My husband and I live in the southern Chicago suburbs. Humidity does get quite high in the Chicagoland area. I am extremely sensitive to humidity and would like to keep it as close to 30% as possible.

To save gas/electric costs, on April 24, 2008, we replaced a functioning Carrier system (I'm SO sorry that we did) with an 80% efficiency American Standard Freedom 100,000 BTW 80%, 2 stage variable speed furnace with matching coil. We also installed an American Standard Allegiance R-410A 3 1/2 ton 14 SEER air conditioner. We also installed an Air Bear media filter system. They also installed a new Honeywell Programmable thermostat.

From day one, I felt that the humidity was too high in the house. I have bad allergies and often keep the house closed up just to keep the humidity low and the allergens out. The Owner/Installer told me to hang in there because an AC will not efficiently remove humidity unless it can run for a good long while. That made sense to me so I waited until it got hotter here in Chicago. The humidity levels were bearable while the heat was still running although I did turn off our humidifier because I didn't want to add any more humidity to the heating system.

I've had the house closed up for about a week and a half straight now. I bought a hygrometer and the humidity inside will not go below 55-60% with the thermostat set at 71 or 72 degrees which is my normal setting. I didn't do the salt test on the hygromter but I did put it outside for about 6 hours and monitored the humidity reading against a close local weather station. So I feel I know the differential readings on my hygrometer.

The company came back out last Thursday, checked freon and all installation items and says everything is fine. They even talked to American Standard and got some suggestions. I called the owner of the company that installed the system on Friday to tell him that what they had done had not helped. On Saturday morning, he told us to turn the thermostat to 65 degrees and let it run to get the humidity down. We did that and the humidity lowered from about 60% to 45% over the course of about 8 hours. The system ran without stopping the entire time. The temperature never went below 71 degrees even though it was only 83 degrees out yesterday. Once it got about 7:00 p.m., it finally went down to 69 degrees. As soon as we turned the thermostat back up to 70 degrees, within an hour, the humidity level in the house went back up to about 53%.

On the day before, I noticed that the air, set at 72 degrees on an 80 degree day would come on for 10 minutes and be off for only 10 minutes. Is this normal or is this what is called short cycling? If so....what does that mean?

I am horribly uncomfortable. The installer acts as if this is an ok humidity level. As I said before, we had an old Carrier AC unit from around 1991 that was able to cool properly and keep the humidity at or below the 30% level. Nothing else changed in the house. This installer has been doing our maintenance on the old system for about 8 years so he knows that we never had an AC issues. He's coming back out on Monday but says he's stumped and has never seen this problem in 37 years. Do we have a lemon AC?

We bought the American Standard extended full system warranty for 5 years. Can we hope for any help from them? Should we call another AC installer to look at it?

Help.....my husband and I are not mechanically inclined at all nor do we have anyone else who can help us.

cassieandcameo

Hey Irish! AirEase is the company who installed the unit. They were VERY responsive. After contacting American Standard, they were guided through the adjustments to make in the "dip switches"? Anyhow, the problem has been fixed and the unit is now removing humidity.

If you know Dornbros you must be Southside. AirEase is in Tinley Park. They were very good to us. Never made me feel crazy.

Good Luck.

hvac1000

The cure is to lower your indoor blower speed and let the air get more hang time at the coil. This will cause more drop out in the humidity department and you will be more comfortable.

Another note: If your unit was sized to large or to small this could also be a problem

KarenfromOhio

Interesting . . . we contacted American Standard and were given the name of another AC person in the area. That person told us that the newer units do not eliminate the humidity as well as the old ones. We were told that humidity hovering around 50% is acceptable. The guy told my husband that AC people should not be selling the units without being upfront with customers about how the newer units run differently.

So, we're been living with 48-52% humidity and feel like that is what we have to accept. The guy did come out and adjust the blower speed, but I'm not seeing a real difference. Our humidifier is off.

I still don't believe that we are supposed to just "accept this."

cassieandcameo

Mine is lower, Karen. It's more in the 33-42% range but then every humidistat is different too. All I know is that it feels comfortable to me now. When my humidistat goes below 40%, it shows a sad face but MY face is happy! I wouldn't be happy at 50% either.

My guy did not just lower the blower, he also changed some switch settings.

KarenfromOhio

Cassieandcameo: Any idea what he switched? I don't think our person really knew what he was doing. Many thanks--it is encouraging that the problem can be fixed. We keep our temperature at 70 degrees. I had thought with the new unit we should be able to set it at 72 and be comfortable---but that is not the case. What temp are you running yours at?

