This SunMaxx20 evacuated tubes set runs in parallel with a total of 6 SunMaxx20 systems for a total of 120 tubes. These tubes collect enough heat to power this small office building of 20 employees and a 5000 square foot building allowing. The hot water runs down through the roof into the radiant floors and baseboard which acts as the heating storage component making the hot water last for hours well in through the night. When the temperature drops….the existing hot water boiler system kicks on to maintain the water temperature at a certain level. In this building the hot water bill went from 800 per month to 200 without SRCC credits.