The following table provides a quick reference to the main considerations with some of the most efficient technologies. As for lighting, test facilities are a good idea; is working with manufacturers and distributors.
Getting the most from climate controls
Because the performance of a building can be significantly improved by the installation and use of all
Commercial HVAC Repair Morristown NJ control, it is essential to understand and use the controls properly. The starting point is to look carefully at what is actually transpiring in your building 24 hours a day, seven days a week.
What happens to all the equipment? Vacation? Weekend? During the seasons do not change their operations? It is important to understand where and how energy is used to identify where waste occurs and where improvements can be implemented. So, it is imperative to ask: "What I want to do these checks?"
Energy management (EMS) systems are designed to operate individual devices more efficiently and enable the integration of equipment, improving system performance. In a typical EMS, sensors for monitoring parameters such as water temperature and air pressure, humidity, flow, and power consumption. From these points of performance, runtime equipment and electrical and mechanical instructions are controlled.
Programming seven days allows the hour and day-to-day control of HVAC and lighting can pose for holiday and seasonal changes. As its name suggests, the lowering of the temperature allows the night cooling in summer and less heating in winter during unoccupied hours.
Optimal start / stop allows the entire system to look ahead several hours and, in comparison with current conditions, to make decisions about how to proceed; This allows the system to slowly ramp, avoiding peak demand or the runtime unnecessary morning.
Peak electrical demand can be controlled by sequencing of fans and pumps to start one at a time rather than all at once and pieces of HVAC equipment for cutting short periods (30 minutes), should that very little affects the temperature of the space. Savings reduce cooling costs by taking advantage of fresh air outside. Supply air temperature reset can avoid excessive heat and help reduce the cooling load.
An EMS can provide a wealth of information about the performance of the building, but someone needs to understand what they want to do EMS and then give you directions. Calibration, testing and balancing controls are the key to any system of well maintained air conditioning, but are particularly important to optimize control efforts.
Variable speed drives and motors with improved energy efficiency
Variable speed drives (VSD) are often recommended as an effective reliable and cost last day.
Variable speed drives are cost effective, where the equipment is large or part-load operation frequently. Savings of up to 70 percent can be achieved by installing variable speed drives on fan motors operating at partial load. They can be applied to the compressor or pump and motors are typically used in variable air volume (VAV). They are also cost effective for secondary water applications. The backward inclined and airfoil fans are the best candidates for VOD.
Settings-manager controlled by air vane inlet or outlet dampers energy waste at partial load variable. Using butterflies to reduce the flow for small loads pumping is also ineffective. The engine performance begins to drop precipitously when they are at least 75 percent of the total load; they can consume more than two times more power than the load requires. Work electronically and continuously variable speed to adjust the speed to match the engine load.
The energy required VOD is proportional to the cube of the speed (or flow), which is why this technology is so effective. If the speed is reduced by only 10 percent, versus 27 percent of energy consumption should result. A pilot study by the EPA found that the VSD VOD modernization achieved an annual energy saving of 52 per cent, saving the average demand of 27 percent and a simple return of 2.5 years.
Perform harmonic power factor, electrical load and torsional analysis before selecting an inverter. Although the problems of harmonic content and power are not common in VSD applications, drivers must generally be equipped with integrated harmonic filters (or three-phase AC line reactor) and capacitors for power factor correction internal (or a single capacitor on the main line variable speed power). In general, this equipment is not standard and must be specified.
Better design and improve the performance of high-efficiency motors, which use 3-8 percent less energy than conventional motors materials; units in a yield of 95 percent are available.
For maximum savings, the engine must also be well suited to its load, increasing the run time with maximum efficiency. The engines run better when running 75-100 percent of maximum load; engines regularly below 60 per cent of the nominal capacity are prime candidates for refurbishment. For engines with loads fluctuate, drivers should also be taken into account.
The smaller, more efficient engines are essential downsizing maneuver one part of the system; reducing the size of an engine of 75 horse power standard for a model of energy efficiency in 40 horses will result in energy savings of 15 percent.
Some engines are less efficient "sliding" standard engines, which makes the efficient to operate at slightly higher engine speeds; examining a larger pulley to compensate for the higher speed and maximize energy savings. The installation of a new or existing pulley set may also be an alternative to VSD when the cost is prohibitive VOD or the load has been reduced.
Best performance of the ventilation system
A common way to improve the efficiency of the air distribution system is VAV systems for converting the constant air volume (CAV). An authority on energy, E-Source, reports that "(VAV) flow requirements of typical air are only about 60 percent of the maximum rate of CAV."
