Operation Of A Heating Ventilation And Air Conditioning Construction Essay

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The federal government relies on technological advancements in regulating the amount of energy used in commercial buildings. As a result, facility owners are being urged to maintain their systems approach and decrease the amount of energy used during unoccupied hours. HVAC systems that operate during unoccupied hours can produce undesirable room temperatures and become considerably costly to facility owners. These same facility owners are being offered excellent solutions to having more control over their heating and cooling systems due to the advancements in smart building technology. The commercial construction market predominantly utilizes green building technology and LEED concepts in retrofitting HVAC systems in commercial buildings. Precise control of HVAC systems maintains a comfortable indoor climate for the buildings occupants, optimizes the indoor conditions for operating equipment or stored inventory, and does these functions with minimum energy use during all times of the year (NJATC, 2008, p. 106). Retrofitting existing HVAC systems to improve upon all of these things has proven to be a considerable investment for owners of commercial buildings throughout the United States.

Occupancy control can be integrated with building HVAC systems, turning off ventilation air, heating and cooling, in space with no occupants (Richard Lay, 2010). Standard thermostat controls in existing buildings are considered ancient compared to today's system upgrades. With inadequate control systems, it is common for facility managers to operate HVAC systems to minimize complaints of occupants. Due to the inability to control specific zones throughout the building, portions of the building may become greatly overheated in order to maintain comfortable conditions in other areas. This practice has proven to be wasteful of both, energy and money. Therefore, an HVAC control system is utilized in buildings to counter issues with comfort, temperature, humidity, circulation, filtration, and ventilation. The two primary functions of any HVAC control device are to ensure equipment safety and maintain one or more of the following building conditions listed above.

As previously stated, unconventional operation of existing HVAC systems can cause excessive energy consumption, tenant complaints, poor indoor air quality, and eventually environmental damage. Most of these HVAC systems can be retrofitted to increase dependability, decrease the energy source, and optimize performance to meet or exceed today's environmental standards; however, the first two concerns are the most common reasons for HVAC system retrofits, but environmental concerns should be considered as a part of any change (Haviland, HVAC Retrofit Concerns, p. 1). HVAC control devices include sensors to measure the current climate conditions and the presence of occupants within a zone, devices to control the temperature and humidity of supply air, and devices to control the distribution of air, water, or steam throughout the HVAC system (NJATC, 2008, p. 122). These smart building components use a combination of intelligent automation, modern communications, and several other technology solutions to operate, monitor, and maintain a building and its energy use in the most efficient and cost-effective manner possible. The ultimate goal is to provide facilities managers the ability to base operational decisions on real-time performance data and uncover hidden costs, and opportunities to save money, through comprehensive facilities management (ARC Advisory Group, 2009, p. 1).

Control Systems utilize a digital device known as a Direct Digital Control (DDC) to perform smart building integration. The DDC is capable of confirming that the HVAC systems are operating within control system instructions. An HVAC system can also be configured using remote monitoring and can detect systematic problems during operation. The DDC system can provide information about the building and the system, allowing the maintenance staff to check on conditions without going all over the building meaning if there is a complaint, the temperature in the area and the operation of the equipment can be checked immediately (Haviland, p. 1). Still, constant monitoring of the equipment is important to identify potential issues before they affect tenants. Control features can also ensure that the system was installed or serviced correctly, further reducing maintenance costs. For example, air handling units (AHU's) in existing facilities manage four types of air including return air, outside air, exhaust air, and supply air. By controlling the fans, dampers, coils, and other devices within an air-handling unit, the unit can be used to heat, cool, humidify, dehumidify, or simply ventilate a building space to fit the desired needs of the occupants inside (NJATC, 2008, p. 141).

Prior to any retrofit work in existing buildings, facility managers should ensure that the existing system is operating at its full potential. All of the components in the system, as well as the controls, must perform their particular tasks. Without ensuring that the system is operating at full potential, changes might be made to the existing system that may not be needed or the retrofitted system may not achieve its projected performance results. Testing and balancing of the system should be included as part of any major retrofit project and facility managers should allow time in the engineer's contract to review and participate in the start-up of the changes (Haviland, HVAC Retrofit Concerns, p. 3). Performing these duties will help make certain that the system will operate as planned. As stated several times throughout this paper, HVAC retrofits are generally undertaken to boost a system's cost or energy efficiency and all retrofits should take both of these factors, as well as environmental concerns, into account when upgrading existing systems (Haviland, HVAC Retrofit Concerns, p. 3). Not doing so would be unacceptable and may be detrimental to the lifecycle cost of operating the HVAC system post-retrofit.

