How a house is built
Heat and cooling
A heat pump moves heat. A furnace makes it. Either one needs a path for air, and this sketch does not size the equipment.
Arrow keys turn the house. Plus and minus, or the zoom buttons, change the zoom. A horizontal drag turns it after you tap the drawing. Reset view returns to the step camera.
The drawing needs WebGL. The notes on the page still stand.
A heat pump moves heat instead of making it by burning fuel. In winter it pulls heat from outside air. In summer it runs the other way. A ducted system uses an outdoor unit, an indoor air handler, and supply and return ducts. Ductless heads skip the ducts and sit in the rooms. A gas furnace makes heat and needs a vent and combustion air. Cooling can be added to a furnace, or the heat pump can do both.
This house has a utility room on the main floor, which is a common place for the indoor unit. The model does not draw ducts or name a capacity. Fresh air is a separate question from heating: baths and kitchens need exhaust, and the house needs a planned path for outdoor air, not only leaks.