AC QUESTION- What should the humidity be?


I think I accidentally closed the discussion on my AC question.

I had purchased a moisture meter and sent the product description as asked.

Today I purchased a humidity meter. What should the humidity be inside the house if temperature is 76-77?

My neighborhood is having sewers cleaned and"I" have been ill. So trying to figure out if the odor from outside is making me feel ill, or if it is AC or duct.

Thank you!!!

  7 answers
  • Dfm Dfm on Jul 09, 2018

    you set it at a level that is comfortable for you. I’ve had a few sinus surgeries so I keep the moisture level a bit higher in the house. The sewage can certainly make you nauseated.

  • It all depends on where you live, the climate and your energy costs. Humidity should be between 50% - 60%.

    Office buildings are set at 72°.

    I live in a hot and extremely dry climate, over 100° with less than 10% humidity. My thermostat is set at 78 or higher. I would love to have it set at 75, but the cost is too high and my ac runs continously as it is. 72 would be heaven.

    My best guess is the outside odors are making you ill. Change or wash your hvac once a month for optimum efficiency. Call your doctor if the feeling persists.
  • Shore grandmom Shore grandmom on Jul 09, 2018

    I found your old post:


    • Hometalker

    Asked YesterdayIs it normal or abnormal to have a moisture reading at an AC return?

    Answer   +2


    I have been smelling moisture and and not feeling well. I think the problem might be coming from an AC return. I purchased a moisture reading. Is it normal or abnormal to have a moisture reading at an AC return? The reading was 7 on a moisture reading.

    Thank you!!!

    5 answers

    • Ken
    • Jul 08, 2018
    • Usually moisture in the air is measured as a percentage relative humidity. A reading of "7" is not from that kind of meter. I don't know what kind of meter you have.

    • Water should not be in your return duct but since it is returning to the air conditioner it should not affect you. It's what is coming through the supply duct toward you that should be of concern.
    • Like
    • Reply

    • Shore grandmom
    • Jul 08, 2018
    • If you're smelling something and not feeling well, you may have a mold problem. An AC return is just that, it takes to air out of the room so the AC can cool it and send it back in through the air vents. Nothing should come from the return. Don't wait to have this checked. Especially if you have children, elderly or someone that has a compromised immune system around.
    • Like
    • Reply

    • Barbara
    • Jul 08, 2018
    • I don't know about moisture reading either. So that's no good. Have you changed your filters? Call the HVAC company, because the pipes in the attic area may be leaking. Look outside at the outflow pipes on the wall. If water is coming from the top pipe, your AC will need to be seen to by a professional. Do it fast! You may be breathing in dangetous spores and bacteria
    • Good luck.
    • Like
    • Reply

    • Flipturn
    • Jul 09, 2018
    • Is the 'moisture reading' a device? Where did you buy it? Did it come with any pamphlet of instructions? Please post a picture of what you purchased, so that we can see what you have.
    • Like
    • Reply


    Jul 09, 2018

    the moisture reader is

    General Tools and Instruments Digital moisture meter from Lowes item # 78059 Model MMD4E. Has a 4.5 rating from 68 customers.

    Today I made some calls n someone told me to buy a relative humidity reader but I only found a humidity reader.

    My community is having sewage manholes (I think the manholes) cleaned and sanitized. So my issues might be coming from that. I called the company and they said I would not be effected in the house. I do not believe that.

    My issues seem to get worse when they are working outside my house "and" the AC turns on. I am not sure if it's the AC, the ducts or the outside work is effecting me. I was trying to figure out "what" is causing my issues.

    I started with the moisture reader that has prongs.

    Now I will try a humidity reader. I don't know if the inexpensive humidity reader would be as good as the expensive relative humidity meters. Anyone know?

    I need to figure out what path to take. I am hoping everything will subside after the work is completed outside my house but wanted to do some exploring also. No one else in my house or in my neighborhood is having issues but "I" have multiple chemical sensitivity issues.

    Thank you for input!!!



  • Joy30150932 Joy30150932 on Jul 10, 2018
    It may be wise to have the technician come to your home to check out the appliance, clean it and set your humidity control for you. If the humidity in your home is not right you could end up with all sorts of problems both health and home.
  • Sharon Sharon on Jul 10, 2018
    I've been made ill by ACs frequently cause I am allergic to mold. I would try to stay in one room and put an air cleaner in the room. I would even resort to wearing a good mask while the work is done. Plus have the AC serviced and cleaned.
  • William William on Jul 10, 2018
    AC system takes humidity out of the air. That is how the air is cooled. I am going to assume that the odors from the sewer work is enerting you house and being circulated by the AC.

  • Min33764446 Min33764446 on Jul 10, 2018

    thank you finding initial post Shore grandmom !!!

    Has anyone ordered a mold testing kit from amazon? If so can you tell me which one? I think that might be more cost effective than a home depot kit. I would do a home depot kit if preferred.

    I plan on hiring a professional but trying to figure out where to "start".

    I changed filter ... it was dirty.

    I tested for moisture and reading near AC was 7.

    Tested humidity but can't get it below 50% without going very low on the temperature which would make my central AC bill very high.

    AC duct estimate 3 week wait.

    Calling for AC tune up.

    With the sewer work going on in my neighborhood now I don't think it is wise to bring in a professional mold and professional air tester yet.

    Any suggestions for a good room filter while I figure this out? I have sensitivity issues to mold and dust so I need something that works. I was going to look through consumer reports but someone with multiple chemical sensitivity issues would have a better suggestion.

    I have a filtrete MERV 13 air filter. Could that be doing anything to the system because the MERV is too high? ... blocking airflow? I read somewhere that a high MERV could cause a problem. Sounded odd to me.

    I contacted the sewage sanitizing company and they said odor can't be coming in the house. I DISAGREE!!! When workers outside nose burns, feel nauseous and have brain freeze. I have to leave my house.

    It is better after they leave but I still feel the lingering in the air and it gets worse when AC turns on...that part I don't understand....getting worse when AC turns on.

    AS a side septic tanks in my area in case anyone was wondering. I have county hook up for sewer and water and I only drink bottled water. Which brand is another topic ;}

    THANKS for your input!!!

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