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

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.

Download Full-text

Variable Air Volume System Application in Museums

ASME 2007 Energy Sustainability Conference ◽

10.1115/es2007-36058 ◽

2007 ◽

Author(s):

Zhan Wang ◽

Bin Zheng ◽

Wenlong Xu ◽

Gang Wang ◽

Mingsheng Liu

Keyword(s):

Energy Consumption ◽

System Control ◽

Variable Air Volume ◽

Heating And Cooling ◽

Air Volume ◽

Variable Frequency Drives ◽

Air Handling Units ◽

Simultaneous Heating ◽

Simultaneous Heating And Cooling ◽

Cooling Loads

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.

Download Full-text

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.

Download Full-text