Air - for Health and Comfort, An Analysis of HVAC Systems' Performance in Theory and Practice
(2002) In Report TVBH 1013.- Abstract
- One part of the objective is to analyze how different ventilation systems perform in practice when it comes to supplying and exhausting designed air flow in different outdoor and indoor conditions. The other part is to analyze the design criterias and the energy use of a variable air volume system based on controlled static pressure at the branch duct level and supplying outdoor air only. To investigate the technical status of ventilation systems, the result from the compulsory testing and examination of ventilation systems (OVK) is used. A multi-zone model (COMIS) is used to study the air flow in a multi-family building. Two ventilation systems are analyzed with the same building; the mechanical exhaust and the mechanical supply and... (More)
- One part of the objective is to analyze how different ventilation systems perform in practice when it comes to supplying and exhausting designed air flow in different outdoor and indoor conditions. The other part is to analyze the design criterias and the energy use of a variable air volume system based on controlled static pressure at the branch duct level and supplying outdoor air only. To investigate the technical status of ventilation systems, the result from the compulsory testing and examination of ventilation systems (OVK) is used. A multi-zone model (COMIS) is used to study the air flow in a multi-family building. Two ventilation systems are analyzed with the same building; the mechanical exhaust and the mechanical supply and exhaust system. Fundamental pressure loss equations, measurements and a computer program are used to determine how much the air flow at the air terminals on a branch with controlled static pressure differs. A model is developed to determine the optimal supply air temperature with respect to energy use. An average of 34% of the studied ventilation systems performed as intended. Both the mechanical exhaust and the mechanical supply and exhaust air system showed sensitiveness to outdoor temperature, building airtightness and wind. When the static pressure is controlled to be constant at the branch duct level it is possible to vary the air flow to different zones without measuring the individual flow and without significantly influence the air flow to other zones. When using 100% outdoor air the indoor air quality will be improved during most of the year. There is a great potential in controlling the supply air temperature optimally to reduce the energy use. (Less)
- Abstract (Swedish)
- Popular Abstract in Swedish
Syftet är att dels studera olika ventilationssystems förmåga att tillföra och föra bort luftflöden. Den andra delen av syftet är att studera konstruktionskriterier och energi användning för ett variabelflödessystem baserat på konstanttryckshållning av det statiska trycket på grenkanalnivå och som endast tillför uteluft. Ventilationssystemens luftflöden studeras med hjälp av resultat från den obligatoriska ventilationskontrollen (OVK) och dels genom simulering i ett multi-zon program av en byggnad med dels the mekaniska frånluftssystemet och dels med det mekaniska från- och tilluftssystemet. Genom grundläggande tryckfallsekvationer, luftflödesmätningar och ett program för beräkningar av luftflöden... (More) - Popular Abstract in Swedish
Syftet är att dels studera olika ventilationssystems förmåga att tillföra och föra bort luftflöden. Den andra delen av syftet är att studera konstruktionskriterier och energi användning för ett variabelflödessystem baserat på konstanttryckshållning av det statiska trycket på grenkanalnivå och som endast tillför uteluft. Ventilationssystemens luftflöden studeras med hjälp av resultat från den obligatoriska ventilationskontrollen (OVK) och dels genom simulering i ett multi-zon program av en byggnad med dels the mekaniska frånluftssystemet och dels med det mekaniska från- och tilluftssystemet. Genom grundläggande tryckfallsekvationer, luftflödesmätningar och ett program för beräkningar av luftflöden i kanalsystem analyseras systemet baserat på konstantryckshållning av det statiska trycket. En modell byggs upp för beräkning av fläkt-, värme- och kylenergianvändningen i två olika klimat av systemet. För at minimera energianvändningen optimeras tilluftstemperaturen. Endast 34% av systemen som undersökts enligt den obligatoriska ventilationskontrollen presterade enligt de projekterade värdena. Både det mekaniska frånluftssystemet och det mekaniska från- och tilluftsystemet visade på känslighet gentemot utomhustemperaturen, byggnadens täthet och vind. Genom att kontrollera det statiska trycket kan luftflödet till olika zoner varieras utan att flödet mäts vid varje zon och utan att de övriga zonernas luftflöden påverkas. Det finns en stor energibesparingspotential i att optimera tilluftstemperaturen. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/464749
- author
- Engdahl, Fredrik LU
- supervisor
- opponent
-
- Docent Agemar, Lennart, Chalmers
- organization
- publishing date
- 2002
- type
- Thesis
- publication status
- published
- subject
- keywords
- Byggnadsteknik, Building construction, indoor air quality, HVAC, infiltration, ventilation, VAV
- in
- Report TVBH
- volume
- 1013
- pages
- 152 pages
- publisher
- Byggnadsfysik LTH, Lunds Tekniska Högskola
- defense location
- Lecture hall V:C, V-building, John Ericssons väg 1, Lund University Faculty of Engineering
- defense date
- 2002-06-07 10:15:00
- external identifiers
-
- other:TVBH-1013
- ISSN
- 0349-4950
- ISBN
- 91-88722-24-4
- language
- English
- LU publication?
