Demand controlled ventilation by room CO2 concentration: a comparison of simulated energy savings in an auditorium space

1991 ◽  
Vol 17 (2) ◽  
pp. 87-96 ◽  
Author(s):  
B.F. Warren ◽  
N.C. Harper
Keyword(s):  
Energy Savings ◽  
Co2 Concentration ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation

scholarly journals DEVELOPMENT OF A NEW CO2-BASED DEMAND-CONTROLLED VENTILATION STRATEGY USING ENERGYPLUS

2017 ◽  
Author(s):  
Behrang Chenari ◽  
Francisco Bispo Lamas ◽  
Adélio Rodrigues Gaspar ◽  
Manuel Gameiro da Silva
Keyword(s):  
Energy Efficiency ◽  
Indoor Air ◽  
Energy Use ◽  
Energy Savings ◽  
Environmental Condition ◽  
Ventilation Strategy ◽  
Controlled Ventilation ◽  
New Strategy ◽  
Demand Controlled Ventilation ◽  
Air Conditioning Systems

A significant amount of energy is being used by ventilation and air conditioning systems to maintain the indoor environmental condition in a satisfactory and comfortable level. Many buildings, either new or existing (throughout their renovation process) are subjected to energy efficiency requirements but these must not be in the expenses of indoor environmental conditions. For instance, indoor air quality (IAQ) has to be considered while improving energy efficiency, otherwise occupants might be exposed to inappropriate indoor environment.Demand-controlled ventilation (DCV) is a method that provides comfortable IAQ level with lowest energy use. In this paper, the main objective is developing a new CO2-based DCV strategy and simulating it using EnergyPlus. The IAQ and energy consumption associated to this strategy have been compared with the results of CO2-based DCV strategies previously developed by the same authors in another article. The comparison shows that the new strategy performs better, both in energy use and IAQ. The recorded energy savings ranged between 6-14% comparing with the previously developed strategies while IAQ slightly improved.

scholarly journals Humidity-Sensitive Demand-Controlled Ventilation Applied to Multi-Unit Residential Building – Performance and Energy Consumption in Dfb Continental Climate

2020 ◽  
Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Ventilation System ◽  
Residential Building ◽  
Primary Energy ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation ◽  
Continental Climate

A humidity-sensitive demand-controlled ventilation system is known for many years. It has been developed and commonly applied in regions with an oceanic climate. Some attempts were made to introduce this solution in Poland in a much severe continental climate. The article evaluates this system's performance and energy consumption applied in an 8-floor multi-unit residential building, virtual reference building described by the National Energy Conservation Agency NAPE, Poland. The simulations using the computer program CONTAM were performed for the whole hating season for Warsaw's climate. Besides passive stack ventilation that worked as a reference, two versions of humidity-sensitive demand-controlled ventilation were checked. The difference between them lies in applying the additional roof fans that convert the system to hybrid. The study confirmed that the application of demand-controlled ventilation in multi-unit residential buildings in a continental climate with warm summer (Dfb) leads to significant energy savings. However, the efforts to ensure acceptable indoor air quality require hybrid ventilation, which reduces the energy benefits. It is especially visible when primary energy use is analyzed.

scholarly journals CO2-based grey-box model to estimate airflow rate and room occupancy

2019 ◽  
Vol 111 ◽  
pp. 04036
Author(s):  
Sebastian Wolf ◽  
Maria Justo Alonso ◽  
Davide Calì ◽  
John Krogstie ◽  
Hans Martin Mathisen ◽  
...  
Keyword(s):  
Differential Equations ◽  
Measurement Errors ◽  
Energy Savings ◽  
Box Model ◽  
Airflow Rate ◽  
Building Stock ◽  
Deterministic Models ◽  
Existing Building ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation

