scholarly journals Impact of Implementing a Dedicated Outdoor Air System in Parallel with a Multi-Zone Variable-Air Volume System on Energy Consumption, Thermal Comfort, and Life Cycle Cost

2019 ◽  
Author(s):  
Khaled Alghamdi
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Life Cycle Cost ◽  
Outdoor Air ◽  
Variable Air Volume ◽  
Air Volume ◽  
Air System

Analysis of Running Energy Consumption of Fresh Air Cooling Systems

Solar Energy ◽  
2005 ◽  
Author(s):  
Jianing Zhao ◽  
Jun Guo ◽  
Weimeng Sun
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Cooling System ◽  
Air Cooling ◽  
Total Energy Consumption ◽  
Cooling Systems ◽  
Variable Air Volume ◽  
Air Volume ◽  
Air System ◽  
Different Seasons

Utilization of renewable energy becomes more and more attractive and crucial for sustainable buildings. A cooling system, using outdoor fresh air and combining with the conventional all-air system or running along during different seasons, is discussed in this study. Running energy consumption of this system is analyzed by a mathematical model using the Genetic Algorithm (GA) combined with the traditional Lagrange method. To evaluate and apply this new system, energy consumption of the chiller unit, water and air sub-systems, as well as the total energy consumption of such a system is compared with that of the conventional all-air system. Consequently, the total energy consumption is selected as the criterion of energy efficiency. The results show that the cooling system bears considerably energy efficient, and that it reduces energy consumption at least 14% and 12%, compared with the constant air volume and variable air volume system, respectively.

Energy conservation potential of an indirect and direct evaporative cooling assisted 100% outdoor air system

2011 ◽  
Vol 32 (4) ◽  
pp. 345-360 ◽  
Author(s):  
MH Kim ◽  
JH Kim ◽  
OH Kwon ◽  
AS Choi ◽  
JW Jeong
Keyword(s):  
Energy Savings ◽  
Evaporative Cooling ◽  
Outdoor Air ◽  
Variable Air Volume ◽  
Energy Saving Potential ◽  
Air Volume ◽  
Direct Evaporative Cooling ◽  
Air System ◽  
Evaporative Cooler ◽  
Cooling Coil

This study aims to present the fundamentals in which operation of a 100% outdoor air system integrates with indirect and direct evaporative cooling systems and to estimate its energy saving potential. The simulation of the proposed system is performed using a commercial equation solver program, and the annual operation energy saving potential with respect to a conventional variable air volume system is determined. This paper shows that significant operation energy savings (i.e. 21–51% less energy consumption) is possible principally by the pre-conditioning of supply air due to the waste heat recovery using the indirect evaporative cooler and the sensible heat exchanger units. By components, the proposed system shows a 16–25% less annual cooling coil load and an 80–87% reduced annual heating coil load with respect to the conventional variable air volume system, while there is no fan energy savings expected. Practical applications: This paper provides practical insight on how the evaporative cooling based 100% outdoor air system operates and how each essential component, such as the indirect evaporative cooler, cooling coil, direct evaporative cooler, heating coil and sensible heat exchanger should be controlled during the seasons for realising energy conservation benefits. The sequence of operation presented in this paper can be implemented to actual control logic.

scholarly journals Energy-saving potential of dedicated outdoor-air system assisted by vacuum-based membrane dehumidifier

2019 ◽  
Vol 111 ◽  
pp. 01087 ◽  
Author(s):  
Seong-Yong Cheon ◽  
Soo-Yeol Yoon ◽  
Su Liu ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Saving ◽  
Primary Objective ◽  
Dew Point ◽  
Outdoor Air ◽  
Variable Air Volume ◽  
Energy Saving Potential ◽  
Air Volume ◽  
Air Supply ◽  
Radiant Cooling ◽  
Air System

The proposed research presents a dedicated outdoor-air system (DOAS) integrated with a vacuumbased membrane dehumidifier (VMD). The primary objective of this study was to evaluate the energy-saving potential of the proposed VMD–DOAS combination. VMD–DOAS comprised a membrane-energy exchanger (MEE), dew-point indirect evaporative cooler (DP-IEC), and VMD. VMD possessed a characteristic by virtue of which the dehumidification process was isothermal; i.e., no temperature change was observed during the VMD process. While VMD served to control the dry-air supply, the required target temperature (i.e., 17 °C) was maintained via DP-IEC operation. The remaining sensible heat of the conditioned zone was controlled by the ceiling radiant cooling panel (CRCP). The load of the conditioned zone was driven by TRANSYS 18, and an engineering equation solver (EES) was used for evaluating the energy-saving potential of the proposed system with CRCP by comparing it against the variable-air-volume (VAV) system. Results of this study demonstrated that the proposed DOAS with CRCP consumed 37% less operating energy compared to the VAV system. This observed energy-saving potential of the proposed system was driven by reducing the dehumidification load and subsequent energy recovery by MEE.

