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Application
Published in Benny Raphael, Construction and Building Automation, 2023
Cooling load is a measure of the amount of cooling that is transferred during a heat exchange process. The term cooling loaddemand is used to denote the amount of cooling that is required to be supplied to a room or zone that is air conditioned. The term cooling loadsupply denotes the actual cooling that is supplied by the system. If the cooling is supplied by a coil carrying chilled water, the cooling load is the amount of heat absorbed by the chilled water per unit time. Since cooling load is the unit of energy divided by time, it can be expressed in Watts or kilowatts. But it should be noted that the cooling load does not denote the amount of electrical power consumed by the chiller; it is the amount of heat that is exchanged per unit time. Refrigeration ton (RT) is another commonly used unit for cooling load. 1 RT is equal to 3.517 kW.
Lighting
Published in Stephen A. Roosa, Steve Doty, Wayne C. Turner, Energy Management Handbook, 2020
Eric A. Woodroof, Stan Walerczyk, Fred Hauber
When not shaded, windows and daylighting cause an increased solar heat gain and additional cooling load for HVAC systems. However, development of new glazing systems and high performance windows has allowed designers to use daylighting without severe heat gain penalties. With dynamic controls, most daylit spaces can now have lower cooling loads than non-daylit spaces with identical fenestration. Reductions in heat gain due to daylighting can lower perimeter zone cooling requirements by 10% or more [8]. Because there are several parameters, daylighting does not always reduce cooling loads every time it displaces electric light. As window size increases, the maximum necessary daylight may be exceeded, creating additional cooling loads.
Heating, Ventilating, and Air Conditioning
Published in Barney L. Capehart, William J. Kennedy, Wayne C. Turner, Guide to Energy Management, 2020
Barney L. Capehart, William J. Kennedy, Wayne C. Turner
In addition to inside heating caused by radiation of solar energy absorbed by inside materials, the sun heat combines with the outside temperatures to create heating due to conduction through the walls and the roof. Although writing and solving the heat conduction equations are beyond the scope of this text, several observations can be made that are relevant to energy management. First, the amount of heat gain or loss through a wall depends on the thermal conductance—or U value—of the wall. Adding insulation to walls or roofs can significantly reduce the unwanted heat gain or heat loss through a wall and can be very cost effective if the main component of the cooling load is from conduction rather than from inside sources. Thermal conductance, insulation, and the calculation of heat transfer through walls and roofs are discussed in detail in Chapter 11.
Optimizing daylight, energy and occupant comfort performance of classrooms with photovoltaic integrated vertical shading devices
Published in Architectural Engineering and Design Management, 2023
Esmatullah Noorzai, Parnian Bakmohammadi, Maedeh Andaji Garmaroudi
− Energy use intensity (): This work intends to reduce the annual building energy demand, which incorporates both thermal and electric lighting energy usage. From the thermal aspect, a heating or cooling load is the heat amount needed to be inserted to or detached from the space air mass to keep the room air temperature at the thermostat setpoint temperature. For thermal performance assessment, the indicators of heating energy use intensity () and cooling energy use intensity () are used, which are obtained by summing up the hourly heating loads and annual hourly cooling loads for a year, respectively (Futrell, Ozelkan, & Brentrup, 2015). Like and , the lighting energy use intensity () is calculable through Equation (7). In this article, one of the objective functions is minimizing the total annual energy use intensity (), the sum of all the mentioned energy metrics.
On the incremental investment in residential energy efficiency: a Saudi perspective
Published in Energy Sources, Part B: Economics, Planning, and Policy, 2021
The levels of thermal insulation, reduced infiltration, and/or how much heat is gained through the windows will affect the maximum cooling load [] that a household experiences throughout the year. This will, in turn, influence the number of air conditioners the household needs and their capacity, which is reflected in their cost. Therefore, the cost of new air conditioners is formulated as a function of the maximum cooling load in each energy efficiency and demand response case. Since the cooling load is expressed in units of power, and air-conditioning capacity is given in units of energy, is included to indicate the time increment used. The air-conditioning unit cost includes installation.
Optimization of energy consumption and daylight performance in residential building regarding windows design in hot and dry climate of Isfahan
Published in Science and Technology for the Built Environment, 2020
Window glazing plays a crucial role in energy performance and has a significant effect on the overall building energy consumption. Heat flow through a glazed window contributes to the heat gain caused by solar radiation, which eventually increases the cooling load (Ke, Yeh, and Jian 2013). In buildings, the net energy gain through windows depends on the thermal properties of the glazing material. Double-pane coated glass windows are used to reduce heat and energy losses. They are highly effective in lowering the building energy consumption by reducing the cooling load when compared to traditional double-glazed clear glass windows. However, colored glazing reduces the admittance of daylight, thereby hindering the chance of effective utilization of daylight integration with artificial lighting (Arsenault, Hébert, and Dubois 2012). Simulations were performed to study the energy and daylight performance of the residential building model with different types of glazing in hot and dry climatic conditions. Table 8 presents the most commonly used types of glazing (bronze, low-E, and electrochromic), and their performance was analyzed.