Systems approach

The Natural Gas Optimization Program promotes a systems approach rather than a component approach when evaluating projects for energy efficiency. A systems approach recognizes that opportunities for energy savings occur in both the supply (equipment and controls) and demand (distribution network and end uses) side of a system. In many applications, the majority of the energy savings are realized in the demand side of the system.

The step-by-step evaluation of a system is conducted with the objective of identifying practical economic measures that satisfy operational requirements while minimizing energy input. For each area of the system, current conditions and operating parameters must be established and energy savings opportunities must be identified and evaluated. Viable options will then be implemented.

Techniques and measures that can be used to improve energy efficiency in each area include:

End use

Eliminate poor or inefficient use of steam, hot water, ventilation air, etc. such as excessive consumption or exhaust rates, leaks, or end uses with higher pressure than necessary.

Distribution network

Implement measures that reduce thermal losses such as replacing leaking steam traps or damaged insulation, venting condensate receivers, or condensate losses.

Supply equipment

Select equipment that operates at higher efficiency by way of upgrading or resizing boilers, reducing blowdown rates, or recovering heat from stacks, blowdown and other waste heat streams with process-specific heat recovery equipment.


Adopt measures that provide automatic control of equipment, that optimize boiler combustion air levels, sequence or stop equipment when it is not required, or adopt measures that allow the supply equipment to better match end use demand requirements.

Measurement and verification

The measurement and verification of energy savings that result from an efficiency improvement project is an important step necessary to confirm that estimated savings have been achieved. Measurement of system performance factors (e.g. equipment efficiency) and operational factors (e.g. hours of operation) before and after a project has been implemented, quantifies the energy savings associated with the improvement.