KeepItSimpleStupid

I looked at a good readable copy of a comfort chart. It generally states that most people are comforable between 70 and 75 degrees and and Relative Humidity between 30 and 50%. I had a chart with a summer/winter component somewhere.

hvac1000

Don't operate the air conditioning with any windows open. This includes opening bathroom windows when taking a shower or to reduce odors. Yes, this brings in fresh air, but humidity in the air will condense onto the registers that are nearest to the open window. If you must open a window because the bathroom doesn't have an exhaust fan, close it as soon as visible moisture on the walls and mirrors is gone.
Don't run the indoor blower on continuous operation. If you do, any water left on the coil or in the drain pan will re-evaporate when the compressor shuts off. This can raise the relative humidity in the house by 15%.
Don't set the thermostat too low. If you have the temperature in the house too low, you increase the risk of condensation forming on some surface in the house. This could even occur on a hidden surface, such as inside the walls.
When operating exhaust fans, remember that while you're exhausting air and moisture to the outside, you're also bringing air and moisture back in from the outside. Whatever you blow outside will leak back in somewhere else. Don't run your exhaust fans any longer than necessary. This includes bathroom exhaust fans, kitchen exhaust fans, range fans, and clothes dryers. If the air outside has more moisture in it than the air you're exhausting to the outside, you're doing your house more harm than good.
Make sure exhaust fans terminate outside. I've often seen dryer ducts that terminate in the crawlspaces and attics. Many bathroom exhaust fans blow into attics. This can cause tremendous moisture problems in attics and crawlspaces. Your air conditioner cannot handle this kind of problem.
Don't pile ground too high against the house. Water can wick into slab edge, foundation, and crawlspace. Waterproof the edges of the slab or the below-grade foundation walls. Put moisture barriers on top of all foundation piers. Don't let wood contact ground or bare concrete.
Consider installing a dehumidifier in problem areas of your house, basement or crawlspace. Keep in mind that there are whole-house dehumidifiers that can be connected to your air conditioning and heating duct system that will dehumidify your house extremely effectively, thus improving both your air conditioner's performance and your comfort.
Home infiltration from natural building leakage. This includes crack leakage around doors and windows as well as electrical outlets and other building envelope cracks. Plumbing pipes coming up through the floor from a crawlspace can also leak air into the house. This infiltration is mostly wind­ driven. Leaving windows open during cool mornings in the summer has the same effect. Even though the outside air temperature is low, the moisture levels in the outside air can be very high. If the house has a damp crawlspace or basement, water vapor can penetrate through wood floors into the house. Water vapor flows from high concentra­tions to low concentrations, just like heat. This is in addition to air infiltra­tion already described above.
Improperly sized and improp­erly installed air-conditioning sys­tems. Significantly oversized air condi­tioners and heat pumps do not control humidity as well as properly sized units. This is because the indoor coils do not get really cold until after the cooling unit has been running for as long as 15 minutes or more. Oversized units tend to short-cycle: they cool the air quickly, and then shut off.


About R-410

Home - R-410A - Honeywell AZ-20 Refrigerant

If a slower blower speed does not help with humidity removal there is something wrong with your system. Call someone else who is more experienced with R-410 and get it fixed. Back bill the original company for the work. If they do not pay take them to small claims court.

NOTE keep all documentation and have it clearly stated what was causing the humidity problem and what was done for the cure.

BEEN there done that for people as a PW (professional witness)

KarenfromOhio

Cassieandcameo or anyone else: specifically, what switches need to be adjusted? We are willing to call your person/company in Chicago for help. As for the suggestions, we are pretty good with the common sense pieces. However, I did not think that we should also have to install a dehumidifier to use concurrently with the AC. We did not need it with our old clunker that we had . . .

Missouri Bound

I replaced my Honeywell thermostat (mercury type) with a programmable White Rogers thermostat last heating season. I kept it at a constant temperature because when ever I set it back, it needed the aux heat to recover, and that didn't help my electric bill. Now this summer, when I switched to cool, I found that I had a problem similar to yours, unit turns off and on too quickly (in my opinion) and the humidity is always around 50-55
%

So I decided to put my old Honeywell thermostat back on and instantly noticed longer run times, but fewer run times. And now the humidity stays around 36%. At 75 degrees I find this comfortable. If the unit is working as it should, try an inexpensive mercury type thermostat. You lose the programability, but you may get the comfort level you want. At any rate, it worked for me.

KeepItSimpleStupid

There are programmable stats. At least one of the Vision Pro 8000 models (e.g. 8321) has the capability to "dehumidify". What it will do is lower the room temperature up to 3 degrees to attempt to attain the RH setpoint.

In a mechanical stat, the "anticipator" creates the deadband. If the deadband is higher, you get increased cooling and lower humidity. So, there is basis that the machanical stat will work.