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A Simple Introduction to Financing Energy Management Projects
Published in Eric A. Woodroof, Albert Thumann, How to Finance Energy Managment Projects, 2021
Suppose PizzaCo (the “host” facility) needs a new chilled water system for a specific process in its manufacturing plant. The installed cost of the new system is $2.5 million. The expected equipment life is 15 years, however the process will only be needed for 5 years, after which the chilled water system will be sold at an estimated market value of $1,200,000 (book value at year five = $669,375). The chilled water system should save PizzaCo about $1 million/year in energy savings. PizzaCo’s tax rate is 34%. The equipment’s annual maintenance and insurance cost is $50,000. PizzaCo’s MARR is 18%. Since at the end of year 5, PizzaCo expects to sell the asset for an amount greater than its book value, the additional revenues are called a “capital gain” (equals the market value – book value) and are taxed. If PizzaCo sells the asset for less than its book value, PizzaCo incurs a “capital loss.”
Lexicon
Published in Samuel C. Sugarman, HVAC Fundamentals, 2020
chiller: (Refrigeration) A chiller (aka water chiller or water cooler) is a machine that removes heat from a water using a vapor-compression (mechanical chiller) or absorption (absorption chiller) refrigeration cycle. The water may contain glycol and corrosion inhibitors. In air conditioning systems, chilled water is distributed to heat exchangers, or cooling coils, in air handling units. The cooling coils transfer sensible heat and latent heat from the air to the chilled water cooling and usually dehumidifying the air stream. The warmed water is returned to the chiller for cooling. Chilled water is used to cool and dehumidify air in mid- to large-size commercial, industrial, and institutional facilities. A typical chiller for air conditioning applications is rated between 15 to 1500 tons (180,000 to 18,000,000 British thermal units) in cooling capacity. See mechanical chiller.
Thermal Environment Design Strategies
Published in Chitrarekha Kabre, Synergistic Design of Sustainable Built Environments, 2020
Radiant systems can have embedded hydronic tubing or attached piping in ceilings, walls, or floors. Chilled water is circulated through the floor/ceiling embedded pipes between 15°C and 17°C temperatures for cooling applications and hot water between 20°C and 35°C for heating applications depending upon the load conditions. Chilled water is generated either through conventional electric chiller systems or low energy chilled water generation systems like absorption chillers and desiccant chillers. Hot water is generated either through conventional boilers or solar hot water systems. The hydronic radiant systems include the following designs (Figure 3.39): Structure integrated systems – tubing in the ceiling, walls or floors slab (Thermally active building system-TABS) as per the provisions of ISO standard 11855 (ISO 2012). Applications of TABS can be seen in Standford University Central Energy Facility (section 6.3.4) and Research Support Facility, NREL, Golden (section 6.5.4).Embedded surface systemPanel systems (ceiling-suspended, wall-mounted). Applications of panel systems can be seen in Edith Green - Wendell Wyatt (EGWW) Federal building, Portland (section 6.4.4).
Development of event-driven optimal control for central air-conditioning systems
Published in Journal of Building Performance Simulation, 2020
Jin Hou, Xiaowei Luo, Gongsheng Huang, Linfeng Zhang, Zhun (Jerry) Yu, Mahroo Eftekhari
The selected typical air-conditioning system is illustrated in Figure 6, which has three basic loops: the cooling water (CW), the chilled water (CHW), and the supply air (SA) loops. In the chilled water loop, the chiller is used to generate chilled water, which is delivered by a constant speed pump in the primary side and a variable speed (vs) pump in the secondary side. In the cooling water loop, a constant speed pump is used to cycle the cooling water, which dissipated heat to the ambient. In the supply air loop, the supply air is conditioned by an air-handling unit (AHU) and delivered to zones for cooling. During the operation, the CWS, CHWS, and the SA temperatures were under feedback control to track their preset set-points. The CWS, CHWS and SA temperatures were controlled by adjusting the cooling tower fan frequency, the flow rate of the refrigerant inside the chiller, and the flow rate of the chilled water through the AHU respectively.
Thermal Energy Storage Configurations for Small Modular Reactor Load Shedding
Published in Nuclear Technology, 2018
Konor Frick, Corey T. Misenheimer, J. Michael Doster, Stephen D. Terry, Shannon Bragg-Sitton
Chilled-water storage is often overlooked as an effective TES method. Chilled water is regularly used in large manufacturing facilities, college campuses, and district heating and cooling systems to satisfy cooling demands. Traditionally, electric chillers make chilled water via the vapor-compression cycle. The chilled water is pumped to air handlers throughout a facility to satisfy comfort cooling needs. During warmer months of the year, a large portion of a facility’s electricity demand is generated from associated heating ventilation and air-conditioning (HVAC) equipment. Because building cooling loads regularly peak during the early to late afternoon hours, the HVAC equipment is sized to accommodate these peak loads. At night or during early morning hours when cooling loads are low, excess chiller capacity exists. Moreover, these peak facility cooling loads often coincide with peak electricity demands, thereby putting further strain on utilities. In the form of chilled-water storage, TES is a way to combat peak cooling loads by shifting them from on-peak to off-peak hours.17
Calibrated simulation study for efficient sizing and operating strategies for the thermal storage integrated air conditioning system
Published in International Journal of Sustainable Energy, 2021
Rana Veer Pratap Singh, Jaivardhan Singh, Jyotirmay Mathur, Mahabir Bhandari
To accomplish the objectives of the study, an occupied zone, used as an office space, on the second floor of the Old Administrative Building at Malaviya National Institute of Technology (MNIT) Jaipur was selected. Cooling is supplied by a chilled water system comprising a chiller, chilled water storage tanks, and pumping devices to deliver chilled water to the coils and air to the occupied zone. The experiment was conducted, and measurements were performed to calibrate the simulation model. The methodology is shown in Figure 1 and described below.