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.

Research on Demand Controlled Ventilation Strategy for Laboratory Ventilation System

2013 ◽  
Vol 805-806 ◽  
pp. 1558-1561
Author(s):  
Zhen Hua Bao
Keyword(s):  
Indoor Air ◽  
Energy Use ◽  
Ventilation System ◽  
Substantial Reduction ◽  
Ventilation Rate ◽  
Outdoor Air ◽  
Air Exchange Rate ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation ◽  
Rate Requirement

Reducing the amount of outdoor air entering a space has distinct advantages for ventilation system. However, it often brings the consequence of depressing indoor air quality (IAQ). For laboratories, on average, the laboratory IAQ conditions of low TVOCs and low particulates permitted the substantial reduction of minimum air change rates. With many modern laboratories operating with fewer fume hoods and more energy-efficient equipment and lighting, the labs minimum air exchange rate requirement is often the dominant energy use driver. Current codes or specifications for laboratories ventilation system are the most straight forward approaches. They do not optimize a laboratory's ventilation rate, or verify whether the intended levels of safety and comfort have been achieved by the labs design. Demand controlled ventilation (DCV) can also avoid over-ventilation by providing outdoor air rates based on actual occupancy rather than on design occupancy or full occupancy.

scholarly journals Impact of Typical Faults Occurring in Demand-controlled Ventilation on Energy and Indoor Environment in a Nordic Climate

2020 ◽  
Vol 172 ◽  
pp. 09006
Author(s):  
Kamilla Heimar Andersen ◽  
Sverre B. Holøs ◽  
Aileen Yang ◽  
Kari Thunshelle ◽  
Øystein Fjellheim ◽  
...  
Keyword(s):  
Indoor Environment ◽  
Energy Use ◽  
Qualitative Interviews ◽  
Building Performance ◽  
Local Approach ◽  
Performance Simulation ◽  
Building Performance Simulation ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation ◽  
The Impact

This study evaluates typical faults occurring in demand-controlled ventilation (DCV) system and the impact on three output results: energy use, thermal comfort, and indoor air quality. The methodologies used in this study were qualitative interviews of selected Norwegian Heating Ventilation Air Condition (HVAC) system experts and numerical modeling using the building performance simulation tool IDA ICE. The faults deduced from the qualitative interviews were modeled as the fault's different consequences to account for a large variety of faults. With a Norwegian school classroom as a case study, a local approach applying a one-at-a-time (OAT) simulation was used to perform an analysis of the extreme fault conditions that can occur. The results from the fault modeling demonstrated that greater attention is needed to avoid faults in the HVAC systems due to its impact on the indoor environment quality and energy efficiency of buildings.

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.

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