thank you very much for that link -- most of the other links mentioned earlier about humidity in this thread have either expired or denied me access. i was curious as to whether an attic fan might be a solution; it appears from the linked article that it is not. i don't think moving our air handler out of the attic is an option space-wise. do you believe closing the roof vent would be helpful? am i going to create more problems for myself if we install a piece of plywood over the vent from the inside? it seems much of the advice i've read about high humidity areas is to seal off the attic area and reduce insulation as opposed to increasing it or using reflective barriers. it is all a bit confusing.

Common Problems With Air Conditioning. Open Windows One of the most common problems with the cooling system in your home is occurs when doors and windows are left open. You might be surprised at how often just being vigilant about doors and windows can significantly improve the cooling process for your home. Low Refrigerant Refrigerant is the chemical that cools the air within your AC system. Low levels of refrigerant could mean there is a leak, or an actual problem with the refrigerant system. If your AC system needs to be recharged, most of the time that suggests there is a leak. Leaky Ducts, Bad Air Flow Leaky ducts or improper air flow are another very common culprit for why your AC is not cooling properly. Inconsistent temperatures often are an indicator that this is the problem. If there is a leak somewhere in the line then the cool air that is moving from your unit through your home is not making it all the way to where it needs to go. Filters and Coils Check your filters and coils. A dirty filter or coil will restrict your air flow and keep your machine from running at peak efficiency. Clogged Drain A clogged condensate drain on your unit can cause loss of efficiency and cooling. It is best to get a certified HVAC technician to check this for you, it is bit more technical and it is better to be safe than sorry. If you break something it could cause a much more expensive repair later on. Outside Fan The outside fan is responsible for conveying the heat from your home to the outside air. If the fan on the outside isn’t performing correctly, the proper heat transfer cannot take place, the air conditioning compressor may overhead and trip the safety overload. Solution The best and most effective way to prevent these problems is by participating in a preventive maintenance program. If you would like help with your air conditioner from a professional.

I guess adding the basement wouldn't shorten the cycle, but it would lengthen the time between cycles. A/C is set at 75, and basement is 69. Blending bsmt air with living space upstairs would cool upstairs even without any a/c on, if I didn't mind the extra humidity and radon. The only difference, as I understand it, between an air conditioner and a dehumidifier is that the heat from the a/c condenser can be separately vented if desired. An a/c's dehumidification should equal a dehumidifier's, just as an a/c cools as well as a heat pump - all the same machine, except how the plumbing and venting is arranged. The only other considerations are that if it is vented, the a/c will cool the bsmt, as well as drawing in moist outside air, both increasing RH. In other words, the dehumidifier (or a/c in unvented dehumidifier mode) achieves part of its dehumidification by heating the space, or at least by not cooling it. I think if the a/c unit can operate at temps in the 60s, it is preferred, as it has the flexibility of running in cooling mode (vented) or dehumidifier mode (unvented). I'm also thinking it might be more efficient, as EER is reported (even tho not great), while there's not much reason for dehumidifier mfr to make unit efficient.

To each his own. Being retired, my income arrives at my bank account monthly, whether I do anything or nothing, so I have available time, which many may feel that they do not. While I referred to this as a "money saving tip", I'm also aware that in many parts of the world, we're hugely short of water ... and becoming more so. For example ... California is the fastest growing state in the union (or was, a while go - my knowledge may be somewhat out of date). And they ... and Arizona, another fast grower ... are really short of water. If those who could do so comfortably were to use already-used water again for a less restricted purpose, the total use of water in a city would be somewhat reduced. I've said to some Canadians, "The crucial liquid of the last century was oil. In this century, it will be water. One of these days, when California, getting really short of water, proposes that we ship some of ours down between the mountain ranges to them ... ... if we say, 'No' ... Do you know what a Marine's uniform looks like? Do you want to find out?" The problem is much deeper than we've been considering, up until now. ole joyful