Tag Archives: HVAC Controls

Energy Efficiency in Buildings – How VFD’s Save Energy

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Have you wondered why Pumps and Fans are such a great opportunity to save energy using variable speed drives? ABB can help you estimate your energy savings a…

Source: www.youtube.com

>”  Efficiencies of Motors and Drives

The full load efficiency of AC electric motors range from around 80% for the smallest motors to over 95% for motors over 100 HP. The efficiency of an electric motor drops significantly as the load is reduced below 40%. Good practice dictates that motors should be sized so that full load operation corresponds to 75% of the rated power of the motor. […]

The efficiency of an electric motor and drive system is the ratio of mechanical output power to electrical input power and is most often expressed as a percentage.

Motor System Efficiency =Output MechanicalInput Electrical x 100%

A VFD is very efficient. Typical efficiencies of 97% or more are available at full load. At reduced loads the efficiency drops. Typically, VFDs over 10 HP have over 90% efficiency for loads greater than 25% of full load. This is the operating range of interest for practical applications. […]

The system efficiency is lower than the product of motor efficiency and VFD efficiency because the motor efficiency varies with load and because of the effects of harmonics on the motor.

Unfortunately, it is nearly impossible to know what the motor/ drive system efficiency will be, but because the power input to a variable torque system drops so remarkably with speed, an estimate of the system efficiencies is really all that is needed.

When calculating the energy consumption of a motor drive system, estimated system efficiency in the range of 80-90 % can be used with motors ranging from 10 HP and larger and loads of 25% and greater.

In general, lower efficiency ranges correspond to small motor sizes and loads and higher efficiency ranges corresponds to larger motors and loads.

b. Comparison with Conventional Control Methods

Estimating Energy Savings

Fans and pumps are designed to be capable of meeting the maximum demand of the system in which they are installed.

However, quite often the actual demand could vary and be much less than the designed capacity. These conditions are accommodated by adding outlet dampers to fans or throttling valves to pumps.

These are effective and simple controls, but severely affect the efficiency of the system.

Using a VFD to control the fan or pump is a more efficient means of flow control than simple valves or inlet or outlet dampers. The power input to fans and pumps varies with the cube of the speed, so even seemingly small changes in speed can greatly impact the power required by the load. […]

In addition to major energy savings potential, a drive also offers built-in power factor correction, better process control and motor protection. […]”<*

* Extracted from:  http://www.nrcan.gc.ca/energy/products/reference/15385

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Energy Efficiency, Smart Buildings & Wireless Control Systems

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Energy efficient technology and services for the building sector will double by 2022, according to a new report …

Source: www.climatecontrolnews.com.au

>”[…] Since buildings account for a large portion of national energy consumption, most of the governments in the Asia Pacific region have taken steps to promote energy management and energy efficiency in both new construction and existing buildings. […]

“With about 40 per cent of the world’s building stock, Asia Pacific represents a major portion of global real estate,” he said.

“Growing concerns about air pollution in Chinese cities, in particular, is expected to further drive investment in energy efficiency technologies to reduce China’s demand for coal-based electricity.

“The market for energy efficient buildings is expected to double in the next eight years, reaching nearly $92 billion in annual revenue by 2022.”

The largest segment of the energy efficient buildings market in Asia Pacific today is advanced lighting […]

“The commercial buildings sector in the region will experience a significant increase in the adoption of these products in the coming years,” Bloom said. Entitled“Energy Efficient Buildings: Asia Pacific”, the report examines the trends for energy efficient building technology and services in the Asia Pacific region.

It covers three main areas of technology – HVAC, energy efficient lighting, and commercial building automation – as well as the energy service company (ESCO) sector.

The convergence of building automation, information technology, and wireless communications is another area of growth identified by Navigant Research.

A separate report examines the state of the global wireless building controls industry, including global market forecasts for wireless node unit shipments and revenue through 2023.

Wireless controls can be used to link devices found in a variety of building systems, including heating, ventilating, and air conditioning (HVAC), lighting, fire and life safety, and security and access.

In addition, they often provide networked control in buildings or areas where wired controls are simply too challenging or expensive to install.

Worldwide revenue from wireless control systems for smart buildings is expected to grow from $97 million annually in 2014 to $434 million in 2023.  […]

While the adoption and deployment of wireless systems based on standard technologies and protocols, such as Wi-Fi, Zigbee, and EnOcean, are increasing, most wireless devices and control networks used today utilize proprietary, vendor-specific wireless communications technology.

That is likely to change as the demand for interoperability grows, according to the “Wireless Control Systems for Smart Buildings” report. “<

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Advanced Controls Devices for HVAC in Buildings shows growth

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Worldwide revenue from advanced HVAC controls is expected to grow from $7 billion annually in 2014 to $11.7 billion in 2023, according to a new report

Source: www.businesswire.com

BOULDER, Colo.–(BUSINESS WIRE)–Heating, ventilation, and air conditioning (HVAC) in commercial buildings typically accounts for roughly 40% of total building energy consumption. While advancements have been made in the efficiency of HVAC equipment, the actual energy consumption of HVAC equipment depends largely on their operation – which can be made much more efficient and less energy-intensive through the application of advanced HVAC controls. […]

“The drive to reduce energy use in commercial buildings has put a spotlight on improving the efficiency of HVAC systems, and HVAC controls retrofits offer a compelling value proposition through reduced energy consumption in existing buildings.”

[…]

New building certification and benchmarking regulations are driving faster retrofits of controls in existing buildings, according to the report, and changing how automation is designed into new buildings. The wider adoption of open standards for controls functions (such as BACnet), and of communications based on the Internet Protocol (IP) suite and Ethernet connectivity, is expected to help bring advanced HVAC technology to a wider market.

[…]

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