Ill try to keep this as short as possible. I am your typical homeowner with only basic knowledge of my HVAC system.

I moved into a new to me house in 2012. It was built in 2008 with total electric heat pump/electric furnace. We have a separate thermostat for the upstairs and the down stairs but we only have one heat pump and furnace.

The house is 3500 square feet 2 story with crawl space and attic. The furnace is in the garage at the far south end of the house. I had noticed since we lived here that the upstairs is a lot harder to keep warm then the down stairs (I always thought that was odd). Anyway my kids rooms are at the far north end of the house, farthest from the furnace. The air to their room is always room temperature or cooler and their rooms are always cool. I always thought that it was due to the distance the air has to travel from the furnace. It goes up to the attic, across the house and then down to the vents (in the ceiling). Our living room is directly below their bedrooms and I recently got to thinking that the air to our living room basically has to travel the same distance. It goes into the crawl space, across the length of the house and then up into the floor vents. It might be a little shorter distance but not huge. When the emergency heat kicks on when I am in the downstairs I can really feel the warm air and tell it is working, the air coming into the upstairs vents never really feels as warm.

Is this due to the design of our system or is it possible that there is an issue somewhere. The two thermostats we have are pretty basic and you cannot look at them and tell when the system is in emergency heat or not. When I am downstairs I can tell because I hear the thermostat click and the air really warms up. Upstairs I can never tell. The upstairs of the house has two bedrooms at each in and the remainder in the middle is a large single room, probably 700-800 square foot. I assume that a large room like this is harder to keep warm.

Often times when it really gets cold outside (below zero) the system will run constantly and still won't keep up for the upstairs. I can set the thermostat at 68 degrees and it might only get 66 or so in there. I feel like our system is undersized for the size of our house. If I am looking at it correctly there is only one "bank" in the electric furnace as I only see one breaker. I can keep the downstairs warmer then the upstairs.