The indoor pool is a good place to see how the systems that serve the house are composed into a final design. Behind the composed design are the many systems that make this Net Zero Energy home work. Here all the systems come together: geothermal piping, radiant heat piping with zone controls, pool equipment, geothermal pool heating and dehumidification systems, ERV (energy recovery ventilation) brings fresh air in and heats it with the balanced exhaust air, heat recovery plumbing drains (that recovery heat from bath and shower drain water), solar panel controls, and battery backups.