[tuccillo]

Relative humidity is a misleading quantity because it is a function of not only the amount of absolute moisture in the air but also the temperature (and pressure). Relative humidity is defined as 100% when the temperature is equal to the dewpoint (a measure of the absolute amount of moisture in the air). Relative humidity is the amount of moisture expressed as a percentage of the amount of moisture that would be needed for saturation of the air. Therefore, with the same amount of absolute moisture in the air the relative humidity will change with temperature. A relative humidity of 100% at 50F feels much different than 100% at 77F and reflects a much different amount of moisture in the air. A relative humidity of 100% rarely occurs around here with temperatures above 80F. The reason for this is that is very difficult to have a dewpoint over 80F. Situations such as 95F temperature and 95% relative humidity never occur.

This creates some interesting situations. For example, with a dewpoint of 77F and a temperature of 95F you have a relative humidity of 56%. This doesn't sound so bad but is actually quite miserable. If the temperature drops to 77F you then have 100% relative humidity. Therefore, with the same amount of absolute moisture in the air you can have wide variations in the value of relative humidity. Dewpoint is a better parameter to watch since it reflects the actual amount of moisture in the air. Relative humidity is, however, important if you are concerned about mold growth.

Relative humidities will generally be quite high in the mornings as the temperature will drop to the dewpoint (and dew will form). Once the temperature starts rising the relative humidity will drop even though the same amount of total moisture may be in the air.

During the summer (around here) when it is hot and humid, you can generally expect that your AC will reduce the dewpoint inside your house to something around 60F, plus or minus. Typical summer dewpoints around here are 70-78F. That difference may not sound like a lot but it makes a huge difference in how you feel. Generally, ACs will have a 20-22F drop across the coil. If the temperature inside your house is 78F then the air coming out of the vents will be around 58F. Not all of the moisture can be condensed so you will wind up with around a 60F dewpoint, plus or minus.

Originally Posted by SFSkol

Very interesting.

From AccuWeather web site for The Villages right now;
Humidity: 94%
But, that's outside.
Could it be that since you have it set at 77 it has over time reduced the interior humidity? I've been using fans during the evening which of course sucks in the humid air. Guess I should get a hygrometer.

Humidity Averages for Florida in June - Current Results

[Allegiance]

Originally Posted by Toymeister

Original poster (OP) you do realize that a 'State of the art' thermostat costs less than a dehumidifier? Far less, 120.00 for a sensi by emerson, found on amazon. It even dials changes the temp if I am 3 miles from my home, and cools it down as I appoach home. I have not seen any weather get where a temp greater than 84 has a humidity of over 60. I have been watching 8 months.

I have the sensi, what device do you use to detect your 3 miles location and activate thermostat?

Thanks

[Toymeister]

Originally Posted by Allegiance

I have the sensi, what device do you use to detect your 3 miles location and activate thermostat?

Thanks

I loaded the app into my phone as well as my wife's. Once we are both over three miles away it sets back the temp by three degrees. This is optional function, of course. Other brands of smart thermostats can do this as well. Sensi is simple made by thermostat people. Others like the nest are made by silicon valley folks,meaning great software, not as great thermostat. But still very nice as it should be at twice the cost.

The thermostat functions are available remotely by free software (the phone app). The more advanced functions required a smart hub which cost 70-100. For a average homeowner you will not need this hub. The location away function does not require a hub. The location function was part of a software upgrade about a month ago.

[tbluemling]

Originally Posted by sfskol

i'm new to the villages and am wondering if anyone has efficiently and economically utilized both an air conditioner and dehumidifier, to combat this heat. If so, what technique is best.

can't say enough abou chuck farrell honest, prompt and economical

[crash]

Originally Posted by Toymeister

Wildwood this moment is 81% humidity.

That is the humidity outside what everyone is talking about is the humidity inside. You can not get that from a radio station or the internet.

[retiredguy123]

You can buy a humidity meter at Home Depot for about ten dollars which will measure the relative humidity in your house. But, a fancy thermostat connected to your cooling system will do nothing to control the humidity in your house. You would need to use a dehumidifier which will overcool the air, removing moisture, and then reheat the air to the desired temperature. The relative humidity is the amount of moisture in the air "relative" to the amount of moisture that the air is capable of holding at the temperature of the air. So, if the relative humidity is 50 percent, it means that the air is holding half of the amount of moisture that it is capable of holding without becoming saturated.

