A Buffer Tank is a large volume water storage vessel that moderates temperature fluctuations and stabilizes system operation in heating and cooling systems. Also called a thermal mass tank, it absorbs excess heat production or cooling capacity to prevent short cycling. Buffer tanks typically hold 40-100 gallons of water per ton of system capacity.
Technical Function
Buffer tanks maintain minimum return water temperatures between 50-55 degrees Fahrenheit in heating systems and maximum temperatures below 100 degrees Fahrenheit. They require 1-3 minute detention time for proper heat exchange. Tanks include internal baffles to separate supply and return connections, promoting stratification.
System Benefits
Buffer tanks enable increased boiler efficiency by preventing on-off cycling of 10-15 minute intervals common in small systems. They allow heat pump systems to operate at design capacity without rapid cycling. Buffer tanks also reduce peak demand charges on heating systems and improve overall system response to varying loads.