This is our very fancy, highly efficient, heat pump water heater. We are an all electric house and this Airgenerate Airtap Hybrid meets the strict energy requirements required by the organization that will be monitoring our house. It captures heat from the air to heat the water inside with a backup heating element for high use times.
Neil actually installed our boiler for the radiant floors. The main heat in the accessory dwelling unit (ADU aka apartment) is from the in-slab radiant heat. 
The manifold for the ADU is in the closet. You can see the tubes sticking up in the above photo. Actually if you look closely at the above photo you can see the in and the out tube going to the ADU manifold. We have 2 zones for the lower level of the house. The ADU and our main entry, office areas, and laundry.
