So! after running my miners in my loft for the past 3 days. They're both steady - one at 212.5 hashing at 430 and one at 250 hashing at 490. My main concern about them being in the loft was the temperatures. The loft gets to around 40c in the day time with both of them whirling away - both of my S3's sit at around 48-50c during this period and seem happy! no x on my chips, straight o's throughout!