1 | Building America Program www.buildingamerica.gov
Buildings Technologies Program
Date: November 11, 2011
Opportunities to Apply Phase Change Materials to Building Enclosures
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1 | Building America Program www.buildingamerica.gov
Building America: Introduction
November 11, 2011
Chuck Booten
Building Technologies Program
2 | Building America Program www.buildingamerica.gov
• Reduce energy use in new and existing residential buildings
• Promote building science and systems engineering /
integration approach
• “Do no harm”: Ensure safety, health and durability are
maintained or improved
• Accelerate adoption of high performance technologies
www.buildingamerica.gov
Introduction to Building America
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Building America Industry Consortia
Industry Research Teams
Habitat Cost Effective Energy Retrofit Program
NorthernSTAR Building America Partnership
Building Energy Efficient Homes for America (BeeHa)
4 | Building America Program www.buildingamerica.gov
Today’s Speaker
Dr. Kosny, winner of a 2009 R&D 100 Award for the development of phase-
change materials (PCMs), is a leading building envelope researcher with 30 years
experiences in the building sciences. Dr. Kosny holds a Ph.D. in Building Physics
from the Polish Academy of Sciences. His doctoral research was in area of
passive solar systems. Prior to joining Fraunhofer CSE, Dr. Kosny spent 12 years
teaching building science as a professor of the Rzeszow Technical University,
Poland and 18 years at Oak Ridge National Laboratory. While working for ORNL,
he developed a number of high-performance envelope concepts including
masonry systems, advanced roofing systems, light-gage steel framing and metal-
foam sandwich technologies. He has held a number of faculty positions,
published more than 120 technical articles, and has authored numerous patents
related to advanced building concepts. He has represented the United States at
many international organizations and standards bodies, including the
International Energy Agency. He has extensive experience collaborating with
industry to commercialize advanced building technologies. Particularly relevant to
the proposed presentation, he has worked with most major world manufacturers
of PCM technologies to develop novel dynamic building envelopes based on
integration of advanced heat storage components, local ventilation strategies,
and high-performance insulations (including aerogels, vacuum insulations,
reflective insulations, cool coatings, etc.).
© Fraunhofer USA 2009
Fraunhofer Center for Sustainable Energy Systems
Opportunities to Apply Phase Change
Materials to Building Enclosures
Jan Kosny Ph.D.
Building Enclosure Program
Lead
November 11, 2011
Cambridge, MA USA
[email protected] ph: 865-607-6962
© Fraunhofer USA 2009
Agenda
Introduction – A need for proper performance data for PCMs used in building applications - List of Motivations
2011 update on the Frasunhofer CSE PCM research
Challenges of DSC testing and computer simulations
New Dynamic testing methods and New Performance Label for PCMs
Dynamic testing with use of Heat Flow Meter Apparatus
Potential new ASTM and ISO standards for Dynamic Thermal Testing of non-uniform PCM-enhanced products
2
First successful application of PCMs in
buildings
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
MOTIVATION (I): Performance Problems of
Conventional Insulations
3 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Title_date
Energy consumption change GJ/year
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
6 to 10
10 to
14
14 to
18
18 to
22
22 to
26
26 to
30
30 to
34
34 to
38
38 to
42
42 to
46
46 to
50
50 to
54
54 to
58
Atlanta Bakersfield Chicago Denver
Houston Knoxville Miami Minneapolis
Phoenix Seattle Washington DC
X starting attic R-value
X
R-4
GJ/y
ear
Conventional insulations work only effectively for low R-value
assemblies
ITCC - June 26 - 30, 2011 IEA Annex 24/42 – Sept. 20 - 21, 2011 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
MOTIVATION (II): Different Tactics – Different PCM
Configurations
5 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
European Approach – PCM-Impregnated Gypsum Board
PCM charged by
interior
temperature
swings and solar
gains through
glazing
Building HVAC
system used to
discharge PCM
Schematic of Distribution of Heating and
Cooling Loads in Old PCM Applications
Energy Discharged Later
by HVAC System
Cavity
Insulation
PCM-Gypsum Board
Exterior Finish
Exterior
Interior
Peak Loads
Energy Transferred INTO the Building
Energy Transferred Back
to the Environment
Solar Gains
© Fraunhofer USA 2009
Main Problem with Application of PCM Gypsum Boards in
the U.S. Air-Conditioned Buildings
Enthalpy for commonly-used paraffinic PCM
-45
-30
-15
0
15
30
45
16 17 18 19 20 21 22 23 24 25 26
TEMPERATURE [C]
[J/g
]
melting freezing
Thermostat temperature control +/-2degF
Enthalpy of commonly-used organic PCM
© Fraunhofer USA 2009
New Approach for PCM Installations In the U.S.
