I do change the filter every 6 months. I wanted the higher humidity setting because my wife has 'dry eyes' and the eye doctor said higher humidity might ease the symptoms. It's not critical to get to the high setting, just something we thought we'd try. Okay...I get the a/c running will dry out the air, just like all the old systems do. So the setting on the thermostat is just to give the unit a maximum humidity limit? and turning it OFF doesn't really make a difference if the humidity is staying in the 40-50% range anyway? Appreciate your response!

You said:

"I've set the dehumidifier in the thermostat setting to the maximum 65%, yet the reading on the thermostat says 44-45%. I've also gone into the advanced settings and turned the dehumidifier to OFF, and the humidity reading went up to 51%"

And then you concluded:

". So the setting on the thermostat is just to give the unit a maximum humidity limit? and turning it OFF doesn't really make a difference if the humidity is staying in the 40-50% range anyway?"

Does this make any sense?

Sorry if my confusion doesn't make sense. Guess that's why it's called 'confusion?'

Overall, my initial concern involved the UV light, the humidity percentage, and the impact on the coil from higher humidity setting and no UV light. It might seem simple to those of you who understand a/c units, but I had to learn by asking.

Thanks to an earlier reply from Mike, and discussion with another knowledgeable a/c person, I think I can say my questions have been answered. The coil will not be negatively impacted if the UV light is not replaced, assuming regular replacement of filters. The humidity will be removed by the a/c unit regardless of the setting on the thermostat, assuming normal functioning of the system.

Thanks again for the replies.

"The humidity will be removed by the a/c unit regardless of the setting on the thermostat..."

So why does your thermostat even have a Humidity setting- with a Maximum setting of 65%? (The setting when you turned it off the humidity rose a lot and you made no mention of temperature not being controlled...

I'm missing something.

The Carrier Infinity controller has a humidity sensor. In the summer you can set a maximum humidity limit as well as a maximum temperature. Normally the humidity will drop with the temperature as the AC cycles on an off. On days where the outside temperature is in the 70s, and there is high humidity, the controller may turn on the AC to lower the indoor humidity. This is known as cool to dehumidify. If it is very humid, the controller may go below the thermostat set point up to three degrees in order to reach the desired humidity level.

Saltidawg,

"So why does your thermostat even have a Humidity setting- with a Maximum setting of 65%?" That was EXACTLY what I was wondering. What I learned is this: The maximum setting tells the system to go to work - if the maximum setting of 65% were ever reached, it would cause the system to work more to pull the humidity down. By turning the thermostat humidity setting to OFF, I removed simply the maximum setting from the equation. My misconception was in thinking I could set the humidity to 60 or 65% and it would go UP to that level. Not so. And now that I understand just a bit better about the setting and what it's for, I will turn the Humidity setting to ON, and not concern myself about it as long as it's comfortable in here.

And, yes, the temperature was controlled just fine as the humidity went from 45 to 50%. The Carrier Infinity brain controls so much of what goes on, it's hard for mere mortals to know what it's doing and why.

I think the biggest thing I learned is that service techs are trained as sales people, too, (at least where this Carrier Infinity system is concerned) and to question whatever advice they give before purchasing anything. I would have spent more than $1000 on an unnecessary UV system if I had listened to the tech without question. Caveat emptor! Buyer beware!

Thanks for your un derstanding.

So you'll set the Humidity Control to "On" and, say, 45%?? Lol

Mike,

Thanks for your knowledgeable reply. Just learned more about the system and what the humidity setting on the thermostat does. Appreciate the help.

Saltidawg,

I'll set the humidity control to ON, with the maximum humidity up to say 60%, and let the system do the rest. It's been keeping it in the 45-50% range without my interference! I just wanted to know WHY and HOW, at least to understand it a bit better. Mike's answer helped clarify that for me.

Depending on you your climate, but may save some money and be more comfortable by setting he humidity at 50%. I am in NJ where we tend to get summers with temps in the 85-90 degrees with high humidity. I am comfortable with the temperature in the 78-79 degree range and the humidity at 45-50%.

Humidity above 50% could cause mold problems. Don't let the humidity get too high.

The UV bulb can't be that hard to replace if you decide to keep the system operating. The lamps themselves are not that expensive and neither are the ballasts. If you are not all thumbs, you should be able to replace them yourself. They can be had at any lighting supplier. If they need to be ordered, get enough to last a few years.

Unless they illuminate a significant portion of the evaporator, I don't see how they can do anything significant.

Mike,

Sound advice. South Florida is high humidity nearly all year. We set the temp at 80 during the day, 76 at night, and the humidity stays in the 45-50% range. Comfortable enough, and no mold issues.