Boilers - Hot Water & Steam Heat

There are several efficiency factors to identify in order to evaluate the cost benefits of efficiency upgrades. These efficiency factors are important because high Appliance efficiency - the annual fuel utilization efficiency (AFUE) for various manufactured appliances - does not always generate the highest Return on Investment. First, Thermal efficiency is the output of an appliance (expressed in Btu) divided by the input (expressed in Btu). Example: If a furnace with an output of 80,000 Btu/hr requires an input of 100,000 Btu/hr, the furnace has a thermal efficiency of 80%. Secondly, Seasonal efficiency is how efficient the appliance uses energy over an entire heating or cooling season. This efficiency is important because it determines how much the building owner will pay for fuel over the course of a heating or cooling season. Finally, System efficiency is how efficiently the components of a heating or air conditioning system use energy. Multiple boiler designs, multiple chiller designs, piping changes, the use of efficient pumps, efficient fan motors and microprocessor controls are a few things that can affect efficiency.

For consideration:

A 5 million Btu/hr input boiler firing at 100% capacity, 24 hours per day for 293 winter days will utilize twice the fuel as four 1.250 million boilers firing for the same period. Multiple boilers will all fire at 100% capacity until the indoor building temperature is satisfied. After this is achieved only one (1.250 million) boiler is needed to maintain the building temperature. As the indoor building temperature drops more boilers are fired. An inexpensive boiler management controller operates the multiple boilers. This results in significant energy savings for the building owner.

By improving the thermal efficiency of appliances and designing improvements for existing heating and cooling systems, we are able to improve seasonal efficiency.

When evaluating a property we focus on the system, trying to maximize an economically achievable efficiency. Each individual efficiency factor has an important role in system efficiency. The starting point to Boiler System efficiency is an Energy Survey. An energy survey will establish at what point your building is …a starting point