Vavs meet the load requirements, by varying the air volume through a combination of pressure control and dampers, rather than by variation of air temperature. Under the air pressure, power and volume of the air conditioning fan is reduced, thereby increasing the energy efficiency. Of course, it is essential to maintain the quality of indoor air quality (IAQ) when changing the air handling systems.
To maximize savings, components such as inverters VAV, variable pitch blades, diffusers, mixers and VAV boxes should work correctly; zoning attention is also needed to ensure the optimization of VAV.
E-Source recommends reviewing procedures VAV following renovation:
• measures to reduce the full load and calculate the requirements for maximum flow and minimum air
• measuring the performance of the existing fan; examine the duct system for possible improvements,
• stage fans which are connected in parallel,
• commissioning of the full system,
• optimize the set point and static pressure reset control and implement
• optionally removing air vents back.
Energy efficiency and correctly sized motors are also recommended along with careful control strategies. The installation of an independent control for each fed heat diffuser can add more control systems VAV controllers for individual spaces instead of entire fields and eliminate the need to VAV boxes. This device also offers CAV VAV style capabilities.
Renovation costs and return VAV can vary considerably. Problems installing fan control air, power reduced distribution, location of pressure sensors and reliability in addition to the faulty design can affect the performance of the modernization of the VAV. Because VAV boxes are relatively expensive and are required for each area, which is often not profitable to partition the space areas. Caution Area designation - according to occupation, internal and solar gain strength - will maximize efficiency, increase comfort and reduce heat.
When reheating can not be eliminated, consider these measures to reduce: ensure the calibration of thermostats; increasing the temperature of the food during the air-cooling station; and monitoring throughout the year and perhaps heating using heat only during the winter months. When the heat is mainly used to control the humidity, a desiccant wheel or heat pipes can be considered.
Reduction of existing VAV ventilation systems is a relatively inexpensive way to save energy when the Commercial HVAC were reduced or when the air distribution system was oversized to begin. Ways to reduce the number of fans or airflow requirements are:
• Reduce the nominal value of static pressure to meet the actual temperature and airflow.
• Motors rightsize and update energy efficient models; install larger pulleys.
• Replace the existing pulley with a larger fan; which will reduce energy requirements by reducing the fan speed.
• Make sure the fan speed is the load. Reducing the fan speed by 20 percent reduces the power consumption by about 50 percent.
There are several ways to determine if the VAV ventilation systems are great. If the measure of an engine intensity is 25 percent less than its nominal power, is large. If the blades of the fan inlet or outlet registers are closed more than 20 percent is large. If the reading of the static pressure is lower than the setpoint of the static pressure in the entries dampers are open and open VAV 100 percent, on a hot summer day, the system is large. Again, remember to consider the requirements of QAI restructuring of units of air handling systems.
Chillers and thermal storage
Nobody wants to replace a good cooling only because of the phasing out of CFCs. But since updates efficiency by reducing the load has been made, it may actually be cost effective to replace a large chiller. This is especially true given the rising prices and tight supply of CFC refrigerants.
Oversized units 10 years or more are good candidates for replacement. A cooler high efficiency reduces energy costs throughout its life cycle; initial costs are reduced because the chiller replacement is smaller than the former. Based on the effectiveness and charge unit age, the power consumption of a high efficiency chiller can be.15 to.30 kW / ton at least reducing the energy consumption by about 85 percent, is combined with downsizing.
An alternative is rehabilitation chiller replacement to accommodate a new refrigerant and to coincide with reduced loads. This may involve the replacement of the orifice plate, the substitution of the wheel and possibly the replacement of the compressor, depending on the particular refrigerator.
This can cause the seal and replace the motor and rewinding. According to the condenser, and as the replacement is completed, the refrigerator may lose its efficiency and capacity. To determine whether the replacement or renewal is a better option, both in initial cost and life cycle.
Retubing condenser and evaporator yields considerable energy savings, but it makes sense, given its high cost, depends on the state of the cooling system. Water-cooled condensers are generally more efficient than air-cooled units. Because the condensation water flows into an open circuit, is susceptible to fouling. The accumulation of scale will inhibit the effectiveness of heat transfer; maintenance is needed to clean surfaces.
Absorption chillers are an alternative to models of centrifuges. Absorption chillers cost up to $ 150 per ton than the vapor compression chiller as centrifugal units, but can be profitable in areas of high electrical load demand of vapor or gas is available, depending on local structures of utility rates. Using a combination of both types of cooling reduces the costs associated with the request.
The thermal energy storage (SET) using conventional refrigeration equipment production water conditioning or ice (or occasionally another phase change material) during peak periods. Water is withdrawn from storage during the day or during peak hours and circulated through the cooling system.
TES systems can be incorporated into new and existing systems and can provide load leveling shift complete or partial load. TES help reduce operating costs and maintenance; In some cases, a lower coolant can be specified. Some systems provide for air temperatures and low water power, thus the need for flow of air and water can be cut off.
