PV Operated HVAC for Southwest States

Solar Energy ◽  
2006 ◽  
Author(s):  
Joseph McCabe
Keyword(s):  
Direct Current ◽  
Air Conditioning ◽  
High Efficiency ◽  
Air Conditioner ◽  
Hvac System ◽  
Energy Usage ◽  
Pv System ◽  
Two Stage ◽  
System A ◽  
Evaporative Cooler

This report analyzes energy usage and associated utility capacity requirements for compressor based air-conditioning compared to evaporative cooling supplied by electricity from photovoltaics (PV). Two novel scenarios are presented, two stage evaporative coolers with grid tied PV, and two stage evaporated coolers supplied with direct current (DC) electricity from PV. The two scenarios are complimentary; where a grid tied system can tap DC for air-conditioning purposes (see Figure 1). 8% PV system gains can be achieved by eliminating the inverter for powering such a DC heating, ventilating and air-conditioning (HVAC) system. A PV system directly coupled to high efficiency evaporative cooler can remove the air-conditioner peak demand from a utilities load profile. Typical cities energy comparisons are presented. Incentive and public goods programs are not necessarily designed for this optimized, direct utilization of DC approach.

THE PERFORMANCE OF CONDENSER UNDER DIFFERENT VEHICLE SPEEDS

2013 ◽  
Vol 21 (02) ◽  
pp. 1350013 ◽  
Author(s):  
CHIH-CHIU SHEN ◽  
JAU-HUAI LU
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Air Conditioning ◽  
High Efficiency ◽  
Cooling Capacity ◽  
Vehicle Speed ◽  
Air Conditioner ◽  
Electric Motors ◽  
No Emission ◽  
Air Conditioning System

Due to the concern in energy shortage and environmental protection, electric vehicle is considered to be a substitute for the conventional gasoline-powered vehicles due to its characteristics of high efficiency and no emission. However, the load of air conditioning causes a serious problem for electric vehicles, especially in tropical and subtropical areas. The compressor of conventional air conditioning system is driven by engine and its speed is thus coupled to vehicle speed. In electric vehicles, the compressor is driven by electric motors and compressor speed could be decoupled to vehicle speed. This mechanism provides an opportunity to improve the energy efficiency of electric vehicle since the operation of air conditioning system may be independent of vehicle speed. The purpose of this paper is to find out the electric fan operation model as vehicle speed is varied. This paper was to establish a theoretical model for the condenser of automotive air conditioner and to conduct simulation to evaluate the effect of vehicle speed on the cooling capacity and sub-cooling of condenser. Results of simulation demonstrated that vehicle with 6 km h-1 speed has the 5°C of sub-cooling at 0.0266 kg s-1 of refrigerant flow rate and the cooling capacity was 4.93 kW. In this study, an increase of 16.6% in cooling capacity can be reached as the speed of vehicle was raised from 6 to 110 km h-1 and can promote the sub-cooling to 19.5°C. It was also found that the cooling capacity of air conditioner is extremely sensitive to vehicle speed while the vehicle is running at low speed. Furthermore, increases in the vehicle speed resulted in reduction of the length of superheat region from 17.5 to 8.5 cm. Finally, a correlation among these variables and the simulated cooling capacity was obtained in this study, enabling the relevant researchers to evaluate automotive air conditioner performance under different vehicle speeds more easily.

scholarly journals Application of heat pump combined two-stage desiccant wheel fresh air system of residential buildings in mixed climate zone

2019 ◽  
Vol 111 ◽  
pp. 01009
Author(s):  
Shaochen Tian ◽  
Xing Su ◽  
Xu Zhang
Keyword(s):  
Heat Pump ◽  
Air Conditioning ◽  
Residential Buildings ◽  
Dew Point ◽  
Air Conditioner ◽  
Operation Performance ◽  
Two Stage ◽  
Climate Zone ◽  
Desiccant Wheel ◽  
Air System

The building requires dehumidification for a long period of time in mixed climate zone of China. As a conventional method for dehumidification, vapor compression systems remove the water vapor by cooling the process air below dew point. This system consumes a lot of energy for reheating the air to meet the requirement of supply air temperature. A heat pump combined with two-stage desiccant wheel (TSDW&HP) is proposed as an air conditioning and dehumidification system in this study. The operation performance of proposed system applied in a hypothetical residence with 3 residents was investigated and simulated by using TRNSYS software. The operation modes of the system are discussed for different scenarios of season and outdoor air humidity ratio. In dehumidification season, fresh air deals with all of the latent load. In air conditioning season, fresh air deals with all of the moisture load with part of the cooling load. When evaporation temperature of HP is reduced and more moisture load is processed by evaporator in air conditioning season, there is a balance point between the performance of DWs and heat pump. The energy consumption of TSDW&HP fresh air system was compared with a conventional fresh air conditioner during dehumidification season and air conditioning season. It was found that the energy-saving potential of this system is 27.3% compared with conventional air conditioner.

