I live in Maryland near northwest DC. Our AC isn't working and we are about to sign a contract for a York hybrid heat pump and a new gas furnace. The outdoor heat pump is designed in a way that it exchanges with the outdoor air from the side of the unit and not from the top (which I believe is a more traditional design).

The HVAC contractor who only uses York units wants to install it on our brick wall. This is near the bedroom. I have read that while a heat pump unit may be pretty quiet that when working hard it can create a vibration through the wall which may or may not be an annoying sound for the occupants in a nearby room. I am a light sleeper so I thought it may be best to install this on the ground. The contractor insists that no one has ever complained to them about vibrations from a wall installment and that this would not be a problem. They will however, put the heatpump on a 2 - 3 " thick pad on the ground if we want.

I have read that heatpumps do not work well, can shut down and even be damaged when covered in snow. When I asked if the heatpump could be raised from the ground (units are often raised 6 inches to 2 feet depending on an area's typical snowfall) the contractor said that this is not necessary because when its cold enough for snow the furnace will be working and we can always switch the heat to furnace mode anytime. One of the main reasons we got the heat pump is to help the environment. Ideally, I do not want to have to guess how much it might or might not snow in the middle of the night and switch it to the furnace when I really don't need to. Or suppose there is a four inches snowfall and the next day temperature is in the upper 30s or 40s - I won't be able to use the heatpump unless I shovel around the heatpump and clear it.