Energy Savings: Boilers

1. Inspect and Maintain Boilers
   The costs of properly maintaining boilers are fully recovered in fuel savings. To ensure peak efficiency, remove scale, replace leaky tubes and flanges, remove damaged insulation and control linkages, and recalibrate controls.
   
   
2. Install an Economizer to Increase the Efficiency of a Boiler
   To increase the efficiency of a boiler by 2 to 3 percent, install an economizer. This device preheats the feed water (returned condensate). In the case of a 250 horsepower boiler, an initial investment of $6,000 provides an annual savings of more than $3,000.
   
   
3. Keep Boiler Insulation in Good Condition
   For peak efficiency, repair or replace damaged or missing boiler insulation.
   
   
4. Minimize Excess Air in Boiler Operations Using 02 Trimmers
   To increase boiler efficiency, minimize excess air using O2 trimmers which adjust the amount of air supplied to the burner. Most boilers operate with more air than is required for the combustion process, wasting energy.
   
   
5. On Any Large Boiler, use a Blow-Down Heat Exchanger
   On any large boiler, use a blow-down heat exchanger to preheat the make-up water going to the deaerator. This measure conserves energy by reducing the energy required to preheat the make-up water and by partially cooling the blow-down water prior to discharge to the sanitary server.

Water Heating:

1. Heater energy effciency
   Although a hot-water system accounts for only about 4 percent of buildings total energy consumption (this figure is higher in buildings having laundry or restaurant), increasing the system’s energy efficiency is nonetheless worthwhile. The heater’s energy efficiency can be raised; the storage tank, supply piping and recalculating piping can be insulated to reduce energy losses due to radiation, convection and conduction; water temperature guidelines can be strictly observed; and tenants can be encouraged to conserve. Energy savings can be achieved by placing water heaters close to usage points rather then installing one central generation tank and long runs to hot-water piping. To determine whether the installation of local units would be advantageous, analyze the building’s hot water demand patterns. Next, estimate the existing systems total energy losses; then energy saved is the sum of the reduced distribution losses and the increase in the average generation efficiency of local units, as compared to a central system.
   
   
2. Reduce generating and storage temperature levels.
   Reduce generating and storage temperature levels to the minimum required for washing hands – usually 105°F. Boost hot-water temperature locally for kitchens and other areas where it is needed, rather then by providing higher-than-necessary temperatures for the entire building.
   
   
3. Installing a heat reclaimer
   If there is a need for process heat within an operation, a heat reclaimer can be installed in the boiler stack of an economizer. A heat reclaimer is similar to an economizer in construction and installation. However, reclaimed heat is used to a fluid other then feedwater. This heated fluid then may be used in some other process. Process water is passed through the reclaimer to recover the heat in the exhaust gases. Because of the high temperature rise possible in the process water, the amount of heat transferred with the reclaimer can be considerably greater than with an economizer. Exhaust recovery systems and economizer should be used only when the stack temperature exceeds 350*F. If the stack temperature is allowed to fall below this level, corrosive fluids may condense and damage the stack and possibly the boiler.
   
   
4. Reducing water pressure
   If water pressure exceeds 40 to 50 pounds, consider having a plumber install a pressure-reducing valve on the main service to restrict the amount of hot water that flows from a tap.