scholarly journals The Analysis for Energy Consumption of Marine Air Conditioning System Based on VAV and VWV

2018 ◽  
Vol 38 ◽  
pp. 04012
Author(s):  
Sai Feng Xu ◽  
Xing Lin Yang ◽  
Zou Ying Le
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Water Volume ◽  
Pump System ◽  
Air Conditioning System ◽  
Variable Air Volume ◽  
Air Volume ◽  
Marine Air ◽  
Variable Water

For ocean-going vessels sailing in different areas on the sea, the change of external environment factors will cause frequent changes in load, traditional ship air-conditioning system is usually designed with a fixed cooling capacity, this design method causes serious waste of resources. A new type of sea-based air conditioning system is proposed in this paper, which uses the sea-based source heat pump system, combined with variable air volume, variable water technology. The multifunctional cabins’ dynamic loads for a ship navigating in a typical Eurasian route were calculated based on Simulink. The model can predict changes in full voyage load. Based on the simulation model, the effects of variable air volume and variable water volume on the energy consumption of the air-conditioning system are analyzed. The results show that: When the VAV is coupled with the VWV, the energy saving rate is 23.2%. Therefore, the application of variable air volume and variable water technology to marine air conditioning systems can achieve economical and energy saving advantages.

scholarly journals Least Cost Analysis of Energy Efficiency Upgrades for Ontario Using Trnsys

2021 ◽  
Author(s):  
Amir Fereidouni Kondri
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Cost Analysis ◽  
Energy Efficient ◽  
Life Cycle Cost ◽  
Net Present Value ◽  
Hot Water ◽  
Life Cycle Costs ◽  
Residential Housing ◽  
Domestic Hot Water

This report presents the methodology for determining least cost energy efficient upgrade solutions in new residential housing using brute force sequential search (BFSS) method for integration into the reference house to reduce energy consumption while minimizing the net present value (NPV) of life cycle costs. The results showed that, based on the life cycle cost analysis of 30 years, the optimal upgrades resulted in the average of 19.25% (case 1), 31% (case 2a), and 21% (case 2b) reduction in annual energy consumption. Economic conditions affect the sequencing of the upgrades. In this respect the preferred upgrades to be performed in order are; domestic hot water heating, above grade wall insulation, cooling systems, ceiling insulation, floor insulation, heat recovery ventilator, basement slab insulation and below grade wall insulation. When the gas commodity pricing becomes high, the more energy efficient upgrades for domestic hot water (DHW) get selected at a cost premium.

Energy and Economic Analysis for Greenhouse Envelope Design

2018 ◽  
Vol 61 (6) ◽  
pp. 1795-1810
Author(s):  
James Bambara ◽  
Andreas K. Athienitis
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Economic Analysis ◽  
Life Cycle Cost ◽  
Energy Use ◽  
Electricity Consumption ◽  
Base Case ◽  
Local Climate ◽  
The North ◽  
North Wall

Abstract. The energy consumption of a building is significantly impacted by its envelope design, particularly for greenhouses where coverings typically provide high heat and daylight transmission. Energy and life cycle cost (LCC) analysis were used to identify the most cost-effective cladding design for a greenhouse located in Ottawa, Ontario, Canada (45.4° N) that employs supplemental lighting. The base case envelope design uses single glazing, whereas the two alternative designs consist of replacing the glass with twin-wall polycarbonate and adding foil-faced rigid insulation (permanent or movable) on the interior surface of the glass. All the alternative envelope designs increased electricity consumption for lighting and decreased heating energy use except when permanent or movable insulation was applied to the north wall and in the case of permanent insulation on the north wall plus polycarbonate on the east wall. This demonstrates how the use of reflective opaque insulation on the north wall can be beneficial for redirecting light onto the crops to achieve simultaneous reductions in electricity and heating energy costs. A maximum reduction in LCC of 5.5% (net savings of approximately $130,000) was achieved when permanent insulation was applied to the north and east walls plus polycarbonate on the west wall. This alternative envelope design increased electricity consumption for horticultural lighting by 4.3%, reduced heating energy use by 15.6%, and caused greenhouse gas emissions related to energy consumption to decrease by 14.7%. This analysis demonstrates how energy and economic analysis can be employed to determine the most suitable envelope design based on local climate and economic conditions. Keywords: Artificial lighting, Consistent daily light integral, Energy modeling, Envelope design, Greenhouse, Life cycle cost analysis, Light emitting diode, Local agriculture.

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