Description of Program
The principle goal of the General Electronic Enterprises, Inc. Energy Assessment Program is simple: to define and quantify your building's MINIMUM HEAT ENERGY REQUIREMENT.
Once the minimum heat energy requirement is established, you will have a basis for judging any heatingrelated conservation project, whether it involves insulation, heating system efficiency or controls. Instead of ill-defined "savings"---from what? ---you will have a well-defined performance target.
The formula is based on the control principle of Thermal Energy Replacement'm which we have successfully applied to over 8 million square feet of space in more than 160 buildings under PACE control. Thermal energy replacement is the continuous matching of heating system output to the instantaneous heat loss of the building envelope. The continuous output enables the operator to find the building's true start point for heating (which determines the degree day base) and the correct system response percentage (which determines usage).
What is the instantaneous heat loss of the building envelope? It is basically the transmission loss at a given temperature difference. It does not include ventilation or infiltration, and it does not depend on indoor
temperature settings. What is the correct reference temperature? It is the outdoor temperature above which no heat is needed, and below which a degree of heat is needed. This is the balance point for heating. With PACE control it is also the start point, which determines a new degree day base.
The PACE control formula and the heat loss calculation are one and the same. This accounts for the accuracy of the energy use projection. The only exceptions are:
(a) weather variation: variation from average conditions may increase or decrease actual consumption from calculated;
(b) wind effect: by increasing the heat loss from exterior surfaces, increases actual consumption from calculated;
(c) solar effect: by passive solar heat gain, decreases actual consumption from calculated. While the PACE System responds to these factors, the computation does not include them.
Comparing: The results of the Energy Assessment Report may be stated in kilowatt hours or total Btu requirement for any period. These figures may be used for comparing measured or estimated performance of various systems.
Monitoring: In the case of forcedair systems, the load necessarily includes the ventilation requirement,
because the heater must run until the indoor temperature rises to the thermostatic setpoint. The extent of the wasteful "fighting" between the heating and cooling systems can be quantified by subtracting the minimum heat energy requirement from the total (measured or estimated).
Measuring Efficiency: Fuel-fired systems have heat transfer losses and heat transmission losses which add to the input Btu requirement without contributing to the delivered heat. The ratio of total input Btu to the minimum heat energy requirement is a good indication of over-all heating system efficiency.
Flagging Control Error: Typically, much heat is lost in an air-conditioned building due to control error. An unusual increase in heat output due to tampering or mechanical failure is simply "cancelled" by more cooling. Comfort is not improved but the building owner pays twice, once to overheat and again to re-cool. The minimum heat energy requirement can be generated by the day or hour, and compared to actual operating results to flag control error.
Projecting Costs: If the PACE System is to be used in new construction or a conversion project, the monthly heating cost, including consumption and demand charges, can be projected with accuracy. This is beneficial in financial planning as well as in comparing mechanical systems.