State-of-the-art review of CO2 demand controlled ventilation technology
                        and application

Emmerich, Steven J.; Persily, Andrew K.

doi:10.6028/nist.ir.6729

Cited by 120 publications

(108 citation statements)

References 28 publications

(27 reference statements)

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“…According to [17] implementing DCV systems in schools can save from 20% to 40% of the air-conditioning energy consumption. This argument has certainly contributed to the frequent use of DCV systems in USA school buildings.…”

Section: Demand Control Ventilationmentioning

confidence: 99%

Reconciling Indoor Air Quality and Energy Efficiency in Air-Conditioned Classrooms: Case Studies for Portugal and Macao

Duarte¹,

Beltrão-Coelho²

2013

IJESD

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Abstract-Growing awareness on the subject of classroom's indoor air quality and concerns regarding the probable link between indoor air quality, student's attendance and academic performance, support recent legislation limiting classroom's indoor pollutant concentrations. A consequence of this legislation is the generalized shift towards air-conditioned classrooms and increased budgets for schools energy running costs. According to the scientific literature, demand control ventilation systems are suited for classrooms, ensuring indoor air quality and thermal comfort with significant energy savings. Based on detailed building energy simulation this paper compares a demand control ventilation system and a (traditional) constant air volume system considering a typical classroom located in two distinct climatic regions: Portugal and Macao. Based on hourly results of classroom's indoor CO 2 concentrations and indoor air temperatures, and on annual air-conditioning energy consumptions, advantages of the demand control ventilation system are discussed.Index Terms-Classroom indoor air quality, demand control ventilation, energy efficiency, thermal comfort. I. INTRODUCTIONSeveral European governments have decided to invest in rebuilding and refurbishing their stock of existing public schools. According to Mumovic [1], UK's government is commited to a £45 billion program dedicated to the rebuilding of secondary schools in England and Wales. Gertis [2] states that during the current decade, Germany will invest €73 billion in the rebuilding and refurbishing of public school buildings. The Portuguese government has also invested in the rebuilding of over 100 existing secondary schools [3] and a trend that favors cyclic rebuilding instead of new construction is foreseeable in Europe, in the future.These large scale public investments take place at a time of growing awareness on the subject of classroom's indoor air quality (IAQ) [4], [5] and of concern regarding the probable link between IAQ and student attendance and academic performance [6] having different indoor air quality and green building labeling methods available.Traditionally, European classrooms were naturally ventilated; in warmer Mediterranean countries classrooms were often neither heated nor cooled. However, the need to ensure indoor pollutant concentrations below specific maxima imposes the use mechanical ventilation; therefore all rebuilt and refurbished schools now include heating and cooling systems, used to remove the fresh air thermal loads and remove the classroom thermal loads.These "new" retrofitted schools, with air-conditioned classrooms, represent a "paradigm shift" in Europe, especially for Mediterranean countries. An important consequence of this "shift" is being felt at school administration boards, which are now facing a significant increase in schools energy running costs. The use of energy efficient air-conditioned systems is essential to minimize the problems associated with excessive increase in energy running costs.Macao and southwest Asia...

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Section: Demand Control Ventilationmentioning

confidence: 99%

Reconciling Indoor Air Quality and Energy Efficiency in Air-Conditioned Classrooms: Case Studies for Portugal and Macao

Duarte¹,

Beltrão-Coelho²

2013

IJESD

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“…For this reason, frequency of the times when CO2 levels were higher than 1000, 1500 and 5000 parts per million (ppm) are reported. The 1000 ppm value is the target value suggested by BS EN 15251:2007 [29] as the acceptable IAQ while 1500 ppm is the concentration value in which usually all the occupants show some symptom of sick building syndrome [30] and the 5000 ppm is the concentration value in which occupants' health can be affected [31].…”

Section: Methodsmentioning

confidence: 99%

The Effects of Air Permeability, Background Ventilation and Lifestyle on Energy Performance, Indoor Air Quality and Risk of Condensation in Domestic Buildings

Hashemi

Khatami

2015

Sustainability

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Effective and efficient ventilation is essential when improving energy performance and Indoor Air Quality (IAQ) of buildings. Reducing air permeability can considerably improve the energy performance of buildings; however, making the buildings more airtight may result in lower rates of natural ventilation which may in turn increase the risks of condensation and unacceptable IAQ. This study evaluates the effects of different air permeability rates, background ventilation and occupants' lifestyles on the energy performance as well as the risk of condensation and CO2 concentration in domestic buildings. Dynamic computer simulations were conducted in EnergyPlus. Results indicated direct relations between the ventilation rates, energy performance and IAQ. Higher air permeability along with background ventilation resulted in considerably better IAQ while energy consumption increased by up to four times. Occupants' lifestyles were identified as a major contributor to the risk of condensation.

