Energy Saving Ideas
The items below are a list of Energy Saving Ideas. These are ideas that make sense for most buildings and have realistic payback periods. Hawkeye continuously reviews new energy saving ideas and updates this list on a regular basis. Hawkeye endorses the ideas listed below and will not list ideas that have long term paybacks. Generally the items listed below will have a payback of less than three years. Look these ideas over and contact Hawkeye Energy Solutions today for more information.Chillers, Boilers and Cooling Towers – Replace aging systems with today's smaller more efficient systems. In many cases, existing boiler and chiller plants are significantly oversized. Sometimes twice as much or even more. Unfortunately, oversized equipment significantly reduces operating efficiency. Have boilers serviced including a check of flue gases to make sure the units are operating properly and are not using too much excess combustion air. Consider upgrading the controls and drives on your cooling tower to adjust the speed of the fans based on the load.
Waste Heat Recovery – Recover, recuperate and/or regenerate waste heat from compressors and processes such as high temperature furnaces and high pressure steam systems. Many processes and every day compressed air systems have waste heat ready to be used for comfort heating, domestic hot water or any number of other uses. Any system that discharges flue gases above 450F is a good candidate for heat recovery. Systems above 1200F are very good candidates.
Combustion Controls – Upgrading your combustion controls for boilers and process burners can result in a payback of less than 1 year. New digital combustion control technology can provide precise combustion airflow and gas control that eliminates waste and improves efficiency. In addition, switching to modulating burner control from simple on/off control can improve equipment life and increase efficiency.
Energy Recovery – Take advantage of excess exhaust air and pre-condition required make up air with any number of today's cost effective energy recovery technologies. This includes heat wheels and air to air heat exchangers.
Steam Systems – Many steam systems offer excellent opportunities for recovering waste heat. Consider waste heat recovery on any steam system 80 psig or greater. The payback can be less than two years. Also consider changing steam to hot water heat exchangers with direct fired units. Efficiencies can increase from 70% to 90%. Don't forget to check your steam traps. Steam traps eventually leak and cost you money. Fixing steam traps may have a payback of less than a month. Finally, don’t let that steam condensate go down the drain. Correcting or adding condensate return is a must.
Variable Speed Drives - Save energy and protect existing constant speed motors with variable speed drives (VFD's). Also consider using VFD's for balancing instead of using a balancing valve. For most variable torque motors, changing the speed to match the actual load reduces energy usage exponentially. For example, consider the following annual cost differences for reducing the speed of a 100 horsepower fan motor operating for 2000 hours per year.
| Percent of maximum speed |
RPM | Horsepower Usage | Cost ($) |
|---|---|---|---|
100% |
1725 |
100 hp |
$11,936 |
75% |
1294 |
42.2 hp |
$5,036 |
50% |
863 |
12.5 hp |
$1,492 |
33% |
575 |
3.7 hp |
$442 |
ECM Motors – ECM stands for Electronically Commutated Motor. ECM motors are ultra high efficiency programmable brushless DC motors that use a permanent magnet and a built in inverter. These motors can reduce energy costs by up to 70% compared to industry standard permanent split capacitor (PSC) motors. Not only are these motors more efficient but they reduce maintenance costs and offer a turn down ratio of up to 80% without the need to install a VFD.
Fans, Pumps and Motorized Systems - All motors 1 hp and above operating 2000 hours per year (or more) are good candidates for high efficiency motor replacement. Upgrading aging pumps with smaller and more accurately sized pumps significantly reduces operating cost. Correcting even short runs of undersized piping can also mean thousands of dollars a year in energy savings.
Compressed Air – Eliminate as many compressed air leaks as possible. The U.S. Department of Energy states that a single ¾” leak on a 100 psig compressed air system will cost the owner more than $7,000/year. Also consider replacing air powered equipment with equipment powered by electricity. An air powered hoist, for example, uses 5 hp for every 1 hp that would be used by an equivalent electrical hoist. Nearly 90% of the compressed air energy is waste heat. Consider capturing this energy for space heating.
Economizers - Take advantage of ambient air conditions by saving energy with airside and waterside economizers. For instance, many chilled water systems are forced to run to serve very small loads when they are oversized to begin with. Adding a waterside economizer allows the cooling tower to handle the load without the chiller. This saves significant operating cost, protects and increases the life of the chiller. Finally, make sure your air handling systems have comparative enthalpy economizers.
Air Conditioning Equipment – Upgrade aging systems with newer systems that include today's cost effective energy saving options such as, programmable thermostats, occupancy sensors, demand control ventilation (CO2 sensors), heat pumps, variable refrigerant flow systems and/or higher SEER ratings. Keep existing coils clean, change filters and have the refrigerant levels checked. Also have the economizers checked to make sure they are still operating.
Capacitors – Consider evaluating your power factor if you have old lighting, arc welders, induction heating equipment, lifting magnets, dry pack transformers, many motors or large motors. Low power factors may be costing you money. Most motors actually operate at part load most of the time and to make matters worse, power factor decreases with a decrease in loading. Depending on how you are billed for power, properly installed capacitors will increase your power factor and reduce low power factor penalty charges on your electric bill.
Lighting – One of the easiest ways to save energy is by replacing old lighting technology. This can range from simply replacing lamps, all the way to automating the control of the entire lighting system. Additionally, replacing older fluorescent fixtures in an office area with new technology fluorescent fixtures can save up to 30-40% on energy usage with no other modifications.
For the entire life of a typical warehouse/industrial metal halide (High Bay) fixture it draws approximately 455 watts of power, while the lighting level from the lamp drops over 60%. What started out to be a well lit space slowly gets dimmer while consuming the same amount of power. Hawkeye Energy Solutions can provide a detailed plan for energy saving options including cost effective maintenance programs or a complete design for replacing metal halide high bay fixtures with more efficient fluorescent fixtures.
