I leave my HV SE here in Mesa all year. In the summer we set the AC to 90d and it seems to do fine. It does get very dusty here so I suggest making sure it is covered well. I just cleaned mine yesterday and it had a lot of fine dust on it. Our AC broke one year and when I came down to check on our place the temp was over 120d inside the house. I don't know how long the house had been at that temp, but it took over a week to fix.