In the existing building stock, heating, cooling and ventilation often run on fixed schedules assuming maximal occupancy. However, fitting the control of the HVAC system to the building’s real demand offers large potential for energy savings over the status quo. Building occupants’ presence as well as mechanically supplied and infiltrated airflow rates provide information that enables to define tailored strategies for demand-controlled ventilation. Hence, real-time estimations of these quantities are a valuable input to demand-controlled built environments. In this work, the use of stochastic differential equations (SDE) to estimate the room occupancy, infiltration air-rate and ventilation air-rate is investigated. In particular, a grey-box model based on a carbon dioxide (CO2) mass balance equation is presented. The model combines knowledge about the physical system with statistical, data-driven parameter estimation. Furthermore, the proposed model contains uncertainty parameters. This is in contrast to purely deterministic models based on ordinary differential equations, where uncertainty is usually disregarded. The suggested model has been tested in a naturally ventilated and in a mechanically ventilated environment; the performance in these two cases has been compared. We show that the ability to address measurement errors and non-homogeneous conditions in the room air implies that the suggested SDE-based grey-box approach is suitable in the context of demand-controlled ventilation.

scholarly journals Humidity-Sensitive, Demand-Controlled Ventilation Applied to Multiunit Residential Building—Performance and Energy Consumption in Dfb Continental Climate

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6669
Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Residential Buildings ◽  
Residential Building ◽  
Primary Energy ◽  
Controlled Ventilation ◽  
Carbon Dioxide Concentrations ◽  
Demand Controlled Ventilation ◽  
Continental Climate ◽  
Ventilation Systems

Humidity-sensitive, demand-controlled ventilation systems have been in use for many years in regions with oceanic climates. Some attempts have been made to apply this technology in Poland, which has a continental climate. This article evaluates the performance and energy consumption of such a system when applied in an eight-floor, multiunit, residential building, i.e., the virtual reference building described by the National Energy Conservation Agency (NAPE), Poland. Simulations using the computer program CONTAM were performed for the whole heating season based upon the climate in Warsaw. Besides passive stack ventilation, that served as a reference, two ventilation systems were studied: one standard and one “hybrid” system with additional roof fans. This study confirmed that the application of humidity-sensitive, demand-controlled ventilation in multiunit residential buildings in a continental climate (Dfb) led to significant energy savings (up to 11.64 kWh/m2 of primary energy). However, the operation of the system on higher floors was found to be ineffective. Ensuring consistent operation of the system on all floors required supplementary fans. The introduction of a hybrid mode reduced carbon dioxide concentrations by approximately 32% in the units located in the upper part of the building. The energetic effect in such cases depends strongly on the electricity source. In the case of the national energy grid, savings of primary energy would be relatively low, i.e., 1.07 kWh/m2, but in the case of locally produced renewable energy, the energy savings would be equal to 5.18 kWh/m2.

scholarly journals Comparison of Multi-Control Strategies for the Control of Indoor Air Temperature and CO2 with OpenModelica Modeling

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4425
Author(s):  
Wei Wang ◽  
Xiaofang Shan ◽  
Syed Asad Hussain ◽  
Changshan Wang ◽  
Ying Ji
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air ◽  
Pid Control ◽  
Control Strategies ◽  
Co2 Concentration ◽  
Control Methods ◽  
Outdoor Air ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation

As most residents spend more than 90% of their time in buildings, acceptable and reasonable control of both indoor thermal comfort and air quality is imperative to ensure occupants’ health status and work productivity. However, current control strategies generally take either thermal comfort or indoor air quality as a single loop, rather than the concurrent control of two. To analyze their mutual influence, this study investigated the performance of three multi-control approaches, i.e., proportional integral derivative (PID) control of thermal comfort and a fixed outdoor air ratio, PID control of thermal comfort and design outdoor air rate, and PID control of thermal comfort and occupancy-based demand-controlled ventilation. As a pilot study, three typical control methods were implemented to a multi-zone building via OpenModelica modeling. The results indicate that indoor air temperature can be well-maintained under three control methods, however, the CO2 concentration under the fixed outdoor air ratio was over 1000 ppm, leading to poor indoor air quality. The control strategy with the design outdoor air rate could not properly ensure the CO2 concentration, due to the over-ventilated or under-ventilated phenomena, subsequently resulting in unnecessary energy waste. The occupancy-based demand controlled ventilation could maintain the CO2 concentration under the set-point with an intermediate power energy utilization.

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