Why Turndown Ratio Matters

In their smallest form, devices intended to heat water or other fluids using a chemical fuel (coal, gas, oil, electricity etc.) are usually thermostatically controlled. When the desired operating pressure/temperature is attained, the thermostat turns off the heat source. When the pressure/temperature has fallen (usually to a pre-determined level), the thermostat turns the heat source on. The heat source has only two states, ie on or off. This is undesirable in all but the smallest devices as the fluctuations in pressure/temperature lead to inefficiencies in fuel combustion/consumption.

If the heat source can be made to modulate, there can be considerable savings in fuel due to combustion processes and heat/wet side temperature differences. Pressure/temperature output can remain more constant which may be of benefit.

If it is only possible to turn the output of the heat source down to (for example) 50% of its maximum. This would give a turndown ratio of two. If the heat source could be turned down to 25% of its maximum value, the turndown ratio would be four and so on.

This means that if pressure/temperature falls, the heat source is progressively turned up.

The HTP Elite boiler has a best in class 6 to 1 turndown ratio which provides the high efficiency performace that today's cunsomers want. Made in the USA, the Elite boiler is energy star rated and built with quality. The Elite boiler comes in six models ranging from 80,000 btu - 399,00 btu making it suitable for any application.