scholarly journals Comparative Analysis of Energy Consumption, Indoor Thermal–Hygrometric Conditions, and Air Quality for HVAC, LDAC, and RDAC Systems Used in Operating Rooms

2020 ◽  
Vol 10 (11) ◽  
pp. 3721
Author(s):  
Tsung-Yi Chien ◽  
Ching-Chieh Liang ◽  
Feng-Jen Wu ◽  
Chi-Tsung Chen ◽  
Ting-Hsin Pan ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Air Quality ◽  
Air Conditioning ◽  
Operating Rooms ◽  
Conventional Heating ◽  
Hvac System ◽  
Total Energy Consumption ◽  
System A ◽  
Air Conditioning Systems ◽  
Daily Total

As controlling temperature and humidity is crucial for maintaining comfort and preventing microbial growth, operating rooms (ORs) are the most energy-intensive areas in hospitals. We aimed to evaluate the energy consumption of three dehumidification air conditioning systems used in ORs and their corresponding air quality for ORs at rest. This study selected three ORs using a conventional heating, ventilation, and air conditioning (HVAC) system; a liquid desiccant air conditioning (LDAC) system; and a rotary desiccant air conditioning (RDAC) system, respectively. The indoor thermal–hygrometric conditions, air quality, and energy consumption of the ORs were monitored in this study. The median levels of relative humidity (RH) were 66.7% in the OR using the conventional HVAC system, 60.8% in the OR using the LDAC system, and 60.5% in the OR using the RDAC system. The median daily total energy consumption of the RDAC system (10.1 kWh/m2) and LDAC system (11.8 kWh/m2) were 28.12% and 16.54% lower, respectively, than that of the conventional HVAC system (14.1 kWh/m2). The PM≥0.5 levels and airborne bacterial concentrations in the ORs met the ISO 14644-1 Class 7 standard and China’s GB50333-2013 standard, respectively. The RDAC system was clearly superior to the LDAC and conventional HVAC systems in terms of energy consumption.

Analysis of Ejector in Central Air Conditioner Combined with Solar Ejector Refrigeration System

2013 ◽  
Vol 860-863 ◽  
pp. 733-736
Author(s):  
Hui Lan Huang ◽  
Gang Li ◽  
Xiang Chen ◽  
Zhong Yi Su
Keyword(s):  
Air Conditioning ◽  
Function Method ◽  
Air Conditioner ◽  
System Efficiency ◽  
Refrigeration System ◽  
System A ◽  
Central Air Conditioning ◽  
The Common ◽  
Main Component ◽  
Solar Refrigeration

Comparing with the common jet refrigeration system, a central air conditioner combined with solar ejector refrigeration system was proposed. The system characteristic was presented. It can improve the coefficient of the single solar system and solve operation problem for day-and-night, and can reduce the energy consumption of central air conditioner. A reasonable ejector to match with the central air conditioning is a main component in the system. The ejector in the solar refrigeration system is preliminary analyzed by the pneumatic function method. It will provide the important reference to improving the conditioner performance and system efficiency on air conditioning energy saving.

Theoretical and experimental simulation of roof-top bus multiple-circuit air-conditioning system performance

2007 ◽  
Vol 221 (12) ◽  
pp. 1665-1677
Author(s):  
M Khamis Mansour ◽  
M N Musa ◽  
M N W Hassan ◽  
H Abdullah
Keyword(s):  
Experimental Data ◽  
Computer Model ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Experimental Simulation ◽  
Cooling Load ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
System A ◽  
Cooling Loads

