Automatic operation method using wireless sensor networks for variable refrigerant flow system: Switchless control variable refrigerant flow system

Suzuki, Toshihiro; Shimoda, Yoshiyuki; Kobayashi, Akito et al.

Energy and Buildings, 2025, 331, 115379

Number of Access:454（2025-10-27 10:10 Counts）

Identifier to cite or link to this item: https://hdl.handle.net/11094/100577

Link to primary information 

File Format Terms of use Size Views Date.Available Description information
EnergyBuild_331_115379 pdf None 14.1 MB 57 2025.03.14  
Creative Commons : Attribution - NonCommercial - NoDerivatives

Item Information

Output File Export EndNote Basic Export Mendeley

Title
Automatic operation method using wireless sensor networks for variable refrigerant flow system: Switchless control variable refrigerant flow system
Creator
NRID
1000000522070 1000000522070
ORCID
0009-0003-3443-4173 0009-0003-3443-4173
researchmap permalink
toshihiro.suzuki toshihiro.suzuki
Scopus Author ID
55731719800 55731719800
CreatorName
Suzuki, Toshihiro
NRID
1000020226278 1000020226278
ORCID
0000-0002-4487-0089 0000-0002-4487-0089
researchmap permalink
read0014119 read0014119
Scopus Author ID
15081121700 15081121700
CreatorName
Shimoda, Yoshiyuki
CreatorName
Kobayashi, Akito
CreatorName
Shiochi, Sumio
Subject
Energy efficiency
Medium-sized buildings
Sensor networks
Variable refrigerant flow system
Description
Suzuki T., Shimoda Y., Kobayashi A., et al. Automatic operation method using wireless sensor networks for variable refrigerant flow system: Switchless control variable refrigerant flow system. Energy and Buildings 331, 115379 (2025); https://doi.org/10.1016/j.enbuild.2025.115379.
Abstract
Variable refrigerant flow (VRF) systems autonomously operate using built-in sensors regulated by remote settings and indoor unit intake temperatures. However, in larger spaces with multiple indoor and outdoor units, autonomous VRF systems lack the benefits of an integrated system, such as balanced load distribution, coordinated operation, and efficient ventilation. To overcome these challenges, the authors developed a “switchless VRF system” designed for small to medium-sized buildings. This system improves comfort and energy efficiency by eliminating extensive control mechanisms and switches, ensuring uniform performance and greater energy saving. We performed detailed demonstration experiments to evaluate the system's effectiveness across four key functions (pre-cooling and pre-heating, human sensing HVAC control, outdoor unit rotation control, and indoor unit fan power reduction functions). In the first control, the VRF system demonstrated significant energy efficiency, achieving 18 % energy saving in summer pre-cooling. In the second, the human-detection ventilation control effectively modulated the ventilation volume by real-time monitoring of the number of occupants, resulting in approximately 35 % energy saving. In the third, the rotational control strategy enhanced the average COP of the outdoor units by 17.7 %. In the fourth, a reduction in indoor-unit fan power led to an overall power consumption decrease of 8.6 % by ceasing fan operation when the thermostat was deactivated. This innovation addresses the modern needs of building management and energy conservation, making it a viable option for enhancing HVAC operations.
Publisher
Elsevier Ltd
Source Title
Energy and Buildings
Volume (Issue)
331
Page
115379
Date of Issued
2025-03-15
Language
English
Handle URL
https://hdl.handle.net/11094/100577
PISSN
03787788
Relation.isIdenticalTo
DOI (Publisher Version)
https://doi.org/10.1016/j.enbuild.2025.115379
Access Rights
open access
CopyRight
This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
oaire:version
Version of Record
Category
学術雑誌論文 Journal Article