Use fluctuations in
exterior temperature
and solar irradiation
for charging and
discharging of PCM
PCM material has to
be able to fully
charge and
discharge energy
during 24-hour
dynamic cycle
Schematic of Distribution of Heating and Cooling
Loads in PCM-Enhanced Bldg. Envelopes
November 11, 2011 Cambridge, MA, USA
Peak Hour Energy Transferred
Back to the Environment
Thermally
Active Core
LOW HEAT
TRANSFER
ZONE
Gypsum Board
Low Delta T Min. Heat Transfer
Exterior Finish
Exterior
Interior
Peak Loads
Thermal insulation
© Fraunhofer USA 2009
Effectiveness of PCMs in cooling attic applications is well
documented (modeling and field testing results)
-0.50
-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
6 12 18 24 30 36 42
time [h]
Btu
/ft2
-h
R-50 roof shingle R-100 roof shingle
R-5deck R-50 PCM R-5deck R-50
Two summer days
R-50
R-5 PCM
18.5 BTU
per ft2
R-50
R-5
R-50
R-100
Attic generated cooling loads
© Fraunhofer USA 2009
Effectiveness of PCMs in cooling attic applications is well
documented (full-scale field testing – MCA project)
2010 cooling season
65% - of # days with
PCM cycling
50% - of total cooling
load reduction
Over 90% - cooling
peak-hour load reduction
0
1
2
3
4
5
6
7
8
04
.02
.10
04
.09
.10
04
.16
.10
04
.23
.10
04
.30
.10
05
.07
.10
05
.14
.10
05
.21
.10
05
.28
.10
06
.04
.10
06
.11
.10
06
.18
.10
06
.25
.10
07
.02
.10
07
.09
.10
07
.16
.10
07
.23
.10
07
.30
.10
08
.06
.10
08
.13
.10
08
.20
.10
08
.27
.10
09
.03
.10
09
.10
.10
09
.17
.10
09
.24
.10
10
.01
.10
10
.08
.10
top melting/bottom frozen all layers cycling top freezing/bottom melted
# of days with PCM cycling
© Fraunhofer USA 2009
Effectiveness of PCMs in cooling attic applications is well
documented (Fraunhofer CSE full-scale test hut testing in New Mexico climate)
Full-scale testing performed for different manufactures of
building materials
General results for 2011:
Roofs: up to 60% cooling load reduction
comparing to traditional roof and attic designs
Walls: up to 50% cooling load reduction
comparing to traditional 2x4 wall assembly
© Fraunhofer USA 2009
2011 update of the Fraunhofer CSE PCM-database
12 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Company Location Product
amount
Temp. Range (°C)
Raw
Data
Downloaded
Flyers
Testing
Method
Micro. Labs USA 17 -30~52 Yes (5) 16 DSC
PCES USA 4 23~29 Yes (4) No DSC
BASF Germany/
USA
9 21~26 Yes (1) 6 DSC
PCM UK 127 -114~885 No 5 tables -
RGEES USA 16 -27~88 Yes (16) 16 T-history
PLUSS India 18 -37~89 No 1 table T-history
(In)
ESI USA 32 -37~151 Yes (8) 1 table DSC
Climator Sweden 11 -21~70 No 11 -
JCXT China 18 5~110 No No -
SGL Germany/
USA
4 22~58°C DSC
Rubitherm Germany 49 -10~86°C No 3-layer
Calorimeter
Capzo Netherlands
Over 350 PCMs represented
© Fraunhofer USA 2009
1. Microtek Laboratories, Inc. (Micro. Labs)
Application: To maintain a regulated temperature
within a product such as textiles, building materials,
packaging, and electronic.
