Installation instructions are for F Gas registered firms and engineers only. All Qualitair cellar cooling systems are pre-programmed to maintain a cellar temperature of 12C (Plug & Play) the electronic control can be adjusted down to 2C providing the room is sized with the system, Standard systems only, Slimline systems cannot operate below 11C. The Q35CU and Q50CU outdoor condensing units are for both Q35/QSL35 and Q50/QSL50 Standard and Slimline indoors. All units are R410a gas with R32 and option. Qualitair offer technical advice by phone or email.