A buddy of mine has wealthy parents, so I got to stay at this really upscale lake house rental that they always rent out for a huge price every single summer time months. The air quality in this lake area is beyond amazing! The air quality is fresh mountain style air and it would cure any allergies right away just from being in the place! I did lucky for me get to go up there with him more than once, but I have to tell you that it really and truly cracked me up that they chose to run the a/c unit system; Sure it was hot outside this time of year, however in the night those cooling mountain breezes I spoke of swept in off the lake as well as it was magical, my friends parents were apparently afraid of the fresh air for some odd reason which made absolutely no sense what so ever to me to be honest, or maybe they were afraid of the natural ventilation, because they kept their cottage little lake house rental sealed up tight. The a/c unit system there ran 24 hours a day every single day, even when they were out for the morning or afternoon they would leave it running all the time. They told me it had to do with the overall indoor air quality, plus they liked to keep the air circulating constantly. This moved the air through the air filters all through the morning and afternoon, which made the location cleaner plus fresher. To me though I will be honest, it smelled musty and just totally yucky, because there was a complete lack of fresh air, plus the A/C unit system was doing nothing however circulating the old plus stale air around the cottage.