Variable Air Volume System Application in Museums

Relative humidity and temperature control is key in museums, galleries, libraries and archives. Normally constant volume (CV) air handling units (AHUs) with reheat coils are applied in these buildings. Setting a low supply air temperature limits the highest humidity level; however, reheat coils have to be used to maintain space temperature due to constant supply airflow. As a result, simultaneous heating and cooling exists with excessive energy consumption. It is well known that variable air volume (VAV) technologies can reduce simultaneous heating and cooling as well as fan power. This paper presents the detail VAV system retrofit for the existing CV system, control sequence development and system performance evaluation in a museum facility at Omaha, Nebraska. Variable Frequency Drives (VFDs) were installed for the supply fan on the AHUs. Space humidity and temperature, heating and cooling energy consumption, and fan power were measured. The measurements showed that the space humidity and temperature was maintained within the required range under VAV operation while the reheat consumption was reduced by up to 85% and the fan power consumption was reduced by 90% under partial cooling loads.

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Terminal Box Minimum Airflow Optimization of Single Duct Air Handling Units

ASME 2007 Energy Sustainability Conference ◽

10.1115/es2007-36093 ◽

2007 ◽

Author(s):

YoungHum Cho ◽

Gang Wang ◽

Mingsheng Liu

Keyword(s):

Energy Consumption ◽

Air Temperature ◽

Thermal Environment ◽

Variable Air Volume ◽

Heating And Cooling ◽

Air Handling Unit ◽

Simultaneous Heating ◽

Save Energy ◽

Heating Loads ◽

Simultaneous Heating And Cooling

Terminal boxes control space conditions in variable air volume (VAV) air-handling unit (AHU) systems. Terminal boxes either modulate airflow with a control damper or adjust discharge air temperature with a reheat coil. Terminal boxes will have a significant amount of simultaneous heating and cooling and AHUs will consume more fan power if the minimum airflow is higher than required. On the other hand, conditioned space will have indoor air quality (IAQ) problems with less air circulation if the minimum airflow is less than required. The objective of this study is to optimize the minimum airflow ratio to improve thermal environment and save energy consumption. In this study, the problem of current fixed minimum airflow ratio of terminal box is analyzed and variable minimum airflow ratio as an alternative is suggested. The results of this study show that variable minimum airflow ratio can stably maintain the set room air temperature and reduce energy consumption for varying heating loads compared to the conventional fixed minimum airflow ratio.

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Full-scale operation of a novel two-pipe active beam system for simultaneous heating and cooling of office buildings

E3S Web of Conferences ◽

10.1051/e3sconf/201911101073 ◽

2019 ◽

Vol 111 ◽

pp. 01073

Author(s):

Alessandro Maccarini ◽

Göran Hultmark ◽

Niels C. Bergsøe ◽

Alireza Afshari

Keyword(s):

Room Temperature ◽

Energy Performance ◽

Physical Parameters ◽

Heating And Cooling ◽

System A ◽

A Value ◽

Beam System ◽

Simultaneous Heating ◽

Simultaneous Heating And Cooling ◽

Cooling Loads

This paper presents an investigation on the operation of a novel active beam system installed in an office building located in Jönköping, Sweden. The system consists of two parts: a dedicated outdoor air system (DOAS) to satisfy latent loads and ventilation requirements, and a water circuit to meet sensible heating and cooling loads. The novelty of the system is in relation to the water circuit, which is able to provide simultaneous heating and cooling through a single water loop that is near the room temperature. The energy performance of the system is currently being monitored through a number of sensors placed along the water circuit. Relevant physical parameters are being measured and data are available through a monitoring system. A preliminary analysis shows that the system is performing as designed. Results are shown for a typical week in winter, spring and summer. In particular, the supply water temperature in the circuit was between 20°C (in summer) and 23.2°C (in winter). The maximum supply/return temperature difference was found in summer and it assumed a value of 1.5 K. It is noticed that in spring supply and return water temperatures almost overlap.

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MASTERPLANNER: A CENTRAL UTILITY PLANT DESIGN AND OPTIMIZATION TOOL

10.31224/osf.io/pr2ua ◽

2021 ◽

Author(s):

Pouya Rezazadeh Kalehbasti ◽

Te Qi

Keyword(s):

Life Cycle Cost ◽

Energy Use ◽

Operating Cost ◽

Plant Design ◽

Web Based ◽

Design And Optimization ◽

Heating And Cooling ◽

Simultaneous Heating ◽

Simultaneous Heating And Cooling ◽

Cooling Loads

This paper presents a web-based software for designing optimal central utility plants. This tool can receive user-defined load profiles or generate typical load profiles based on user-specified combination and areas of 16 reference building types. The software then solves a linear-programming optimization comprising 8760 sets of equations and constraints to design central plant configurations with minimal first cost, operating cost, life-cycle cost, energy use, or marginal carbon emissions. The tool also calculates simultaneous heating and cooling loads to evaluate using heat-recovery chillers, and it can design both hot and cold thermal energy storage as well as water-side economizers.

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Towards Sustainable Energy Retrofitting, a Simulation for Potential Energy Use Reduction in Residential Buildings in Palestine

Energies ◽

10.3390/en14133876 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3876

Author(s):

Sameh Monna ◽

Adel Juaidi ◽

Ramez Abdallah ◽

Aiman Albatayneh ◽

Patrick Dutournie ◽

...

Keyword(s):

Energy Consumption ◽

Energy Use ◽

Energy Savings ◽

Residential Buildings ◽

Residential Building ◽

Simulation Models ◽

Water Heating ◽

Heating And Cooling ◽

Space Cooling ◽

Cooling Loads

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.

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Energy efficient refrigeration system with simultaneous heating and cooling

Materials Today Proceedings ◽

10.1016/j.matpr.2021.03.072 ◽

2021 ◽

Author(s):

P. Nikhil Babu ◽

D. Mohankumar ◽

P. Manoj Kumar ◽

M. Makeshkumar ◽

M. Gokulnath ◽

...

Keyword(s):

Energy Efficient ◽

Refrigeration System ◽

Heating And Cooling ◽

Simultaneous Heating ◽

Simultaneous Heating And Cooling

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

E3S Web of Conferences ◽

10.1051/e3sconf/20183804012 ◽

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.

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