Disappointing is about the best description. Solarcrest came recommended and the initial phone calls were very positive offering good options and most importantly lots of support. The supply was fine and the fitting was straightforward enough but we are finding the unit draughty and noisy in use and frequently turn it off which defeats the point.. We think there are issues with the design and possibly with the machine, we have tried numerous times to resolve it with both solarcrest and Vent Axia and have managed to get it so we can mostly put up with it but still end up turning it off at times. In particular the commissioning was a total waste of money (£450) the guy spent 30 minutes tops actually doing anything none of which seemed to be anything technical and I ve had to change lots of elements to get it to work for us, but they won't give you the paperwork you need to get the completion SAP done without it.