A caravan modular hot water boiler heating system or steam boiler heating system consisting of 2 or more compact modules installed in a series offers significant advantages in terms of installed cost, efficiency and reliability. A boiler operates most efficiently when its capacity is being fully utilized to provide heat or hot water. A typical single boiler's full output is generally needed for less than 20% of the year, when the coldest weather occurs. The rest of the time it wastes fuel because it fires at full capacity to meet a partial load.

Advanced controls monitor outside conditions to modulate system water temperature. Caravan microprocessor system controls monitor the outside air temperature and the temperature of the water circulating through the building's heating system. As the outside temperature rises or falls, the Caravan system responds by lowering or increasing the system's water temperature. It automatically fires additional modules to meet demand or turns them off as demand decreases. The SC Series controls are so advanced they use computer logic to step-fire boiler modules, maintaining more consistent building comfort.

By step-firing just enough modules to meet demand, Caravan systems operate efficiently through the entire year. Caravan modules are energized one at a time as needed. Each module's full capacity is utilized before the next module is energized.