Once again you are 100% wrong. Warming the air with a heat pump reduces
relative humidity because warmer air can hold more moisture. It does not
remove ANY moisture. It does nothing to
absolute humidity, which is the actual moisture content of the air. Heat pumps in AC mode actually remove moisture from the air.
Life is too short to continue this discussion. Talk to the folks that service your home heat pump and LP systems. They will enlighten you.
To Summarize:
1. Heat pumps in heating mode (that simply recirculate inside air) and vented combustion heating sources (oil, gas) that pull the combustion air from the outside (RV LP furnaces) neither add nor remove moisture from the heated space.
2. Unvented combustion sources, such as gas stoves, gas fireplace logs, and freestanding kerosene heaters add moisture to the heated space.
3. The air in heated spaces becomes dry because of the exchange of cooler, drier outside air with warmer, wetter inside air by such things as vented bathroom fans, clothes dryers, and stove hoods; by opening doors and windows, AND vented combustion sources (oil, gas) that pull the combustion air from the heated space (inside) and vent the combustion gases to the outside.
I will stack my credentials against yours: B.S., M.S. Chemical Engineering. 30 years as a licensed professional engineer.
OK, absolutely ludicrous response. Of course the air circulation is removing the moisture. But then, I am only a patient who has studied this for the past 47 years or so, with professional help from physicians and from HVAC folks.
Given the fact that I also have extensive knowledge of HVAC and one son who has done it most of his working life - I don't need any further education from you.
I also decline to an ongoing running argument/debate. My complete statements are 100% correct. Everyone I know has a humidifier installed on their heat pump in the home. Yes. It is necessary to protect health, home and contents.
Just for grins I remember when we purchased our second Tiffin DP while speaking to Bob Tiffin we were discussing travel to some of the Western states. He stated to always run a humidifier while in those arid areas to prevent the wood inside the RV from being damaged. Me? Heck, I'm more concerned about my health.
The average healthy male gives off about 200 milliliters of water during an 8 hour sleep period, breathing. Yes, that is true and two people and a dog will definitely produce moisture on the windows in some conditions, temperature drop at night outside etc. You can actually call those functional bodies humidifiers. Normally opening a vent and allowing the air exchange will prevent the moisture accumulation.
As far as debating the technical reasons for a heat pump lowering the humidity in a home lets just admit it happens, which it does. I completely understand the technical functions of a heat pump and using one will lower the humidity in the home - enough said, whether you want to admit that or not does not matter it is just a known fact. It is not removing humidity the same way the unit does in cooling but it is drying the air to desert levels. It is certainly the exchange of air and air movement.
As far as using an unvented LP heater inside the coach - some are actually doing that but unless they got buried they opened a window. The debate is over.