Life Cycle Cost Analysis of Air Conditioning Systems in a Perimeter Zone for a Variable Air Volume System in Office Buildings

The main factor contributing to greenhouse gas emissions is the building up of the surrounding area. Studies have shown that buildings globally consume 30-40 % of energy use and release 40-50 % of global carbon dioxide emissions. Among all systems in houses, heating, ventilation and air conditioning (HVAC) systems are by far the most energy intensive. They consume approximately 50 % of the total energy demand of buildings. However, the systems are some of the most important systems in today's buildings. The number of these systems that are being installed has increased dramatically over the past few years. This is mainly due to the increasing demands for thermal energy, comfort and climate change. This paper presents a feasibility and ecology study between two ventilation or air-conditioning systems: constant air volume (CAV) and variable air volume (VAV). One of the purposes of this work is to determine the energy costs for each of the systems. An air conditioning system that saves operating costs usually requires a large initial investment. In this case, engineers must decide whether it is worth paying the additional upfront costs for a system that has lower operating costs. Despite the low attractiveness from the point of view of the investor, the VAV systems reduce the amount of greenhouse gas emissions and the amount of energy resources for servicing the commercial sector. Such system have less metal consumption. Thus, the cost of metal processing is also reduced. The results of this study can contribute to the future selection of ventilation systems, as well as contribute to the design and improvement of the systems under study. Energy saving is one of the main reasons why VAV systems are very popular today for the design of ventilation and air conditioning systems for office buildings and in many industries abroad. With these systems, the volume of transported air is reduced as soon as the operating load falls below the maximum projected load. The calculation of emissions of harmful substances into the environment was made while ensuring the operation of CAV and VAV systems.

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Perancangan Sistem Tata Udara Ditinjau dari Aspek Energi dan Biaya pada Bangunan Hotel di Semarang

Engineering, MAthematics and Computer Science (EMACS) Journal ◽

10.21512/emacsjournal.v2i3.6594 ◽

2020 ◽

Vol 2 (3) ◽

pp. 97-106

Author(s):

Agus Marjianto ◽

Dave Mangindaan

Keyword(s):

Life Cycle ◽

Cost Analysis ◽

Life Cycle Cost ◽

Air Conditioning ◽

Tourism Industry ◽

Cost Calculation ◽

Life Cycle Cost Analysis ◽

Cooling Load ◽

Air Conditioning System ◽

Central Air Conditioning

[Design of air conditioning system based on the energy and costs aspect of hotel buildings in Semarang] Indonesia’s economic growth has been above 5% for the past few years. Tourism industry is one of the sectors that shows a significant progress. The improvement in tourism industry has to be supported with good hospitality industry as well. Air conditioning system is one of the main utilities in a hotel building. The design of the air conditioning system for a hotel building must pay close attention to the thermal comfort factor for the guests, safety factor, and energy and cost efficiency aspect of it. Air conditioning system design consists of cooling load calculation for the hotel, air conditioning system selection, energy and cost calculation using the life cycle cost analysis. The maximum cooling load in this hotel is 3.279 kW. From that cooling load, three alternative systems are being considered, which are the central air conditioning system using chiller machine that has constant flowrate, the central air conditioning system using chiller machine that has variable flowrate, and the split air conditioning system using VRF machine. Energy analysis and life cycle cost analysis for 20 years was performed to be able to decide the best system. From that energy and cost analysis it can be concluded that the second alternative, which is three units of chiller with variable discharge with a capacity of 1,100 kW for each chiller, is the best system for the hotel. This system has an energy consumption intensity value of 118 kWh/m2 per year and total cost of Rp. 87,707,416,390 for a period of 20 years.

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Comparison between Variable and Constant Refrigerant Flow Air Conditioning Systems in Arid Climate: Life Cycle Cost Analysis and Energy Savings

Sustainability ◽

10.3390/su131810374 ◽

2021 ◽

Vol 13 (18) ◽

pp. 10374

Author(s):

Georges Atallah ◽

Faris Tarlochan

Keyword(s):

Life Cycle ◽

Cost Analysis ◽

Life Cycle Cost ◽

Air Conditioning ◽

Sustainable Energy ◽

Economic Feasibility ◽

Life Cycle Cost Analysis ◽

Sustainable Solutions ◽

Present Worth ◽

Crf System

All over the world, there is a call to encourage sustainable energy thinking and implementation. There is an urgent need to consider sustainable solutions in any design projects that are able to reduce energy consumption. In the heating, ventilation, and air conditioning field, the rise of the variable refrigerant flow systems has made big progress. This study presents a life cycle cost analysis to evaluate the economic feasibility of constant refrigerant flow (CRF), and in particular, the conventional ducted unit air conditioning system and the variable refrigerant flow (VRF) system by using detailed cooling load profiles, as well as initial, operating, and maintenance costs. Two operating hours scenarios are utilized and the present worth value technique for life cycle cost analysis is applied to an existing office building located in Qatar, which can be conditioned by CRF and VRF systems. The results indicate that, although the initial cost of the VRF system is higher than that of the CRF system by 23%, the present worth cost of the VRF system is much lower than that of the CRF system at the end of the lifetime due to lower operating costs. There is also a significant energy saving of 27% by using VRF compared to the CRF. The implementation of these results on a national scale will promote the use of sustainable energy technologies such as the VRF system.

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