Many air-conditioning (AC) systems are designed to operate at maximum cooling capacity regardless of the variation in the daily cooling load. At low loads, the conditions can be uncomfortably cold and the overcooling is an unnecessary waste of energy. To address these two issues, a multiple refrigeration circuit concept is proposed and applied to a roof-top bus AC system. A two-circuit model is proposed for a standard bus size in which each circuit has two evaporators of equal sizes arranged in parallel and installed on each passenger row, respectively. This means that each passenger row is served by two different evaporators sharing a common heat exchanger box. Depending on the cooling load, this concept allows one or both circuits (compressor motors) to be switched on and during either modes, it also allows one or more sets of evaporator blowers to be switched on. A steady-state computer model has been developed to simulate the performance of the proposed two-circuit AC system. A two-circuit air conditioner is also designed to form a roof-top bus AC system, fabricated, and installed on to an experimental rig. The experimental data are used to validate the computer model. The validation is on the system thermal performance and on the evaporator air outlet conditions (dry bulb temperature and relative humidity) at different modes of system operation, either at full or partial cooling loads. The simulated results gave satisfactory agreement with those obtained from the experimental work. Maximum absolute deviations are within the range of 19.3 per cent, although most of the simulated results are less than a 10 per cent range from the experimental ones, which validates the computer program. The paper describes the modelling work carried out and the results obtained are presented in comparison with the experimental data.

A Remote Intelligent Control System for Split Air Conditioning System

2013 ◽  
Vol 325-326 ◽  
pp. 1162-1165
Author(s):  
Jie Ming Ding ◽  
Zhen Zhong Li ◽  
Wei Bo Li ◽  
Pin He ◽  
Yang He
Keyword(s):  
Control System ◽  
Intelligent Control ◽  
Air Conditioning ◽  
High Efficiency ◽  
Control Unit ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Air Conditioners ◽  
Intelligent Control System ◽  
Intelligent Terminal

Combined wireless sensor network technology (WSN) and infrared control technology this paper designs an intelligent control system for split air conditioner (ACSS). The system adopts the SimpliciTI protocol and a highly integrated chipset, CC1110, as wireless sensing node, which it has high efficiency and lower power. The intelligent remote control unit of the system is capable of signal conversion, wireless communication as well as infrared control ability. In order to suit different air conditioners, the system establishes a control code library by learning a variety of air-conditioning infrared control signals. The control parameters optimized by the system server are transmitted to the intelligent terminal and then fires the infrared control signal to the air conditioner. Therefore, the system achieves the purpose of the remote intelligent controlling.

Thermal Comfort Conditions in Ships

2010 ◽  
Vol 26 (01) ◽  
pp. 60-65
Author(s):  
José A. Orosa ◽  
Guadalupe Iradi ◽  
Armando C. Oliveira
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Extreme Conditions ◽  
Indoor Environments ◽  
Hvac System ◽  
Control Room ◽  
Conditioning Procedure ◽  
System A ◽  
Engine Room ◽  
Dining Room

Ship indoor environments are related with comfort conditions and health risk problems. As a consequence, to obtain an adequate heating, ventilation, and air conditioning (HVAC) system, a redesign of the engine control room must be made. To answer this problem, an analysis of real thermal comfort conditions was carried out and a new air conditioning procedure is proposed. From the obtained results it can be concluded that comfort conditions in the bridge and dining room are close to neutral, while the most extreme conditions have been found in the engine room.

scholarly journals High-Efficiency HVAC System with Defog/Dehumidification Function for Electric Vehicles

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Tong-Bou Chang ◽  
Jer-Jia Sheu ◽  
Jhong-Wei Huang
Keyword(s):  
Electric Vehicles ◽  
Air Conditioning ◽  
High Efficiency ◽  
Test Chamber ◽  
Power Saving ◽  
Electric Heating ◽  
Heating System ◽  
Cold Weather ◽  
Hvac System ◽  
Vehicle Interior

Electric vehicles (EVs) generally use an electric heating system to provide heat. However, the heating system consumes a large amount of energy, and therefore reduces the mileage of the vehicle. The energy consumption can be reduced by replacing the electric heating system with a heat pump air conditioning system. Such systems achieve an effective heating of the vehicle interior, but do not provide a defog or dehumidification function. Consequently, the inside surface of the windshield tends to fog in cold weather; leading to poor driver visibility and an impaired road safety. Accordingly, the present study proposes a novel high-efficiency heating, ventilation and air conditioning (HVAC) system with both heating and defog/dehumidification functions for electric vehicles. The effectiveness of the proposed system is investigated experimentally using a simulated cabin placed in a temperature and humidity-controlled test chamber. The experimental results confirm that the HVAC system achieves the required cooling, heating and defog/dehumidification functions and meets the corresponding standards. Moreover, the application of HVAC in EVs could lead to significant electrical power saving effect.

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