Types of encapsulated PCMs: MicroPCM’s,
MacroPCM’s, Ignition Resilient PCM’s,
Formaldehyde-free PCM’s, Custom PCM products
(Properties could be checked on the website)
Example of data input for a single PCM manufacture
© Fraunhofer USA 2009
Micro. Labs product list
MPCM28
Raw experiment data
MPCM18-D
MPCM37
MPCM42
MPCM52
Website Info
MPCM (-30)
MPCM (-30)D
MPCM (-10)
MPCM (-10)D
MPCM 6
MPCM 6D
MPCM 18
MPCM 18D
MPCM 28
MPCM 28D
MPCM 37
MPCM 37D
MPCM 43
MPCM 43D
MPCM 52
MPCM 52D
Microtek Laboratories, Inc. (Micro. Labs)
© Fraunhofer USA 2009
Microtek Laboratories, Inc. (Micro. Labs)
© Fraunhofer USA 2009
Microtek Laboratories, Inc. (Micro. Labs)
Basic Info Sample name MPCM28
Appearance (Form) White to slightly off-white color (Wet
cake)
Chemical components n-Octadecane
Organic/Inorganic Organic
Test Data Test method PerkinElmer Thermal Analysis (DSC)
Temp. change rate 5°C/min
Sample mass 2.100 mg
Melting Temp. 29.514°C
Freezing Temp. 23.843°C
Subcooling range 5.671°C
Melting overall enthalpy 164.204 kJ/kg
Freezing overall enthalpy 108.634 kJ/kg
Melting Temp. range 17.4°C~33.8°C
Freezing Temp. range 26.1°C~19.1°C
© Fraunhofer USA 2009
Challenges of DSC testing and computer simulations
18 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Large Selection of Non-Uniform PCMs is in common
use today which cannot be tested in DSC
PCM blend
© Fraunhofer USA 2009
Key Temperatures of the PCM Transition Process
Enthalpy for commonly-used paraffinic PCM
-45
-30
-15
0
15
30
45
16 17 18 19 20 21 22 23 24 25 26
TEMPERATURE [C]
[J/g
]
melting freezing
Temperature Range of Phase
Change Process
Lower
Temperature
Limit
Upper
Temperature
Limit
© Fraunhofer USA 2009
Example of estimation of temperature ranges for DHMA
test using H(T) chart for a blend of thermal insulation and
microencapsulated PCM.
21 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
0.0E+00
1.0E+05
2.0E+05
3.0E+05
4.0E+05
5.0E+05
6.0E+05
7.0E+05
8.0E+05
9.0E+05
1.0E+06
1.1E+06
-5 0 5 10 15 20 25 30 35 40 45 50 55
De
lta
en
tha
lpy J
/m^
2
Temperature, C
Delta enthalpy for PCM board J/m^2
DSC can be very useful in solving surprising situations
22 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Advantages of Symmetrical Testing Processes
Transient effects on both plates of HFMA are identical
Since temperature profile is always symmetrical during
the experiment, it is possible to analytically estimate and
later subtract mass-related effects on both plates
Measurement errors generated by heat flux transducers
and heat diffusion time lags are identical on both plates
It is possible to subtract measurement errors generated
by heat flux transducers (due to dynamic character of the
test)
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
A standard testing HFMA equipment can be modified to
allow dynamic testing of PCM-enhanced products.
Normally the HFMAs are used to measure the apparent thermal
conductivity of materials as specified in ASTM C518.
12
17
22
27
32
37
42
47
0 20 40 60 80
Time [min]
Te
mp
era
ture
[d
eg
C]
bottom plate
upper plate
43oC
16oC
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Major Challenges
Potential misinterpretation of
the enthalpy test data in
computer simulations
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Major Challenges
Most of currently used whole
building energy simulation
models do not properly
represent PCM thermal
characteristics
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Rate of Temperature Change Effects Enthalpy Profiles
Incorrect DSC data is very often used in whole building
computer simulations
27
DSC Melting DSC Freezing
Temp. deg CTemp. deg CJ/
Kg
K
J/K
gK
Heating rate Heating rate
Lower temperature limit of PCM freezing range
Upper temperature limit of PCM melting range
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
PCM subcooling effect is not properly represented
Estimation of upper and lower temperature limits for sample of the PCM-
enhanced material or composites using original DSC test data for PCM (paraffinic
PCM data shown).
28 November 11, 2011 Cambridge, MA, USA
-10,000.00
-8,000.00
-6,000.00
-4,000.00
-2,000.00
0.00
2,000.00
4,000.00
6,000.00
8,000.00
10,000.00
-6.0
0
-4.0
0
-2.0
0
0.0
0
2.0
0
4.0
0
6.0
0
8.0
0
10
.00
12
.00
14
.00
16
.00
18
.00
20
.00
22
.00
24
.00
26
.00
28
.00
30
.00
32
.00
34
.00
36
.00
38
.00
40
.00
42
.00
DSC uW
24.0 oC (75.2 oF) 27.2 oC (81.0 oF)
24.0 oC (75.2 oF)
25.7 oC (78.3 oF) 31.8 oC (89.2 oF)
32.0
0
50
.00
68
.00
86
.00
10
4.0
0
oF
Phase transition range
© Fraunhofer USA 2009
Need for Development of Enthalpy Charts for PCM-
Enhanced Materials and Systems
Initial Differential Scanning Calorimeter (DSC) tests for pure PCMs or PCM microcapsules, only
Additions to PCM-based blends make a difference; Dynamic Heat Flow Meter Apparatus tests were introduced in 2006 for PCM-enhanced insulations - fire retardant effect, adhesives, not-working PCM pellets, etc….
