The Homemade Heat Pump Manifesto

[bigsmile]

I just recall something when I read about DX hp. I think the oil return problem isn't restricted to vertical arrangement of coil. Long run of horizontal coil may also have this problem. To furcilitate oil return, it is usually recommended that horizontal runs of copper tube be sloped a little. This may be difficult to arrange if refrigerant lines are directly used for floor heating.