Technical Overview
The Fuel Economizer takes advantage of the predicament that a building's boiler is sized to provide heat to the entire structure on the coldest day of the year, making it oversized for all other heating requirements. Statistically, this means the boiler is oversized and inefficient over 95% of the time that it is called upon to provide heat.
When a typical thermostat or “Heat Timer” installed on the boiler determines the building needs heat, it sends a signal to turn on the burner. However, the thermostat or “Heat Timer” cannot tell how much heat the building needs, it simply sends a signal that states, "give me heat." The Fuel Economizer, on the other hand, through sensors placed on the boiler, determines how much heat the building is calling for and adjusts the output of the boiler to match the current heating needs.
During the 95% of the time when the boiler is inherently inefficient, the Fuel Economizer moderates the heat output of the boiler and utilizes the residual heat that is a natural by-product of the oversized boiler. Through its patented computer algorithm, the Fuel Economizer calculates how to maximize the store of residual heat. By holding off the start of a burn cycle or avoiding a burn cycle entirely, the Fuel Economizer reduces fuel consumption with no change in comfort.
In order to understand the heating needs of the building, the Fuel Economizer measures the burner run time as well as the rate of change in the heating medium which is temperature for hot water systems, and pressure for steam systems. The calculations are made three times per second, making these measurements dynamic and real time. In order to make the calculations for steam applications, a pressure sensor is installed on the supply pipe and a temperature sensor on the condensate pipe. For hot water systems a temperature sensor is installed on the supply pipe. The Fuel Economizer's patented algorithm uses the information gathered from the sensors to determine the most efficient cycling pattern of the boiler.
In the case of a boiler that is also used to produce domestic hot water, an additional sensor is installed on the domestic hot water supply pipe. The information gathered from this sensor makes the boiler much more efficient in its heating of hot water with no impact on the temperature of the water needed to fulfill the demand.
The Fuel Economizer will increase the efficiency of your building’s boiler and works with the existing thermostat or “Heat Timer” currently installed on the equipment. The Fuel Economizer is wired in series with the thermostat or “Heat Timer,” and is placed in the circuit between the thermostat or “Heat Timer” and the burner.
Installation takes approximately four hours per boiler. In situations where there is more than one boiler, a Fuel Economizer is required for each boiler. There is no follow up maintenance or adjustment required.
The diagram below illustrates how the savings are achieved. The diagram is an example of a single burn cycle. Here, a call for heat is delayed for 7 minutes (from minutes 12 through 19). The time it then takes to recover from the temperature it would have been without the Fuel Economizer is 3 minutes (from minutes 20 through 22). The net savings, therefore, are 4 minutes or 14% for this illustrative cycle.
