What is the minimum heat setting? I want for a workshop to keep just above freezing (40*F).

Thank you for your question. During heating this unit has a max indoor temperature operating temperature of 80.6 degrees Fahrenheit and a minimum operating temperature of 44.6 degrees Fahrenheit. During cooling this unit has a maximum indoor temperature operating range of 69.8 degrees Fahrenheit to 89.6 degrees Fahrenheit. For more assistance, please give us a call.