When I posted this I spoke to 8 very good fanciers who use atx or similar including Frank Bristow , so I went to visit 2 lofts and have to say you wouldn't know there was heating on just a very dry climate inside the loft which is what I aim to have in my loft , I am under no illusion it will not make my birds win but I believe it can help keep loft and birds in good condition. I will let you know how I get on . Ps my national birds will still be left to nature on open hole . Colin