One aspect of HVAC control systems that was not always considered in the past is that energy efficiency, lower environmental impact, and improved employee productivity all add up to a lower total cost of ownership and more attractive bottom line (Gillepsie, 2010, p. 1). These intelligent controls allow facility managers to sit back as the system monitors and optimizes energy use, while sending out alarms and notices that can decrease downtime. Volatile energy costs and tightening government regulations helped open businesses eyes to the economic, social, and environmental benefits of optimizing energy consumption (ARC Advisory Group, 2009, p. 1). The systems that involve lowering the total cost of ownership over the entire lifecycle of a building are being utilized more often today due to the current economic and environmental impacts they provide. A graphical representation of the significant savings in electrical use by full integration of a retrofitted HVAC system using controls over an existing standard system is shown in figures 1 and 2 (See Appendix A). The results of distributing control are new benefits for customers through precise control, technical capabilities, remote communication and energy cost reductions (McGowan, 1995, p. 27). Installing high-performance HVAC equipment in existing facilities can lead to considerable savings in energy cost. Typically, a 30% reduction in annual energy costs can be achieved with a simple payback period of about three to five years and if the payback is extended to seven years, the savings can be about 40% (Graham, 2009).

Along with the idea that direct oversight in existing commercial buildings is quickly dissipating and the fact that building owners are continually preparing for renovations, they are taking into consideration more than just the cost of buying, installing, and maintaining individual elements. While control systems can indeed be complex, they are now an essential component of modern buildings and will continue to evolve; therefore, designers and owners should make every effort to understand the technology so they can operate their buildings at their best efficiency (Richard Lay, 2010). Intelligent control systems can monitor and optimize energy consumption, quickly send out alarms and notifications that can prevent downtime, provide reports of systems that may be in override mode, and record historical data to monitor trends in energy consumption (Report shows HVAC control market ripe for innovation , 2009). However, a common interest in the Building Automation field revolves around the realization that no element within a system can work single handily toward achieving optimum performance in a facility. HVAC control-system upgrades have proven to be the most popular retrofits in existing commercial buildings today. The improved technology of currently manufactured systems provides improved control of the system, which can increase tenant comfort as well as save energy and most of these systems also can provide the information required to bill tenants for after-hours energy consumption (Haviland, p. 3).

As stated before, the control systems within a smart building work together in order to regulate the comfort, temperature, humidity, circulation, filtration, and ventilation in an existing facility meaning that all systems must be in sync with one another to coexist in a controlled indoor environment. Proper performance and energy-efficient operation of HVAC systems can only be ensured through a successful Operation & Maintenance (O&M) program (Graham, 2009). Therefore, it is important for facility managers to understand that separate components of the HVAC system have different maintenance requirements essential for achieving optimum performance. Another major concern with traditional automation systems is that they are typically limited to a single building system or equipment manufacturer, which severely limits the potential ability of automation to involve multiple systems seamlessly and reliably (NJATC, 2008, p. 352). It is projected that about 75 percent of the opportunities in the HVAC controls market come from existing buildings that need to be updated or retrofitted. This trend will accelerate in the next few years as government-funded stimulus money is used to increase the energy efficiency of existing buildings and the growing concerns in the US commercial real estate market may lead to a decrease in new building construction and an increase of owners of existing buildings who make retrofit investments to qualify for LEED points (Arc Advisory Group, 2009).

Finally, although building automation involving HVAC control systems has seen significant improvements throughout the first decade of the 21st Century, it is said that the market has not yet seen the best of its use. According to Joseph Gillepsie, the principal author of ARC's HVAC Control Systems Worldwide Outlook,

"Fundamental changes taking place in the commercial construction market, such as the need for enterprise visibility, integration of HVAC systems with other building automation systems, increasing use of analytics in HVAC control, energy management initiatives, and the impact of Web-enabled systems and cloud computing make this dynamic market ripe for innovation" (Report shows HVAC control market ripe for innovation , 2009).

As long as we see advancements in technology, we will see new innovations in HVAC control devices attempting to perfect this industry of opportunity. By continuing to provide a non-invasive, less costly, and less time-consuming solution, suppliers will be able to leverage the boom in the retrofit sector of the HVAC controls market (Arc Advisory Group, 2009). The decision to install new HVAC or climate control systems will continue to rely on the growing concern for occupant health and comfort, the need to make existing buildings profitable in today's economy, and the desire to properly control the indoor temperature for particular building uses.