Solarcrest provided a design for the ventilation system and a full bill of materials to order against. I visited the offices to go through some points of the design and to see some of the components and they were very accommodating for this. I installed the system myself, which was pretty straightforward, and Solarcrest provided telephone support where clarification (for peace of mind) was required. On completion, I had some components left over and Solarcrest took these back and re-imbersed most of the cost (obviously there was a stocking recharge). The system is running continuously and can hardly be heard - you would not notice unless told. The commissioning engineer set a lower rate for night-time and during this time you cannot hear any noise at all. The system automatically boosts when someone is having a shower, resulting in no condensation in the bathroom. Overall we are very happy with the system.