<html> <body> Hi Stan.                I think the results of the data loggers show a lot.    This graph is a sample of two closely matched C3 grands in a teaching studio at the University. The pianos sit side by side . Both pianos had calibrated data  loggers fixed in identical positions on the centre beam. Humidity and temperature measurements were made every 15mins 24/7. One piano with cover, one without. The covered piano had the damp chaser unplugged for a few days. Tuning changes were also made on a weekly basis, but I will share that data at a later date. You will note that the temperature of the covered piano is one to two degrees higher because of reduced circulation, but the humidity is on average 10% higher. My research has shown that pads should be changed every 60days for maximum efficiency. Just some teaser information. I will get around to collating and publishing more extensive data later. Point.  These bottom covers work, now we have to collectively find better ways to install them. Regards Roger   </body> </html>