairs has regular 8 ft ceilings and is always generally cooler than the upstairs. The heating system heats the entire house. We have a 2 separate condensers for the ac. One unit does the upstairs which is a 3 ton unit we had installed in 2002. It works great. Takes the humidity out, we generally keep the upstairs set at 78-79 degrees and it always feels cool and comfortable. Our previous downstairs ac unit was always comfortable until it died. We were advised to get a new ac unit, so we had the heating system replaced as well. They installed a lennox G61-mpv-60-c-111 110,000 btu AFUE 95% heating system. And a Lennox XC14-036 33,800 btu ac system 3 ton coil cr33-48 with a seer of 15/12.5. So now to the problem. The AC unit cools the house to temp quickly but leaves the downstairs completely filled with humidity even after running for 2 days. The owner of the hvac company said my system is complicated. Told them never had problem before and said my old system probably wasn't working properly and thats why not a problem before. I contacted lennox and they said the unit could be oversized. Do I really need a 3 ton unit to cool my downstairs? He keeps telling me yeah but you also have to heat the whole house. But I also have a 3 ton unit properly cooling my upstairs. The ac unit short cycles about every 7 minutes to the t to keep to temp. It was cycling every 6 minutes but then they adjusted the blower speed from high to now low and said thats the problem. But the house still feels humid yet cool..Clammy is a good way to explain it. What should I do. I asked the owner if the unit was oversized based upon what lennox said and he became belligerent. I also had 2 companies come out and tell me the ac unit was oversized. Is it impossible to heat a approx 2000 sq ft home through one unit thats appropriately sized without oversizing the ac unit since its only cooling my downstairs? Is this really that complicated? thanks.

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Here is what the NC Mechanical Licensing Board says about what you are experiencing. It may help you with your argument. I would ask the contractor for his load calculation sheet. I bet he does not have one. And there is no way to properly size a unit without one!

http://nclicensing.org/_fpclass/_nos...Newsletter.pdf

thank-you for your quick response. He never measured anything. I don't even know about what he removed to be quite honest. Not a great customer experience from my standpoint. I am in medical field sales and my Dr's would never have this. Thank-you again.

I just looked at the requirements to be a heating contractor in NJ. It looks like there are none except for registering as a home improvement contractor.

Here is how to file a complaint....

New Jersey Division of Consumer Affairs - Home Improvement Contractors

It is super cooling the home. It is cooling before it can remove the humidity in the home. This is a very good indication of an oversized system.

You have a total of 6 tons of AC cooling for a 2100sf home. 6 tons of cooling power is enough to cool a 3,000 to 3,500 sf home. Rule of thumb would tell any HVAC contractor that a 1.5 to 2.0 ton unit would be about all that would be required to cool the downstairs. I would also say that 110,000 btu is enough heat to take care of 2,000sf home in most parts of the country. I would be happy with a unit in the 75,000 btu range for heat.

If you do not get this corrected you will have a mold farm in your home, if you do not have it already.

Hello again, So the hvac contractor came back out again today and said we need to let the system run for three days to get humidity out. We turned the system on too late again. So the system is currently to temp when he left with system at 76 degrees with 56% relative humidity and he said this is a fine range to have. Still feels that the unit is properly sized for my house. He is taking everything back for a j load calculation but said the j load calc will not work because I have one heating system and 2 separate cooling systems (ac in attic) and ac for downstairs. Keeps saying my system is so complicated. What is so complicated I do not get it. I am in the medical field, cancer is complicated, how complicated can this be? Could you please advise to the humidity level and how quickly the humidity level should drop once the unit is turned on? Are there charts or anything I can reference?Because it always hits temp inside. I understand that the rh inside will vary depending on outside but there must be something you guys go by?? thanks for your assistance.

In my opinion a properly designed A/C system should run constantly at the outside design temperature which is 95 degrees in NJ. To accomplish this you need to know how much heat gain you get in the house at 95 degrees outside to see what the maximum system size should be.

