In-situ and thin-specimen aging of experimental polyisocyanurate roof insulation foamed with alternative blowing agents
This paper reports apparent thermal conductivity (k) values from field and laboratory aging tests on a set of industry-produced, experimental polyisocyanurate (PIR) laminated boardstock foamed with hydrochlorofluorocarbons (HCFCs) as alternatives to chlorofluorocarbon (CFC). The PIR boards were blown with five gases: CFC-11, HCFC-123, HCFC-14lb, and 50/50 and 65/35 blends of HCFC-123/HCFC-14lb. The k-values were determined from 0 to 50{degree}C (30 to 120{degree}F) using techniques that meet ASTM C 114 (Thin Heater Apparatus) and ASTM C 518 (Heat Flow Meter Apparatus). Results on laminate boards with facers provide an independent laboratory check on the increase in k observed for field exposure in the ORNL Roof Thermal Research Apparatus (RTRA). The observed laboratory increase in k was between 8% and 11% for a 240 day field exposure in the RTRA. A thin-specimen aging procedure established the long-term thermal resistance of gas-filled foams. Thin specimens were planed from the industry-produced boardstock foams and aged at 24 and 65{degree}C (75{degree}F and 150{degree}F) for up to 300 days. An exponential dependency of k with the quantity (diffusion coefficient X time){sup {1/2}}/ thickness, provide effective diffusion coefficients for air components into the foams and blowing agent out of the foams. The foams blown with alternative blowing agents exhibited k-values 3 to 16% (average 9.4%) above CFC-11 foams under similar conditions. Field exposures were conducted on specimens under single ply EPDM membranes in the RTRA for over 400 days. Hourly averages of panel temperature and heat flux were analyzed to obtain K as a function of mean temperature on a week by week basis. The relative performance of test specimens of HCFC-14B under a black and under a white membrane is reported. 29 refs., 10 figs., 10 tabs.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE; USEPA; USDOE, Washington, DC (United States); Environmental Protection Agency, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5647470
- Report Number(s):
- CONF-911038-1; ON: DE91006277
- Resource Relation:
- Conference: 2. symposium on insulation materials: testing and applications, Gatlinburg, TN (United States), 10-12 Oct 1991
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
54 ENVIRONMENTAL SCIENCES
BUILDING MATERIALS
TESTING
CHLORINATED ALIPHATIC HYDROCARBONS
AGING
FLUORINATED ALIPHATIC HYDROCARBONS
ROOFS
THERMAL INSULATION
THERMAL CONDUCTIVITY
EXPERIMENTAL DATA
FIELD TESTS
FOAMS
HEAT FLOW
HEAT FLUX
MATERIAL SUBSTITUTION
MEDIUM TEMPERATURE
COLLOIDS
DATA
DISPERSIONS
HALOGENATED ALIPHATIC HYDROCARBONS
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
320107* - Energy Conservation
Consumption
& Utilization- Building Systems- (1987-)
360603 - Materials- Properties
540120 - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)