- yes
- additional info
- Article: F. Engdahl, Evaluation of Swedish Ventilation Systems, Building and Environment, Vol. 33, No 4, pp. 197-200, 1998F. Engdahl, Stability of Mechanical Exhaust System, Indoor Air, No. 9, pp. 282-289, 1999.F. Engdahl, Stability of Mechanical Exhaust and Supply Systems, Proceedings of the 7th International Conference on Air Distribution in Rooms, pp. 1207-1212, 2000.F. Engdahl, A. Svensson, Pressure Controlled Variable Air Volume System, Submitted to Energy and Buildings, 2002.F. Engdahl, D. Johansson, Optimal Supply Air Temperature with Respect to Energy Use in a Variable Air Volume System, Submitted to Energy and Buildings, 2002.
- id
- 07577f67-5bad-461b-b202-e6e4930741da (old id 464749)
- alternative location
- http://www.byfy.lth.se/fileadmin/byfy/files/TVBH-1000pdf/TVBH-1013FE.pdf
- date added to LUP
- 2016-04-01 16:04:15
- date last changed
- 2019-05-23 17:23:29
@phdthesis{07577f67-5bad-461b-b202-e6e4930741da,
abstract = {{One part of the objective is to analyze how different ventilation systems perform in practice when it comes to supplying and exhausting designed air flow in different outdoor and indoor conditions. The other part is to analyze the design criterias and the energy use of a variable air volume system based on controlled static pressure at the branch duct level and supplying outdoor air only. To investigate the technical status of ventilation systems, the result from the compulsory testing and examination of ventilation systems (OVK) is used. A multi-zone model (COMIS) is used to study the air flow in a multi-family building. Two ventilation systems are analyzed with the same building; the mechanical exhaust and the mechanical supply and exhaust system. Fundamental pressure loss equations, measurements and a computer program are used to determine how much the air flow at the air terminals on a branch with controlled static pressure differs. A model is developed to determine the optimal supply air temperature with respect to energy use. An average of 34% of the studied ventilation systems performed as intended. Both the mechanical exhaust and the mechanical supply and exhaust air system showed sensitiveness to outdoor temperature, building airtightness and wind. When the static pressure is controlled to be constant at the branch duct level it is possible to vary the air flow to different zones without measuring the individual flow and without significantly influence the air flow to other zones. When using 100% outdoor air the indoor air quality will be improved during most of the year. There is a great potential in controlling the supply air temperature optimally to reduce the energy use.}},
author = {{Engdahl, Fredrik}},
isbn = {{91-88722-24-4}},
issn = {{0349-4950}},
keywords = {{Byggnadsteknik; Building construction; indoor air quality; HVAC; infiltration; ventilation; VAV}},
language = {{eng}},
publisher = {{Byggnadsfysik LTH, Lunds Tekniska Högskola}},
school = {{Lund University}},
series = {{Report TVBH}},
title = {{Air - for Health and Comfort, An Analysis of HVAC Systems' Performance in Theory and Practice}},
url = {{https://lup.lub.lu.se/search/files/4558413/8081179.pdf}},
volume = {{1013}},
year = {{2002}},
}