Originally Posted by mickalene calavano

Hello again, So the hvac contractor came back out again today and said we need to let the system run for three days to get humidity out. We turned the system on too late again. So the system is currently to temp when he left with system at 76 degrees with 56% relative humidity and he said this is a fine range to have. Still feels that the unit is properly sized for my house. He is taking everything back for a j load calculation but said the j load calc will not work because I have one heating system and 2 separate cooling systems (ac in attic) and ac for downstairs. Keeps saying my system is so complicated. What is so complicated I do not get it. I am in the medical field, cancer is complicated, how complicated can this be? Could you please advise to the humidity level and how quickly the humidity level should drop once the unit is turned on? Are there charts or anything I can reference?Because it always hits temp inside. I understand that the rh inside will vary depending on outside but there must be something you guys go by?? thanks for your assistance.

Have you ever palyed the game"You don't know Jack" it is a pretty fun game. You may know cancer but I bet you would get slammed half the time playing that game because you know cancer but you don't know Jack (not an insulat at all. I suck at the game). The game of homes and the game of cancer is the same thing. They both are involved in complete system which means everything in the home ... everything. All of it has an affect on the final outcome of how well a system works. Air up stairs. Heat and air down stairs. Each system drawing air from the other system which is all in the same envelope.

I have know idea if this HVAC contractor knows what he is doing but he may very well. He probaly wishes he could tear it all out and put in a couple systems, complete systems, or one system with a couple of zones instead of working with the piece meal system that is in place.

You know cancer so this guy must be an absolute idiot for not figuring it all out quicker. Wrong comment. Never pit yopurself against other professions with the mine is bigger than yours thing. Not cool.

One of those idiots that has a do nothing career, James Duffin, has been in that do nothing uncomplicated world for years. He must love being referred to as a putz do nothing uncomplicated world type of guy and an underling to you because ..... you are involved with cancer and how complicated could it be , huh.

Wow......you are one crazy dude! You like to make things way to complicated and this is another example of that. The OP is asking for generlizations....not a course in stupidity like you just gave him!

Ok, not sure what to make of your response, but, ok. I realize things on email or in chat room are difficult to treat. I didn't, mean my post as anything negative, didn't mean for it to come across with that demeanor! Just looking for help. Interesting all together.

Oh my! Crazier from my standpoint to be quite honest! I just need some help. I am just a consumer of a HVAC system and just looking for some good troubleshooting. As my HVAC contractor does not seem to be doing. I think given my background, I think, I am a smart, educated, individual. Clearly in the HVAC area I am not, but, that is why I am turning to you guys to help me out and help educate me! I am capable of learning great things. I think, depending upon, what you guys give me! Thanks!

Oh, and be gentle if you may. I am a girl! Just a smart one in the medical field anyway. Please help, I am a good listener and data collector. Thats what I do for a living! I am here to learn!

Originally Posted by mickalene calavano

Oh my! Crazier from my standpoint to be quite honest! I just need some help. I am just a consumer of a HVAC system and just looking for some good troubleshooting. As my HVAC contractor does not seem to be doing. I think given my background, I think, I am a smart, educated, individual. Clearly in the HVAC area I am not, but, that is why I am turning to you guys to help me out and help educate me! I am capable of learning great things. I think, depending upon, what you guys give me! Thanks!

Great. Systems are complicated as far as explaining them online. Charts and load calcs might be passed around and maybe even a direct anse=wer can be given that would be the fix.

As James said I guess I gave a lesson in stupidity. Not sure what that is about considering. This is your quote

"I am in the medical field, cancer is complicated, how complicated can this be?"

It can and does get complicated at times trying to balance it all out. What you may need to do is get another HVAC man out there. He will measure everything. The size of the home, the volume of the home, the amount of openings in the envelope etc etc etc. You have 2 cooling systems and one heating system. It does not sound all that complicated but everything must be sized ... for your home.

I hope everything works out. I do know how frustrating this can be.

Some simple thoughts...
Have your home and the new system evaluated by another HVAC company. Be up front with them and tell them what your issues are and what you had prior. Ask them to do the proper analysis and tell them you will want a written copy of their estimate and report. You may have to pay for this service since they will realize that they are very unlikely to get any business from the efforts. A few hundred dollars of diagnostic work will be worth the effort if your contractor has improperly sized the system. Also ask them what can be done with the existing system to modify it so it works better in all seasons
On the surface from what you have written as well as the responses it is likely that the system is not sized correctly, however there are too many variables and there is no way for you to provide all of the needed information to receive a short and simple answer in this forum.
In the short term run the upstairs unit set 2 degrees cooler than your normal operating temperature of the first floor unit and it will likely remove a significant about of the home interior humidity.