Monitoring, Targeting & Reporting in Buildings
Monitoring and targeting (M&T) energy use is a critical component of an effective energy management program. M&T techniques provide energy managers and users with feedback on operating
practices, results of energy management projects and guidance on the level of energy use that is expected in a certain period.
Economizers for Air Conditioning Units
Individually packaged heating, ventilating and air-conditioning (HVAC) systems, usually placed on the roof and known as rooftop units (RTUs) , are widely used in small and medium-sized commercial and institutional buildings.
Premium Efficiency Motors
Electric motor systems consume large amounts of electrical energy and can provide an opportunity for significant energy savings.
Heat Recovery with Boiler Stack Economizers
A stack economizer is a water-to-air heat exchanger that is designed to use heat from hot boiler flue gases to preheat water. For many decades, economizers have been used on large utility steam boilers to preheat the feedwater using recovered stack heat.
The same principle can be applied to smaller hydronic heating boilers where there is a nearby demand for hot water. These installations have become more economical as energy prices have risen and smaller economizers with light but durable and efficient heat exchangers have been developed.
One of the simplest ways to conserve energy is to turn lighting systems off in unoccupied areas.
However, accomplishing this task can sometimes be a challenge. Building lighting can be controlled by many methods, from simple – local switches, occupancy sensors, photocells and time clocks – to more elaborate computerized lighting control systems which can be tied in to automatic building mechanical and security system controls.
This fact sheet discusses the various control types and their operation and application.
Heat Recovery from Kitchen Refrigeration
Commercial kitchens require walk-in refrigerators and freezers to store perishable food. Each unit is normally equipped with its own compressor/condenser package which is cooled to remove the heat generated by the vapour compression refrigeration cycle.
Typically, this heat is released into the environment. Where the equipment is water-cooled, that heat can be recaptured for useful purposes like domestic water heating.
Reducing Water Use by Installing a Closed-Loop Compressor Cooling System
Some water-cooled air compressors use domestic cold water to cool the air between compression stages, and sometimes after the final compression stage. In urban areas, using cold municipal water for cooling purposes in an open loop (in which water passes through only once) is costly and wasteful.
This type of cooling is common in many systems because it is simple to set up and cold water is readily available. However, installing a closed-loop fan-coil system can nearly eliminate domestic water usage during winter and shoulder seasons.
Choosing a High Efficiency Chiller System
In many commercial facilities that require air conditioning, chillers are a major energy user. Thus, it is important to select a chiller that costs as little as possible to operate for the specific application.
Use of Variable Frequency Drives for Fan and Pump Control
In the past 10 years, variable speed control for fans, pumps, chillers and HVAC systems has become an affordable way to save energy, thanks to advances in microelectronics and control
technology. Initially, utility companies introduced incentives to make it practical to switch from fixed speed and flow-throttling controls to variable frequency drives (VFDs).
Since then, more building designs have been specifying VFDs, and many building HVAC retrofits can become more cost-effective by replacing flow controls with VFDs at installed costs as low as $250 per kilowatt. Naturally, the process must be carefully studied to ensure that the application will be successful.
Use of Automatic Vent Dampers for New and Existing Boilers and Furnaces
Boiler and furnace efficiency is usually defined in terms of steady-state operation. Efficiency measurements are taken and reported after the appliance has been running for a few minutes and has reached operating temperature. However, when appliance standby and skin losses are taken into account, the long-term or seasonal efficiency is usually much lower.