ASTM E576-14(2020)
(Test Method)Standard Test Method for Frost/Dew Point of Sealed Insulating Glass Units in the Vertical Position
Standard Test Method for Frost/Dew Point of Sealed Insulating Glass Units in the Vertical Position
SIGNIFICANCE AND USE
5.1 This test method is suitable for use under actual or simulated in-service conditions; that is, one side of the unit is exposed to room temperature, while the other side is exposed to natural or simulated weather conditions. Where the glazing conditions and the 24 h history are different or changed from previous conditions, the frost/dew point may not be comparable to a previous measurement.
5.2 This test method is applicable for the uncoated or unfilmed clear (transparent) glass lite of sealed insulating glass units. If this apparatus is used with coated or filmed glass lite, the coating or film on the surface of glass lite may be damaged.
5.3 This test method may require minor modifications to keep the measuring surface of the frost/dew-point apparatus in contact with the glass if the insulating glass unit is not in the true vertical position.
SCOPE
1.1 This test method describes a field or laboratory procedure for determining the frost/dew point within the air space(s) of sealed insulating glass units and establishes the criteria for determining whether that point is below or above a given or specified temperature.
1.2 This test method also describes the apparatus to be used for these determinations.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 9.1.3 and 9.3.8.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E576 − 14 (Reapproved 2020)
Standard Test Method for
Frost/Dew Point of Sealed Insulating Glass Units in the
Vertical Position
This standard is issued under the fixed designation E576; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope E77Test Method for Inspection and Verification of Ther-
mometers
1.1 This test method describes a field or laboratory proce-
E631Terminology of Building Constructions
durefordeterminingthefrost/dewpointwithintheairspace(s)
E774Specification for the Classification of the Durability of
of sealed insulating glass units and establishes the criteria for
Sealed Insulating Glass Units (Withdrawn 2006)
determining whether that point is below or above a given or
specified temperature.
3. Terminology
1.2 This test method also describes the apparatus to be used
3.1 Definitions—Fordefinitionsofgeneraltermsusedinthis
for these determinations.
test method, refer to Terminology E631.
1.3 The values stated in inch-pound units are to be regarded
3.2 Definitions of Terms Specific to This Standard:
as standard. The values given in parentheses are mathematical
3.2.1 frost/dew point—the temperature at which water, or-
conversions to SI units that are provided for information only
ganic vapor, or other chemicals begin to appear on the interior
and are not considered standard.
glass surface of a sealed insulating glass unit in contact with
1.4 This standard does not purport to address all of the the measuring surface of the frost/dew-point apparatus.
safety concerns, if any, associated with its use. It is the
3.2.2 frost state—the case where the frost/dew point of a
responsibility of the user of this standard to establish appro-
sealed insulating glass unit is above the test temperature
priate safety, health, and environmental practices and deter-
specified by the purchaser or user.
mine the applicability of regulatory limitations prior to use.
3.2.3 no-frost state—the case where the frost/dew point of a
For specific hazard statements, see 9.1.3 and 9.3.8.
sealed insulating glass unit is below the temperature specified
1.5 This international standard was developed in accor-
by the purchaser or user.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Summary of Test Method
Development of International Standards, Guides and Recom-
4.1 This test method is conducted by the use of a special
mendations issued by the World Trade Organization Technical
apparatus, consisting basically of two chilled cylindrical metal
Barriers to Trade (TBT) Committee.
blocks positioned one over the other and separated by a gap of
controllable distance. The upper block has an exposed flat
2. Referenced Documents
circular surface, 1 in. (25 mm) in diameter, and can be chilled
2.1 ASTM Standards:
to far below the ice point by regulating the air gap distance
C1036Specification for Flat Glass
between it and the lower metal block which is maintained at
approximately −109°F (−78°C) by dry ice.The test specimen
This test method is under the jurisdiction of ASTM Committee E06 on is placed in contact with this chilled flat circular surface of the
Performance of Buildings and is the direct responsibility of Subcommittee E06.22
upper block for specified short periods of time, with the metal
on Durability Performance of Building Constructions.
surface at successively lower temperatures, to determine at
Current edition approved May 1, 2020. Published May 2020. Originally
what temperature frost appears on the corresponding lower air
approved in 1976. Last previous edition approved in 2014 as E576–14. DOI:
10.1520/E0576-14R20.
