We have central air conditioner, do we need dehumidifier.?

It depends on the climate and your house.

If the weather is muggy but not particularly hot, a dehumidifier can keep a house comfortable without running the central air conditioner. Also, some houses may become damp even with a central unit running, particularly in basement rooms. A dehumidifier will prevent mold and other problems in those areas.

But if the weather is hot and dry, a dehumidifier is probably not necessary.

Central Air Dehumidifier

Sure, you can put in a window air conditioner, even if you have central air. You need an outlet and breaker that will take the load safely without tripping. The idea of a dehumidifier is a good one, if your central A/C is not dehumidifying well. Some things i tell people who complain about poor cooling A/C: 1) Close windows and blinds. Make you house a cave, light equals heat 2) Turn off unnecessary lights and Appliances. Run washer and dryer in cooler times of the day 3) Have the A/c system checked and serviced by a professional at start of the A/C season. 4) Change filter on furnace every 3 months or when dirty. This is the same filter for A/C and heat 5) Make sure your room vent is wide open and not blocked by furniture, drapes or carpet

I have lived much of my life on the Gulf Coast of Louisiana and Texas. No one uses a dehumidifier in conjunction with their air conditioner. Doing so just doesn't improve the comfort in your home.

You would only use a dehumidifier if you had to have a very, very low humidity for health or other reasons.

Do I Need A Dehumidifier

If your AC is significantly oversized, then it will "short cycle", meaning it will turn on, quickly chill the air, then turn off, leaving high humidity, meaning you need to either resize the AC or add a dehumidifier. If it's properly sized, it will dehumidify properly. According to industry experts, a properly sized AC will fail to cool to 75F three percent of the year -- about a week and a half, in the hottest weather. Most Homebuilder oversize about 10%, which costs a bit more to install and a bit more to operate, but in return will cool to around 73F except in very unusual conditions. AC contractors like to oversize 20%, so they make more money, have fewer callbacks, keep their builders happy because THEY don't get callbacks. I oversize 10% above manual J, and have happy customers.

Air conditioners are the least efficient dehumidifiers! While they do remove moisture, if you are in a humid climate, a dehumidifier in conjunction with your A/C would be best and reduce running costs and times of your A/C thus reducing electric costs

I live in South Carolina - this summer has been very humid and I think more rain than usual. When I walk in my house it smells of mold or wet old dog like smell. I have a master's in cleaning (LOL) so it's not that.....I am thinking I need a de-humidifier...yes? oh! Our house has a crawl space but everything seems dry underneath..........any suggestions/help? Thank you in advance :-)

No, you do not need them,