[Toymeister]

Originally Posted by retiredguy123

You can buy a humidity meter at Home Depot for about ten dollars which will measure the relative humidity in your house. But, a fancy thermostat connected to your cooling system will do nothing to control the humidity in your house. You would need to use a dehumidifier which will overcool the air, removing moisture, and then reheat the air to the desired temperature. The relative humidity is the amount of moisture in the air "relative" to the amount of moisture that the air is capable of holding at the temperature of the air. So, if the relative humidity is 50 percent, it means that the air is holding half of the amount of moisture that it is capable of holding without becoming saturated.

An a.c. Unit does remove humidity, a fancy thermostat gives you more information on how the a.c. Is performing in your home. There are hundreds of websites that discuss this. A.c. Dehumidifies passively, but you will probably be running your a.c. Anyways. So you will dehumidify even if that is not what you intend to do. The question is is that low enough humidity for you. If you have spent time in a hotel or just about any other public building you have a point of reference if the humidity relief is great enough.

[retiredguy123]

Originally Posted by Toymeister

An a.c. Unit does remove humidity, a fancy thermostat gives you more information on how the a.c. Is performing in your home. There are hundreds of websites that discuss this. A.c. Dehumidifies passively, but you will probably be running your a.c. Anyways. So you will dehumidify even if that is not what you intend to do. The question is is that low enough humidity for you. If you have spent time in a hotel or just about any other public building you have a point of reference if the humidity relief is great enough.

An a.c. unit does remove humidity as it cools the air, but the primary function is to lower the temp. A dehumidifier is different because it's primary goal is to lower the humidity without lowering the temp. To do this, it first lowers the temp to remove moisture and then reheats the air back to the original temp, so the end result is a lower humidity with no change in temp. An a.c. unit alone will not do this.

[Toymeister]

Originally Posted by retiredguy123

An a.c. unit does remove humidity as it cools the air, but the primary function is to lower the temp. A dehumidifier is different because it's primary goal is to lower the humidity without lowering the temp. To do this, it first lowers the temp to remove moisture and then reheats the air back to the original temp, so the end result is a lower humidity with no change in temp. An a.c. unit alone will not do this.

That is almost true, dehumidifiers generate heat by running the compressor. You are correct in that the effect of the coolant under pressure is cold, when it expands it generates heat, it is not heated. The compressor running does generate heat, just as any electric motor running does. Again this is explained it you Google it. All of this begs the question for the original poster, will the air which is dehumidifier by the central a.c. Dry enough to satisfy him/her.

With the current weather conditions a home with A.c. Set between 70 and 80 will have a relative humidity of 50 to 60. Most Americans find this completely acceptable particularly if it is close to 50. But I can understand someone from a desert region may want a dehumidifier over ac. Or in addition to ac.

[tuccillo]

Not quite right. When the refrigerant expands it cools. When it is compressed it heats.

Originally Posted by Toymeister

That is almost true, dehumidifiers generate heat by running the compressor. You are correct in that the effect of the coolant under pressure is cold, when it expands it generates heat, it is not heated. The compressor running does generate heat, just as any electric motor running does. Again this is explained it you Google it. All of this begs the question for the original poster, will the air which is dehumidifier by the central a.c. Dry enough to satisfy him/her.

With the current weather conditions a home with A.c. Set between 70 and 80 will have a relative humidity of 50 to 60. Most Americans find this completely acceptable particularly if it is close to 50. But I can understand someone from a desert region may want a dehumidifier over ac. Or in addition to ac.

[crash]

Being fro Ca. I find the 50% Humidity at 76 degrees that the air conditioner delivers perfectly comfortable. I did not think I would and looked into a dehumidifier but find it not necessary.

I do think you need a thermostat that has humidity reading though especially if gone for long periods of time. Mine is hooked to the internet and I set my thermostat to send me a notification when humidity exceeds 65% and then turn down the thermostat to lower the humidity. Normally set thermostat to 84 degrees when I am gone to save money.