space glass surface.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E576 − 14 (2020)
Parts List
Part No. Nomenclature Part No. Nomenclature
1 front metal block 12 supporting ring, bottom of
inner tube
2 rear metal block 13 control ring
3 top cover 14 cover lid, inner tube
4 supporting plate, front metal 15 elbow
block
5 spacer 16 tube, nylon
6 spring front metal block 17 main spring
7 supporting plate, top of 18 spacer
inner tube
8 outer tube 19 bearing
9 inner tube 20 bimetallic dial thermometer
10 disk, dry ice pushing 21 dial indicator
11 clamp, dial gage 22 heat source block
FIG. 1 Schematic Diagram of Frost/Dew-Point Apparatus
5. Significance and Use 6. Apparatus
5.1 This test method is suitable for use under actual or 6.1 Test Apparatus (see Fig. 1); consisting of upper and
simulated in-service conditions; that is, one side of the unit is lower cylindrical metal blocks with a thermocouple, bimetallic
exposed to room temperature, while the other side is exposed thermometer, or other suitable temperature sensors being
to natural or simulated weather conditions. Where the glazing inserted in the upper block; a control ring; and an insulated
conditions and the 24 h history are different or changed from containment cylinder fitted with a retainer spring assembly.
previous conditions, the frost/dew point may not be compa- The two metal blocks are separated by a small air gap, the
rable to a previous measurement. distance of which can be regulated by the control ring. The
exposedflatcircularsurfaceoftheupperblockis1in.(25mm)
5.2 This test method is applicable for the uncoated or
in diameter, has a ground or lapped finish, and when placed in
unfilmedclear(transparent)glassliteofsealedinsulatingglass
units. If this apparatus is used with coated or filmed glass lite,
thecoatingorfilmonthesurfaceofglasslitemaybedamaged.
The sole source of supply of the apparatus known to the committee at this time
is Dennis Industries, 20032 Waynegarden Court, Germantown, MD 20874, http://
5.3 This test method may require minor modifications to
www.dennisind.com. If you are aware of alternative suppliers, please provide this
keep the measuring surface of the frost/dew-point apparatus in
information to ASTM International Headquarters. Your comments will receive
contact with the glass if the insulating glass unit is not in the
careful consideration at a meeting of the responsible technical committee, which
true vertical position. you may attend.
E576 − 14 (2020)
contact with the glass test specimen, forms the frost/dew point 6.2 Vertical Attachment Fixture (seeFig.2),consistingofa
measuringsurface.Thelowerblockischilledbyadryicepack twin-grip vacuum cup holder, two parallel guide rods, two
kept in contact with it by the retainer spring assembly, spring posts, and two clamping springs. The vacuum cup is
maintaining it at a temperature near to that of sublimating dry made of rubber. When the vertical attachment fixture is placed
ice (−109°F (−78°C)). Because the solid metal blocks are on the surface of clean glass and the vacuum hand lever is
highlyconductive,thetemperatureofeachisvirtuallyuniform. pushed down, the vertical attachment fixture becomes firmly
Useofthecontrolringadjuststheairgapdistancebetweenthe attached to the glass surface. Other equivalent attachment
two blocks to give the desired thermal resistance across the air fixtures may be used.
gap. The circular measuring surface of the upper block is thus
6.3 Glass Thickness Gage (see Fig. 3).
readily adjusted to the desired temperature while in contact
with the test specimen. The circular measuring surface diam- 7. Test Unit
eter specified is suitable for frost/dew point measurement of
7.1 The sealed insulating glass unit to be tested should have
glass up to ⁄4 in. (6.0 mm) thick.
aclearglasslite(see5.2)incontactwiththemeasuringsideof
6.1.1 Upper and Lower Blocks,aluminumalloythatmaybe
the test apparatus and shall be positioned vertically.
anodized,conformingtothedimensionsshowninFig.1.Other
parts of the apparatus may be fabricated from any appropriate 8. Conditioning
materials.
8.1 Condition the unit to be tested at room temperature on
6.1.2 Calibrated Temperature-Measuring Device; such as a
both unit sides by exposing to a temperature of 75°F 65°F
thermocouple, thermistor, or bimetallic thermometer; having a
(24°C 63°C) for not less than 24 h prior to the testing.
suitablerangegraduatedin2°F(1°C)orsmallerunits;andan
8.2 Condition the unit to be tested under simulated in-
accuracy of 61°F(60.5°C) over the full scale. A suggested
service conditions by exposing to temperatures within 65°F
calibration of the bimetallic thermometer is described in
(63°C) of the desired simulated conditions for not less than
Appendix X1.
24h prior to testing.
6.1.3 The size of the temperature measuring probe shall
match the bore size drilled into the aluminum head in order to 8.3 For the unit to be tested under actual in-service
ensure proper temperature measurements. conditions, record or obtain the ambient temperatures of both
Parts List
Part No. Nomenclature
1 rubber vacuum cup
2 guide rod
3 clamping spring
4 vacuum hand lever
5 hand grip
6 spring post
FIG. 2 Vertical Attachment
E576 − 14 (2020)
(a) Gage (b) Gage in Use
FIG. 3 Glass Thickness Gage
sides of the unit at the start and end of a particular measuring 9.3.2.1 Place the long side of the glass thickness gage (see
period, and the 24 h temperature history prior to testing. Fig. 3) against the glass pane at a 45° angle.
