Some commercial hot water systems may have variable heat load requirements and buffer tanks and calorifiers can help manage this efficiently. When the heating load is very low a buffer tank will store excess heated water, then when demand is higher the buffer tanks stored volume of hot water can be circulated through the system. This helps prevent boiler short-cycling while improving the life span of the boiler, reducing maintenance and saving energy and costs.
A calorifier is an indirect-fired water heater, meaning it does not contain a burner and relies on a boiler or other heat source to heat up the liquid in the heat exchanger coil which then heats up the water contained in the vessel.