Hello. You have 2 basic choices. A ductless mini-split system that can cool one or a few rooms. They take up very little space and are generally variable speed compressors, 18+ very high SEER, quiet, compact, and a little pricey. They are very popular in Europe and some Carribean islands. The technology is proven and solid. There are also PTAC units that are found in motel rooms - they can be either heat pumps for heat/ac or just straight a/c. They are basically a big box that penetrates an outer wall and tends to be permanently installed. Good luck.

Is the 50% RH too high for you, or are you just curious about the increased humidity? If you want lower humidity, assuming you have a multiple speed unit, try setting the fan on a lower speed. That will increase the unit's dehumidification capacity at some expense to its cooling capacity. It may take longer to cool the room, but the humidity should be lower. Dropping the temperature five to seven degrees in one hour sounds like over cooling to me. Could you describe the unit's operating conditions. How often does the unit cycle as it is now, and what are the rough percentages of compressor on and off times? What is the outside temperature during the time you are using the unit, and what is your desired temperature for the room? Are you getting any condensate out of the unit on the outdoors side?

Haha, well now this makes sense. I'm in Silicon Valley and have more than enough exposure to engineers and tech types who think they can understand and improve just about anything with homespun whizbang. They far too often fail but have trouble admitting that. Usually the damage isn't too costly. That may not be so here. JoeQ, your clever "system" may bring your furnace to a premature end of life. Or may have already. And that can lead to carbon monoxide emissions in your home. Or may have already. A new furnace may be a few thousand dollars. Health damage from carbon monoxide, hard to quantify. Your "system" isn't performing its most basic requirement, which is to properly control the furnace without damaging it or risking your health. Declare your experiment over and call an HVAC company to get your stuff working right, the traditional way. Good luck.

What Is Air Conditioner Short Cycling? https://www.centralacwarehouse.com/ While the average air conditioning cycle lasts around 20 minutes, sometimes your air conditioning system can go through cycles too quickly—an issue known as “short cycling.” Short cycling is a term that means the air conditioner turns on and off in short bursts and does not heat or cool your house properly. An AC system that short cycles can become less efficient, resulting in increased energy bills and excess wear-and-tear, and can result in reduced comfort for your home. Troubleshooting the cause of short cycling should be performed quickly to prevent any further damage. If your air conditioning system is short cycling, here are four potential culprits. Causes of Air Conditioner Short Cycling. 1. Low Refrigerant Level: If the refrigerant is low in your air conditioner, your AC unit will not be able to properly cool your home. This inability to work properly will put stress on various components, causing them to work harder and in turn can cause your AC system to turn on and off irregularly. 2. Oversized Air Conditioner: If your air conditioner is too big for your house, it will cool the house very quickly and then shut off. This leads to higher energy bills, more maintenance calls than usual and can cause uneven cooling in the house. 3. Iced or Dirty Evaporator Coil: This is a common cause for people that have not had routine preventive AC maintenance performed on their air conditioner. The evaporator coil in your air conditioner removes hot air from your house, and when your AC unit can’t take out the hot air effectively, it has to work much harder to get the job done. This can lead to the air conditioner overheating and shutting off. 4. Dirty or Clogged Air Filter: If you don’t regularly replace the air filters in your house, the buildup can cause the air conditioner to work harder than necessary. When your air filter becomes too bogged down with dirt, dust and other microscopic particles, your air conditioner has to work harder to compensate for the lost airflow. This puts excess stress on the parts that operate the blower and compressor. These parts can overheat causing your air conditioning system to short cycle or even potentially break down resulting in costly repairs.