Paper 8: Volume 4 No.1 June 2005 Edition
Airtightness and Natural Ventilation:
A Case Study for
Dwellings in Poland
Marian B. Nantka
Department of Heating, Ventilation and Dust Removal
Technology,
Silesian Technical University, Gliwice 44-100, Poland
Abstract
Recently, in the Polish building sector, there has been a
conflict between ventilation techniques and a strong tendency toward
increasing building airtightness. Despite this increasing airtightness,
the ventilation process in the majority of these buildings still depends
on the uncontrolled supply of air through gaps in windows combined with
natural exhaust air ducts. To improve energy efficiency in the building
sector, more airtight envelopes constructed of modern materials of low air
leakage coefficient are being constructed. These coefficients are lower
(tighter) than commonly used standard values. While some contractors argue
that houses "need to breathe" and thus do not construct airtight
shells, others adopt a high airtightness strategy in which case controlled
ventilation is necessary. The main objective of this paper is to present
an analysis of airtightness and ventilation rates in typical Polish
dwellings. A case study involving a ground floor and top floor apartment
in a three storey apartment building is described. This includes an
analysis of airtightness, metabolic carbon dioxide concentration and
simulations of natural air flow. The results show that, as construction
becomes more airtight, continued reliance on natural leakage openings for
ventilation is not sufficient. In this case study building, for example,
ventilation was inadequate and carbon dioxide concentrations in excess of
3000 ppm could occur. To provide adequate natural ventilation, additional
window vents are needed. Ideally these should be coupled to CO2 and/or
humidity sensors to control the rate of airflow according to demand.
Key words: airtightness, natural ventilation, stack
ventilation, CO2 concentration, apartment buildings.
References
Fanger PO et al.: (2003)
“Indoor Environment”, Specjal Bulletin of
Silesian
Technical
University
, p245
Gliwice
.
Heiselberg P: (2004)
“Natural Ventialtion Design”, The International Journal of
Ventilation, 2, (4), pp295-312.
Kozicki J: (2003)
“Airtightness of Windows and their Relation to the Indoor Air Quality in
Dwellings”, Students Work,
Silesian
Technical
University
,
Gliwice
, p 126.
Liddament MW: (1996) “A
Guide to Energy Efficient Ventilation”, AIVC.
Lubina P: (2004)
“Investigation of a Dynamic Heat Balances in Rooms with Internal Heat
Gains”, Doctor Thesis,
Gliwice
, p 103.
Moskala M: (2004)
“Investigation and Simulation of Air Flows in Dwellings”, Students
Work,
Silesian
Technical
University
,
Gliwice
, p 132.
Nantka
MB
: (1986) “A Study of Air Infiltration and Natural Ventilation in
Dwelling Houses”, Proceedings of International ASHRAE Symposium,
Fort Worth
Texas
.
Nantka
MB
: (1994) “Estimation of Ventilation Performance from Various Points of
View”, Proceedings of The European Conference,
Lyon
, p10.
Nantka
MB
: (1996) “A Method for Prediction of Air Flows in Multizone
Buildings”, Polish
Academy
of
Science Bulletin
, Warsaw XLII, no.2.
Nantka
MB
: (2002) “Measurements of Airtightness in Rooms and Buildings”,
Scientific Bulletin of Technical University,
Opole
, no.46, pp87-124.
Nantka
MB
: (2004) “Ventilation: Problems or Myths?”, Proceedings of
Ventilation Forum Poznañ, p 48.
Persily AK: (1994) “A
Study of Ventilation and Carbon Dioxide in Office Buildings”, ASHRAE
Transactions, Vol.100.
Potter IN:
(1999) “Envelope Integrity Demonstration Study”, Building Services
Research and Information Association,
Old Bracknell Lane West
, ISBN 0 86022-37-2.
Walton GN: (1995)
“Contam – User manual”, National Institute of Standards and
Technology-5385,
Gaithersburg
,
MD.
|
IJV Volume 4 No 1
Contents
Paper
1: Operating Rooms
Paper
2: Field Measurement
Paper
3: Flow Reversal
Paper
4: Thermal Comfort
Paper
5: Urban Buildings
Paper
6: Schools Acoustics
Paper
7: Field Study
Paper
8: Case Study
|
