It depends how big the rig is. The heat generated is directly related to the wattage the rig draws. If your attic is too small, or not well ventilated enough, the heat will build up before it finds a natural balance (and that will push your ambient temperature up). Find out what temperature sensors your equipment has (NOT just the miners themselves, your PC can also suffer in overheated conditions) and check them as the summer comes around. Sorry, there's no single correct answer to your question!
Waw thanks I agree with monitoring!
I only have 5 of these usb blockeruptors coming. Opening the windows in the attic will maintain a max temp of about 25 degrees. The question I guess I'm asking is operating at 25 c for 12 hours a day 6 weeks a year too hot for them? I will obviously have a fan pointed at them to maintain airflow. (Most of the year they will be below 19c)
Myrdd
should be fine my gpu input temp is 26c and thay dont get to hot aslong as you have good airfloaw and there not hot to the toutch thay are fine