0.00
2.00
4.00
6.00
8.00
10.00
12.00
16.00 18.00 20.00 22.00 24.00 26.00 28.00
Temp [deg C]
J/g
DSC 80% 67%
© Fraunhofer USA 2009
Dynamic Test Methods Used in Analysis of PCMs and
PCM-Enhanced Products
DSC – only for uniform PCMs
T-history method
Dynamic Heat Flow Apparatus Method
• Symmetrical process
• Non-symmetrical process
Dynamic Guarded Hot-Plate Method – only speculations so far
Dynamic Hot-Box Method
30 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Complex arrays of PCM containers are extremely difficult
to test in conventional HFMA equipment Example of estimation of the measure area for the arrays of PCM
pouches or PCM containers.
Measure AreaMeasure Area
Measure area needs to contain representative
geometry of the measured array of PCM containers
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Potential area for misuse of the experimental data on PCM-
enhanced products for most-likely marketing purposes
32 ITCC - June 26 - 30, 2011
Enthalpy for commonly-used paraffinic PCM
-45
-30
-15
0
15
30
45
16 17 18 19 20 21 22 23 24 25 26
TEMPERATURE [C]
[J/g
]
melting freezing
For what temperature range PCM enthalpy should be calculated if cp-related
effects are included together with phase transition–related effects?
This
one?
Or, this one ???
© Fraunhofer USA 2009
M-value – New Energy Performance Label for PCM-
Enhanced Products Expressing only phase transition-related enthalpy change
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Understanding of Enthalpy Profile in estimation of M-value
H
Temp.
It is possible to analytically estimate and later subtract cp-related enthalpy
changes for both frozen and melted stages of the testing.
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Basic Heat Transport Equations:
The one-dimensional heat transport equation for such a case is as follows:
where; ρ and λ are the material density and thermal conductivity, T and h are temperature and enthalpy per unit mass. Heat flux q is given by:
The enthalpy derivative over the temperature (with consideration of constant pressure) represents the effective heat capacity, with phase change energy being one of the components:
Effective heat capacity, ceff, for a material which is a blend of insulation and PCM may be expressed as
where α denotes the percentage of PCM, cins the specific heat of insulation without PCM and ceffPCM is effective heat capacity of PCM.
Th
t x x
,,
T x tq x t
x
eff
hc T
T
1eff ins effPCMc c c
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Practical determination of M-value based on the DHFMA data
0.0E+00
2.0E+05
4.0E+05
6.0E+05
8.0E+05
1.0E+06
1.2E+06
1.4E+06
1.6E+06
1.8E+06
2.0E+06
2.2E+06
2.4E+06
2.6E+06
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Vo
lum
etr
ic s
pe
cif
ic h
ea
t, J
/(m
^3
K)
Temperature, C
Volumetric Heat Capacity A
Volumetric Heat Capacity B
Volumetric Heat Capacity C
cp related change for
frozen PCM
cp related change
for melted PCM
Phase
transition
range
Subtract cp
related
change for
melted PCM
Subtract cp
related
change for
frozen PCM
>5%
enthalpy
change per
temperature
step
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Final Result
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Example of Dynamic Heat Flow Metter Apparatus
Testing of Loose-Fill Insulations Mixed with
Microencapsulated PCM
38 November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Enthalpy change profiles for 2oC temperature steps
39
0.0E+00
1.0E+06
2.0E+06
3.0E+06
4.0E+06
5.0E+06
6.0E+06
7.0E+06
4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
Vo
lum
etr
ic H
Pro
file
, J/(
m3)
Temperature, C
Volumetric H (A)
Volumetric H (B)
Volumetric H (C)
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
0.0E+00
2.0E+05
4.0E+05
6.0E+05
8.0E+05
1.0E+06
1.2E+06
1.4E+06
1.6E+06
1.8E+06
2.0E+06
2.2E+06
2.4E+06
2.6E+06
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Vo
lum
etr
ic s
pe
cif
ic h
ea
t, J
/(m
^3
K)
Temperature, C
Volumetric Heat Capacity A
Volumetric Heat Capacity B
Volumetric Heat Capacity C
Final Test Results
40
Described above measurements yielded the total enthalpy of the tested PCM-enhanced
material of 16.25 J/g, with a +/-3.4% difference between the highest and lowest results.
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009
Future Fraunhofer CSE Work
Addition of new PCMs to the database
Addition of new PCM-enhanced products???
Introduction of the uniform performance label for PCMs
Dynamic testing of more material samples
Whenever it is possible compare DHFMA data with DSC or T-history test data
More testing with different temperature steps
Modeling leading to optimization of the temperature step – as a function of specimens thermal conductivity and thickness
Field testing of PCM systems
Development of the ASTM and ISO standards
November 11, 2011 Cambridge, MA, USA
© Fraunhofer USA 2009 ITCC - June 26 - 30, 2011 [email protected] ph: 865-607-6962
1 | Building America Program www.buildingamerica.gov
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