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“…The International Energy Agency (IEA) Annex 18 project (1987Annex 18 project ( -1992 published six reports related to DCV covering review of the state of the art, a sensor market survey, a sensor test, case studies, and a source book (Raatschen 1990(Raatschen , 1991Fahlen and Andersson 1992;Mansson and Svennberg 1992;Mansson 1992). Emmerich and Persily (2001) comprehensively reviewed the literature on CO 2 -based demand-controlled ventilation working from their previous review (Emmerich and Persily 1997). Topics reviewed include field demonstration projects, computer simulation studies, studies of sensor performance and location, regulatory and standard requirements, and applications of the approach.…”

Section: Demand Controlled Ventilationmentioning

confidence: 99%

Review of Literature on Terminal Box Control, Occupancy Sensing Technology and Multi-zone Demand Control Ventilation (DCV)

Liu¹,

Dasu²,

Zhang³

2012

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Executive summaryThis report presents the results of an analysis of published studies and other literature concerned with terminal box control, occupancy sensing technology, and multi-zone demand control ventilation (DCV) in commercial buildings. To meet the ventilation needs of building occupants, heating, ventilating and airconditioning systems provide outdoor air. For many systems, air is brought into a commercial building through air-handling units, which supply conditioned air to many thermal zones in the building. The airhandling units mix outdoor air in a controlled proportion with recirculated air and then cool the mixture before distribution to the terminal boxes. Terminal boxes usually serve a single building zone, controlling the air flow rate to the zone and reheating the air, if it is too cool for the zone served. Each terminal box has a minimum air flow rate set so that it meets the ventilation requirements of the occupants of the zone the box serves. This minimum air flow rate is commonly designed as a constant value based on the design occupancy of the zone served, which usually corresponds to the maximum occupancy.In practice, control system integrators and installers often set the minimum air flow rate for ventilation to between 30% and 50% of the terminal box maximum air flow rate. Building occupancy, however, varies dynamically. Conference rooms, cafeterias, break rooms, auditoriums, and other assembly spaces are often unoccupied for significant periods of time. Office occupancy varies during the course of a work day, from day to day, and over the longer term because of meetings in the office, attendance of meetings elsewhere, business travel, changing room functions during remodeling, and variations in staffing. The resulting over-ventilation, during times when the space has less than maximum occupancy or is unoccupied, wastes significant fan power, resulting in energy waste, and even causing discomfort for occupants in some spaces (e.g., conference rooms) from overcooling.Carbon-dioxide-based demand control ventilation has existed for a number of years; however, as currently used, it controls outdoor-air intake by the air handler only, not ventilation of individual zones or rooms. The need for frequent recalibration (e.g., annually) and the high cost of installation for each zone (or room) makes CO 2 -based control of ventilation at terminal boxes impractical. A multi-lab report (Brambley et al. 2005) for the U.S. Department of Energy (DOE) on advanced sensors and controls identifies a need for "development of sensors to determine occupancy number and population distribution within buildings." There are no such terminal unit controllers on the market today to modulate air flow to zones based on actual occupancy. The Advanced Energy Retrofit Guide (AERG) for Office Buildings, sponsored by DOE's Building Technology Program (BTP), reveals that a 4% reduction in whole-building energy consumption can be achieved by implementing occupancy-based control (OBC) in conference rooms alone ).This repor...

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State-of-the-art review of CO2 demand controlled ventilation technology and application

Cited by 120 publications

References 28 publications

Reconciling Indoor Air Quality and Energy Efficiency in Air-Conditioned Classrooms: Case Studies for Portugal and Macao

Reconciling Indoor Air Quality and Energy Efficiency in Air-Conditioned Classrooms: Case Studies for Portugal and Macao

The Effects of Air Permeability, Background Ventilation and Lifestyle on Energy Performance, Indoor Air Quality and Risk of Condensation in Domestic Buildings

Review of Literature on Terminal Box Control, Occupancy Sensing Technology and Multi-zone Demand Control Ventilation (DCV)

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