Part 1 Transferring energy between 2 building zones Nordic PhD Seminar 08 12 2011 1 Jérôme LE DRÉAU 2 Jérôme Le Dréau jldcivilaaudk ID: 584545
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Slide1
Investigation of energy flows in thermally activated building constructions Part 1: Transferring energy between 2 building zones
Nordic PhD Seminar08 / 12 / 2011
1
Jérôme LE DRÉAUSlide2
2Jérôme Le Dréau jld@civil.aau.dk
Transfer between zonesRadiant cooling
Transferring energy between
two
building zones
Heating the North side
Winter
or cloudy days
Summer
or sunny days
Cooling the South side
Transferring energy between 2 building zonesSlide3
3
Presentation of
the system:
capillary tube mats
Wall
Very large-area heat
exchangers
Low temperature difference can be used
Small
time constant
Capillary
tube
System used
for
heating
System used
for cooling
Thanks to a smart
hydraulic layout
, possibility of transferring energy between the 2 rooms
Transfer between zones
Radiant cooling
Transferring energy between
two
building zonesSlide4
4Jérôme Le Dréau jld@civil.aau.dk
Results:
Transfer between zones
Radiant cooling
Transferring energy between
two
building zonesSlide5
5
Jérôme LE DRÉAU
Investigation of energy flows in thermally activated building constructions
Part 2:
Cooled radiant walls coupled to the room environment
Nordic PhD Seminar
08 / 12 / 2011Slide6
6Cooled radiant walls coupled to the room environment
Hypothesis:
Cooled radiant walls will remove
the
heat more efficiently than an air conditioning system.
Energy
Indoor climate
Transfer between zones
Radiant cooling
The different solutions will be compared,
combining
the analysis of two parameters:
Energy consumption (quantity & quality of the source)
Comfort in the room (quality of the energy delivered)
Finally
how to define
efficiency…Slide7
7Cooled radiant walls coupled to the room environment
Methods used:
Simulations (CFD + simulation of energy systems)
Full-scale experiments
Transfer between zones
Radiant cooling
Contents :
How to evaluate the energy consumption?
How to evaluate the indoor climate
?
First
resultsSlide8
8Cooled radiant walls coupled to the room environmentHow to evaluate the energy consumption?
Transfer between zones
Radiant coolingSlide9
9
Cooled radiant panel:
Cooled radiant walls coupled to the room environment
Transfer between zones
Radiant cooling
Wall
Very large-area heat
exchangers
Low temperature difference can be used
Small
time constant
Capillary
tubeSlide10
10
Different ventilation types:
Mixing ventilation
(different types)
Displacement ventilation
Cooled radiant walls coupled to the room environment
Transfer between zones
Radiant coolingSlide11
11
What happens in the room?
Cooled radiant walls coupled to the room environment
% Radiant panel
%
Radiation
%
Convection
% Transmission
% Ventilation
Mini
25%
50%
75%
100%
Transfer between zones
Radiant cooling
Result:
heat balance of the roomSlide12
12Cooled radiant walls coupled to the room environment
Result:
energy consumption of the room
With or without cooling
ACH ->
Q
fans
T
inlet
Flow rate ->
Q
pumps
T
inlet
Transfer between zones
Radiant cooling
Different control strategies: high flow rates OR low inlet temperatureSlide13
13Cooled radiant walls coupled to the room environment
Source 1:
Outdoor air
BUILDING
Transfer between zones
Radiant cooling
Result:
energy consumption of the building & quality of energy
Source 2:
Groundwater
Source 3:
Sky radiation
Source 4:
…
Storage tankSlide14
14Cooled radiant walls coupled to the room environmentHow to evaluate the indoor climate?
Transfer between zones
Radiant coolingSlide15
15
Air temperature
Radiant
temperature
Air
velocity
Cooled radiant walls coupled to the room environment
EN ISO 7730
PMV Additional parameters
Vertical
air temperature
gradient
Radiant
temperature
asymmetry
Surface temperatures
Draught
rating
Indoor Air Quality
Transfer between zones
Radiant coolingSlide16
16Cooled radiant walls coupled to the room environmentFirst results
Transfer between zones
Radiant coolingSlide17
17
Model used:
Cooled radiant walls coupled to the room environment
Transfer between zones
Radiant cooling
Heating case
Outdoor temperature of -12°C
Construction parts (BR10):
External wall: U=0.15W/m
2
.K
Window: U=1.40W/m
2
.K
Roof: U=0.10W/m
2
.K
Ground: no heat losses
Different
ventilation rates (0.5ACH – 3ACH)
100
% convective OR 100%
radiative (floor)
No air temperature gradient OR Air temperature gradientSlide18
18Cooled radiant walls coupled to the room environment
Transfer between zones
Radiant cooling
Static calculation with heating power kept constant
Results:Slide19
19
Results:
Cooled radiant walls coupled to the room environment
Transfer between zones
Radiant cooling
ACH
Heating power (W)
0.5
500
1.5
900
2
1100
3
1500Slide20
Thank you for your attention!20
Jérôme LE DRÉAU
PhD fellow
Supervisor: Prof. Per HEISELBERG
Aalborg University (DK) - Department of Civil Engineering
@
jld@civil.aau.dk
+45 50 30 01 37
Radiant wall coupled to the room environment
Transfer between zones
Radiant cooling