What temperature are you setting on the thermostat? How are measuring the indoor humidity and how accurate is your measuring device?

The AC can only lower the humidity when it is running. If the temperature is set at 76 the AC will have less run time then it were set at 74. A humidity level of 60-65% at 75 degrees should be fine. If you want lower humidity you can will need a dehumidifier. In your location it makes sense to buy a better machine and not the low cost type sold at the big box stores.

Relative humidity levels of 60% or more are typically required to support growth of mold and mildew. And the relative humidity needs to be at or above that level for a sufficiently long time for mold spores to germinate and become established. Once established, however, mold and mildew can grow at relative humidity levels as low as 50% I suggest 50% R.H. as a target maximum indoor relative humidity, but you can find recommended maximum relative humidity levels as high as 60% The lower the target the higher the margin of safety.

A properly-sized air conditioner will remove moisture as it cools the air in your home and reduce relative humidity. In so called "shoulder seasons," where neither air conditioning nor heating is required, relative humidity control generally requires a dehumidifier.

With respect to operating bath fans, range hoods, etc. to deal with point sources of moisture, keep in mind that the volume of air exhausted needs to be replaced with an equivalent volume of outside (unconditioned) air. That can raise the indoor relative humidity.

We had no issues with indoor humidity during the hottest months of the season (RH inside maintained at 45%) but now as we are “in between” seasons in Florida - where outdoor temps are 60-80 degrees, our indoor humidity can be 60-65%.

This is a common problem for areas in which there is higher humidity. Humidity is independant of temperature. So this isn't anything unusual for a high humid type climate.

You can run your AC at a lower setting when it's not as hot. Most run of the mill AC's are not recommended to run below 55F outside temp as damage will likely result with out the addition of controls to operate as such. The trade off is that you will need to adjust to a cooler inside temperature than what you are accustomed to during the summer months. As the machines run based on temperature not humidity. Some HVAC systems that have humidity set points are limited in a tight band off the temperature setting. So you still have to adjust temperature setpoints for such systems.

Short cycling: when it's cooler out the AC system (most of them) are designed to lower temp. They are either on or off. So due to this there is little dehumidification from them unless you force them to run by dropping indoor temps further to force that additional run time.

2 speed AC's: you get some better dehumidification with these... but 1st speed is typically 70% of total capacity of the machine so in off season use they are still over-sized in terms of trying to dehumidify the home.

Enter the Inverter AC or variable speed AC; The ability to run in 1% increments up and down some systems could have upwards of 50 different speed levels or more. These machines still run off temperature, some may have dehumidify functions built into them -- but as mentioned above dehumidify functions are often tied to a temperature band off temperature set points.

The advantage to inverter AC is better dehumidification due to the nature of how it runs. Also it will pay for itself over time because you're only ever using the amount of cooling you need in 1% increments up and down. (some manufacturer's units may not perform as mentioned here due to configuration, design, etc)

Add a dehumidifier; sure this is one option but costs will go up. The cost to operate it, the cost to maintain it, the cost to repair it and eventually replace it... it's another system to maintain. Running a dehumidifier alone blows warm dehumidified air. Some people who are more heat sensitive than others won't like this mode of operation in that you're burning energy to dehumidify then need to burn more to run AC to drop the temperature. Some areas of the country a stand alone dehumidifier is the better choice but it's a very small market in my opinion. If you like it warmer inside with less humidity then this choice might be the better one.

Me personally I like it a bit chilly. I ran my Bosch Inverter last night... seeing record temps here in Katy, Texas with highs in the 80's. Humidity is always a problem here short of a few weeks here and there.

"Humidity is independant (sic) of temperature."

The terms "humidity" and "relative humidity" are often used interchangeably, but they are not the same. Absolute humidity is the mass of moisture per unit volume of moist air and is independent of temperature. Relative humidity is a comparison--expressed as a percent-- of the amount of moisture in the air with the maximum amount (saturation) that it could hold at that temperature. It is temperature dependent.

When we're talking about indoor conditions--whether design or actual--we're referring to relative humidity which is temperature dependent. With respect to occupant comfort, 35% - 55% +/- 5% relative humidity is generally considered a comfortable range, albeit influenced by a number of other variables (e.g., temperature, air flow, clothing) as well.

Depending on the specifics of the OP's system, they can consider retrofitting it to extend run times or adding a dehumidifier or both. If the equipment is nearing the end of its useful life, replacing it with a system that offers more turndown would enhance control of relative humidity. I live in coastal Virginia which is a mixed-humid climate zone. I've found the addition of dehumidifiers to be an appropriate solution for controlling indoor relative humidity during shoulder seasons for most applications in our area. I have one on each level in my home.

Relative humidity, which is what is usually measured, is dependent on temperature. Providing the relative humidity amount without a temperature does provide the amount of moisture in the air. That is is why I often ask what is the temperature for a given relative humidity reading.

Right now on December 29 in central New Jersey the outdoor relative humidity is 94%. That sounds like an unbearable humid condition. But you also have to consider the outdoor temperature is 43 degrees which also happens to be the dew point.

Thank you all very much! @mike_home I even at the highest indoor RH of 65% the indoor temp is maybe 74 at most, but most of the time around 70 degrees (again temp outside is 65-75 degrees). I may totally be overreacting, but just trying to stay on top of preventative measures.

I wouldn't say your are over reacting. At 65% the humidity level can become a problem over a period of time. If you are concerned then look into getting a dehumidifier. Get one with a condensate pump so you don't have to empty the reservoir several times a day.

"Humidity is independant (sic) of temperature."

Well I mean if you want an engineering lesson yes, that is easier than where this thread is about to go... Humidity refers to moisture in the air, not how much because? It varies like the wind because? temperature, pressure and how much moisture that air contains at a given pressure and temperature. Often times at the home level and even outdoor level atmospheric pressures isn't even thought of.

Why can it rain at 35F just as much as it can rain 95F or higher? The amount of rain? The difference from a spit type rain to a down pour? This is what I meant by the comment above...

For illustration purposes:

From picture above: does this mean that heavy down pours of rain only occur at 80F? Really? More to it than that...

say what? Didn't you stay awake in science class?

Dew points change, volumes change! Temperatures change? Yeah, you need to become a weatherman now...

It isn't enough let's make this even more complex so fewer people can understand it...

Don't forget about atmospheric pressure.

Theme music: "Under Pressure" by ZZ Top. LOL.

Ray,

You can probably swap out an outdoor unit faster than you could read the instructions on one of your YouTube videos. Psychrometrics isn't your strong suit no matter how many visuals you include in one of your posts.

Sure Charles. Same old line beating down the guy that does this for a living in a high humid environment no less. From a builder who doesn't know the difference between a furnace and an Air handler / Fan coil.

I am not here to teach you or anyone else how to do it. They have trade schools for that. The same rhetoric gets the same response from me over and over... will you learn this time Mr. Ross?

The builder builds your home and often times is the end result why you have trouble with your home. This thread is Home Repair / HVAC --- not builder's festival 101.

The builder has a hard line on anything they build in terms of what they will honor or won't honor when it comes to humidity problems. Now why do you think?

Fill in the blank _____________________. I know the answer already. 27 years in HVAC... I am rarely surprised any more. Choose what ever you want... if you like builder grade info -- go for it. I know from experience (27 years worth) that won't last half as long as you think it will.