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Joanna Polak, Ph.D. candidate
Danish Building Research Institute, Aalborg University, Copenhagen,
Denmark
A NOVEL VENTILATION AND HEATING
SYSTEM FOR RESIDENTIAL BUILDINGS
DANVAK Dagen 2018 April 11, 2018
2
Indoor climate in residential buildings and
importance of ventilation
Indoor air pollutants in residential
buildings can lead to discomfort or may
cause health implications
Pollutants are produced externally or
within the building
Ventilation is a key factor in maintaining
a satisfactory indoor climate for the
occupants
Common sources of indoor air pollution
3
Residential ventilation
Ref. Technical Note AIVC 57: Residential ventilation, 2002
Ref. Danish Building Regulations, 2018
Passive Stack Ventilation Mechanical Extract Balanced Mechanical Ventilation
with Heat Recovery
Transition from traditional ventilation concepts towards mechanical ventilation with
heat recovery
Due to strict energy regulations mechanical ventilation is common a requirement
in residential buildings
4
Combined ventilation and heating systems
Incorporation of heating into ventilation system
Simplified space-heating distribution system, reduction of HVAC system installation
and maintenance costs
Suitable for passive houses, where thermal comfort can be achieved solely by post-
heating of the supply air
Possibility to supply heat via supply air at ventilation rates based on IAQ
requirements with a maximum supply air temperature of about 50°C
Ref. Passive House Institute. 2014. The Passivhaus Standard.
Ref. Feist et al. 2005. Energy and Buildings, 37, 1186-1203.
5
Combined ventilation and heating systems
Limitations related to provision of the desired thermal comfort on room level within a
dwelling
t air
6
Combined ventilation and heating systems
Limitations related to provision of the desired thermal comfort on room level within a
dwelling
t ref
The same supply air temperature t air in all rooms
Regulation in individual room is not possible
t air
7
Combined ventilation and heating systems
Limitations related to provision of the desired thermal comfort on room level within a
dwelling
t ref
The same supply air temperature t air in all rooms
Regulation in individual room is not possible
According to Danish regulations it should be possible adjusted the air temperature on
room level
Ph.D. project
8
Title: A new ventilation system for sustainable residential buildings
Supervisor: Alireza Afshari, professor with specific responsibilities, SBi, AAU
Co-supervisors: Niels Christian Bergsøe, senior researcher, SBi, AAU
Göran Hultmark, development manager, R&D, Lindab A/S; adjunct professor,
SBi, AAU
Objectives: The goal of the project is to design, develop and evaluate the performance of a
novel, temperature-based demand controlled ventilation system. The novelty of
the system is its capability to adjust the supply air flow rate and air
temperature on a room level.
Methodology: Calculations/ Simulations
Experiment in a laboratory
Full-scale test in a real building
9
Regulation on room level
Ref. Polak et al., Development of a novel temperature-based demand controlled ventilation system for residential buildings,
accepted for Indoor Air Conference, 2018
10
Regulation on room level
manifold
Ref. www.lindab.com 11
Supply ductwork
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Laboratory experiment
Experimental setup, Lindab A/S, Farum
Full-scale prototype of the system
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15
20
25
30
35
40
45
50
55
0 15 30 45 60 75 90
Air t
em
pera
ture
, °C
Damper position, °
t1 t2 t3
Control of the air temperature
The temperature of the supply air can be controlled individually in each of the supply
ducts in a range of 25 °C and 52 °C, for the input parameters used in the experiment
Ref. Polak et al., Development of a novel temperature-based demand controlled ventilation system for residential buildings,
accepted for Indoor Air Conference, 2018
14
y = 0,0269x + 0,194R² = 0,9982
y = 0,0649ln(x) + 0,6689R² = 0,6739
0,50
0,55
0,60
0,65
0,70
0,75
0,80
0,85
0,90
0,95
1,00
0,00
0,25
0,50
0,75
1,00
1,25
1,50
1,75
2,00
2,25
2,50
2,75
3,00
0 10 20 30 40 50 60 70 80
Eff
ectiveness,
-
Pow
er
deliv
ere
d in w
ate
r, k
W
Airflow rate, l/s
maximum power delivered in water effectiveness of heat exchange
𝜀 =ሶ𝑄
ሶ𝑄𝑚𝑎𝑥
ሶ𝑄 = ሶ𝑞𝑚,𝑎𝑖𝑟 ∙ ℎ𝑜𝑢𝑡𝑙𝑒𝑡,𝑎𝑖𝑟 − ℎ𝑖𝑛𝑙𝑒𝑡,𝑎𝑖𝑟
ሶ𝑄𝑚𝑎𝑥 = ሶ𝑞𝑚,𝑤𝑎𝑡𝑒𝑟 ∙ ℎ𝑖𝑛𝑙𝑒𝑡,𝑤𝑎𝑡𝑒𝑟 − ℎ𝑜𝑢𝑡𝑙𝑒𝑡,𝑤𝑎𝑡𝑒𝑟
Effectiveness of heat exchange
The effectiveness of heat exchange was defined as a ratio of the actual heat
transfer rate to the maximum possible heat transfer rate and calculated as:
Ref. Polak et al., Development of a novel temperature-based demand controlled ventilation system for residential buildings,
accepted for Indoor Air Conference, 2018
Air flow rate: 14 l/s
Supply air temperature: 37 °C
15
Thermal comfort in a room
16
Further steps
Energy performance Installation in a building
Simulations: Modelica model of the system