9.3.2.2 Observe the reflection in the glass.
NOTE 1—At the present time, there is insufficient information to
9.3.2.3 Note where the long line superimposes the short
compare the measured frost/dew point of the unit from the reported
temperature history to that implied in-service level of the unit. However,
line.
the temperature history will provide a valuable basis for evaluating the
9.3.2.4 Read the minimum thickness of the glass above.
in-service level and life of the unit in the future.
9.3.3 Placethefrost/dew-pointapparatusontopoftheguide
rods of the vertical attachment fixture, facing the measuring
9. Procedure
surface of the frost/dew-point apparatus toward the rubber
9.1 Preparation of Frost/Dew-Point Apparatus:
vacuum cup, and slide both guide fins of the frost/dew-point
9.1.1 Disassemble the apparatus by removing the dry ice
apparatus in between the guide rods from the rear end.
container and retainer spring assembly. Carefully clean the
9.3.4 Hook each clamping spring to the hooks of the
measuringsurfacewithasoftclothorpaper.Donotscratchthe
frost/dew-point apparatus.
measuring surface.Wipe and clean the apparatus thoroughly if
9.3.5 Clean the exterior glass surface where the frost/dew-
any moisture has condensed on the surfaces and walls.
point apparatus and the vertical attachment fixtures are to be
9.1.2 Assemble the dry ice container and turn the control
placed. Measure the frost/dew point within an area at least 10
ring so that the air gap distance between front and rear metal
in. (250 mm) away from the spacer or at the center of the unit.
blocksisabout0.5in.(13mm).Inverttheapparatusontoasoft
Examine the interior air space glass surface in the region,
cloth or a suitable mounting bracket.
where dew or frost is to be deposited, to be aware of any dirt
9.1.3 Spray alcohol or acetone (Warning—Both alcohol
or other foreign particles that might be mistaken for frost.
and acetone are flammable.) on the fin of the dry ice container
However,asmallforeignparticleontheinteriorairspaceglass
to ensure good contact with the dry ice. Compactly charge the
surface may be helpful in focusing on the surface where the
containerwiththecrushedorpulverizeddryiceuptothe“full”
frost is to be deposited. Avoid the area where sunlight strikes
mark. Compress the dry ice with the spring assembly and lock
directly on the unit or shade it from direct sunlight.
the cover lid.
9.3.6 Release both vacuum hand levers of the vertical
9.1.4 Turn the apparatus to an upright position. Allow
attachment fixture.
sufficient time for the temperature of the rear metal block to
9.3.7 Due to the changes in the cold plate design, the use of
approach near that of the dry ice temperature.
the aluminized polyester film is no longer a requirement.
9.2 Recharging of Frost/Dew-Point Apparatus—During the
However, it is still recommended in order to ensure a pristine
test procedure, replenish the supply of dry ice whenever it
viewing surface. If the reflective film is used then use the
becomes depleted by inverting the apparatus onto a soft cloth,
following procedure:
opening the cover lid, taking out the retainer spring assembly,
9.3.8 Clean the surfaces of the rubber vacuum cups, and the
and repeating steps 9.1.3 and 9.1.4.
measuring surface and front surface of the frost/dew-point
9.3 Determination of Frost State or No-Frost State: apparatus. If there are any water vapor or frost deposits on the
9.3.1 Charge the frost/dew-point apparatus with dry ice as measuring surface of the frost/dew-point apparatus, clean the
described in 9.1 or 9.2. measuring surface by wetting with alcohol (Warning—
9.3.2 Measure the thickness of glass in the measuring side Alcohol is flammable.). If the measuring surface is heavily
as follows: scratched,thefrontmetalblockshouldbereplacedorrepaired.
E576 − 14 (2020)
If the dew or frost deposit can be checked from the other side shim the guide rod. (Warning—Take care that the vertical
of the unit as described in 9.3.16, a piece of silver-colored attachment fixture does not fall off during the measurement.)
aluminized polyester film with a highly reflective surface, not 9.3.12 Wipe off the excessive alcohol running down the
thicker than 0.003 in. (0.08 mm), and 1 in. (25 mm) in glass surface from the measuring surface before it reaches the
diameter, or 1in. by 1 in. (25mm by 25 mm) can be placed on glazing materials.
the measuring surface by wetting both surfaces with alcohol. 9.3.13 Slowlyreducetheairgapdistancebetweenfrontand
9.3.9 To provide better thermal contact, wet the measuring rear metal blocks by tur
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