Improve the water toward the
Fill material, configuration and size affect the efficiency of cooling tower fan. Filling the cell (or film packet) increases efficiency in comparison with other types of filling. The oversizing of the tower to allow closer to room temperature wetbulb can improve their efficiency. Sizing generously tower and increase its share of the cooling load can make economic sense because the cost and consumption of starting energy of one ton of cooling tower is smaller than a refrigerator.
Under partial load conditions, the application of a VSD to the fan (or pump) will improve the efficiency of the tower. Systems with variable speed fans and more are most effective when each cell tower operating at reduced speed, as opposed to one or two cells at maximum speed.
As cooling towers contain large heat exchange surfaces, dirt - or mud buildup of scale - can be a problem. The effectiveness of battered systems can be improved with effective treatment of the water. Tours are available in high yield; the induced draft type are more popular and more effective than pulling forced towers. Performance may also be improved by increasing the cooling surface.
In traditional pumping systems, the volume flow is generally constant; a throttle valve reduces the flow in conditions of partial load, the efficiency of inhibition.
Install variable speed drives on secondary pumps in systems with variable speed pumps and motors rightsizing to meet load requirements and improved single loop systems to configurations of the primary circuit performance / secondary and can increase reliability of pumping systems. In updating chilled water pumps, it is important to answer the maximum and minimum flow through the radiator.
Other cooling options
Desiccant dehumidification are materials that can be integrated into air conditioning systems to reduce cooling loads and increase cooling efficiency, improving the quality of indoor air and comfort. Once found only in niche industrial applications, drying extends all commercial markets.
Desiccants sense when the cost of regenerating them is small compared to the cost to dehumidify below the dew point and may reduce the peak power demand and HVAC more than 50 percent in some cases.
Evaporative coolers are one of the cheapest and most efficient cooling means using up to 75 percent less than the energy of vapor compression systems. Although the initial cost is generally higher, the payback period for evaporative coolers vary between six months and five years. Although evaporative coolers are particularly prevalent in the arid West and Southwest, they can serve most Americans climates. AND-indicates that source in combination with evaporative cooling, the cooling of the desiccant may be removed by air-conditioning in many climates.
Hybrid systems that integrate evaporative cooling with conventional cooling technologies offer additional possibilities. To improve performance, whereas low air velocity; better fill material; biggest fan, pump and engine efficiency, including variable speed drives; best belts or direct drive; better housing; better controls; and sealing the channel. Proper maintenance is the key to energy efficiency.
Devices packaged air conditioners are typically found in buildings or construction zones where the cooling load is less than 75 tons. The performance of these units can significantly reduce the loading efficiency of the part. They are generally not as effective as cooling systems, but can be improved, and when replacing rightsized. Existing systems can be improved through greater efficiency compressors, condensers and evaporators largest and drives, the expectation of 10 to 12 years to life these technologies may mean that reforms are not deficient.
Heat pumps are among the most heating and cooling technologies for energy efficient available today. Operating budget, increased reliability and life expectancy improve their sustainability costs. They work best in temperate climates and adequate size is essential.
Multi-unit configurations may serve as fillers and provide a larger area; large mainframes, modernized with capacity of up to 1,000 horsepower or 750 kilowatts gaining popularity. Pumps air to air heat are the most common, due to the low initial cost; heat pumps supply from the ground are the most effective, but tend to have high initial costs.
boiler upgrades
Especially in cold climates, the optimum boiler performance - improved controls fuel and air over a range of load conditions and increased heat transfer surfaces - can contribute substantially to the energy savings. Small modular units arranged on systems to increase efficiency up to 85 percent, while small units to replace the most effective shooting open-loop combustion condensing systems up to 95 percent.
Boiler retrofits, combined with measures of improved maintenance can also increase efficiency - up to 90 percent. New burners, baffle inserts, combustion controls, controls on hot, saving time, heat recovery ventilation and condensate return conversions can increase opportunities for efficiency. Boiler "was" less can be a good option if the boiler is needed throughout the year, but reduced in warmer conditions capabilities. The was much smaller boiler is sized to reduced costs; the boiler is the primary stop.
HVAC upgrades can provide tremendous economic benefits, improve occupant comfort and system reliability, and reduce operating costs. But to maximize the benefits and minimize capital investment, measures to reduce the load, such as lighting retrofit, should precede the modernization of HVAC systems.
Julian is Arhire manager DtiCorp.com - DtiCorp.com carries more than 35,000 HVAC products, including industrial, commercial and residential parts and equipment from Honeywell, Johnson Contols, Robertshaw, Jandy, Grundfos, Armstrong and more.
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