The Right Insulation for Cold Systems

Transcription

1 AP Armaflex The Closed Cell Solution The Right Insulation for Cold Systems PREVENTS MOISTURE INTRUSION AND ITS CONSEQUENCES Ensures long-term thermal performance Inhibits mold and mildew, protects IAQ Withstands abuse no separate vapor retarder to damage AP Armaflex: It s more than just insulating.

2 Why Insulate Cold Systems? Insulation is typically seen as a means to prevent heat gain or loss through the building envelope. Yet energy efficient design must also address all interior piping and air handling systems with the right insulation materials in the right thicknesses. These systems benefit particularly from the right insulation s ability to prevent condensation, moisture intrusion and longer-term problems. Moisture from condensation is a problem in any cold system. Too frequently, it is assumed that all insulations are equally suitable for any insulation application. This generalization is wrong for cold systems and can lead to system failure, call-backs, energy waste, even mold and building closings. Not every insulation is engineered for cold applications. And the perceived convenience of specifying a single insulation material for an entire project can result in costly consequences. Armacell is the global market leader in foams technology. The company invented Armaflex, the world s best known and most trusted trademark in elastomeric foam insulation. AP Armaflex World s MOST SPECIFIED closed cell elastomeric foam for insulating chilled water and refrigeration piping and air handling systems Glossary for Cold Systems Thermal Conductivity The amount of heat (BTU) transferred in one hour through one square foot of a homogeneous material 1-inch thick for a difference in temperature of 1 degree F. The lower the value, the better the insulator. Perm A measure of vapor-transmission rate. Defined as 1 grain of water vapor per hour for 1 square foot area for 1 inch of mercury-pressure difference. The lower the value, the better the vapor retarder. Permeability A rating of a material giving the amount of water vapor that passes through 1 inch thickness of the material.

3 The theory of Condensation Control is really quite simple: You must maintain the surface temperature above dew point temperature. Dew Point (Dew Point Temperature) is the point where saturated air starts to condense. It is a measure of how much water vapor is actually in the air. The warmer the air is, the more water vapor it can hold. The Nature and Cause of Condensation Water vapor is naturally attracted from warmer ambient air to cold surfaces. The water vapor in the air changes to liquid (condensates) at the cooler surface. This same physics applies to cold water piping. If the temperature surrounding the piping drops below the dew point, condensation will form on the pipes. The presence of moisture not only robs the system of its thermal efficiency, it provides suitable conditions for mold and mildew. Relative Humidity A measure of the amount of water in the air compared with the maximum amount of water the air can hold at the current temperature. As the amount of water vapor increases at a given temperature, Relative Humidity increases. An increase in temperature increases the Dew Point and Relative Humidity. Without adequate insulation or the right insulation, the system will achieve equilibrium on the pipe surface resulting in condensation on the pipe. The Value of Closed Cell Protection The optimum, preferred insulation to prevent moisture intrusion has a closed cell structure. The most-frequently selected other option has been open cell insulation, which requires a separate vapor retarder that can fail the moment it s punctured or torn. Open cell material has a non-connecting, random cellular structure. The cells have no walls, so they are porous and cannot block moisture migration or wicking inside the insulation. Care must be taken during and after installation to avoid damaging the vapor retarder. Unlike open cell insulations, closed-cell elastomeric foams like the original AP Armaflex have the vapor retarder built-in. Closed cell insulation has a discrete, noninterconnected cellular structure. It is not porous, because cells have sealed walls which inhibit moisture migration or wicking inside the insulation. The multi-layered structure can t be compromised by surface punctures or tears. AP Armaflex elastomeric foam is a closed cell material, engineered and ideal for chilled water systems when properly installed without a separate, fragile vapor retarder.

4 Moisture Control is Critical to Thermal Efficiency If moisture intrudes the insulating material surrounding cold water piping, thermal efficiency is lost. And for every 1% moisture gain, there is a 7.5% loss in thermal efficiency. In other words, a single percent increase in moisture equates to a 7.5% increase in thermal conductivity (thermal k) or the transference of heat from one surface to another. With chilled water systems, this condition leads to energy loss and higher operating costs. Figure 1 shows the effect of water vapor intrusion on Thermal k. Mark Hayes, our Application Specialist, showing the proper installation techniques for insulation. To better understand thermal conductivity, consider the comparative thermal conductivities of the following: Air Insulation Water Ice 0.15 to 0.18 BTU in/hour sq ft F 0.25 to 0.30 BTU-in/hr sq ft F 4.1 BTU- in/hr sq ft F 15.5 BTU in/hr sq ft F The impact of moisture on thermal performance is obvious when comparing the thermal conductivity of water to insulation. The thermal conductivity of water is approximately 13 times greater than insulation. Therefore, heat transfer from the air to the chilled water pipes greatly increases when insulation gets wet. The heat gain of the chilled water pipes equates to loss of costly cooling BTUs. The cooling system will work harder to compensate for the loss in efficiency and possibly reduce the service life of the system. Effect of Water Vapor Intrusion on Thermal K Figure 1: Every 1% by volume increase in moisture (density) of the insulation yields a 7.5% increase in thermal conductivity. Thermal conductivity of Water equals 4, the point of total saturation of the Insulation material. When the vapor jacket of open cell insulation is damaged, the insulation can relatively quickly reach saturation due to wicking... and result in very high thermal k values.

5 Moisture Control is also Critical to IAQ and Problem-free Facility Operations Moisture intrusion due to compromised insulation systems also creates conditions favorable to mold and mildew. Although mold is a common allergen, the problem of mold infestation cannot be ignored. Mold can grow unseen behind walls and in plenums. The spores easily spread, more so if present in air handling systems. Infestation has caused school and building closings throughout the U.S. and costly litigation for many in the construction industry. Mold requires three key conditions: Moisture, a food source and the right temperatures. Condensation can provide sufficient moisture for mold spores to germinate. Wet pipes or wet insulation can contribute enough moisture for mold growth in existing buildings. Mold needs little more than dust and dirt as food sources or the cellulose kraft paper in vapor jackets on some insulation materials. The final primary requirement, 40 F to 100 F temperature, is nearly always present inside buildings, so the other two factors must be controlled. The removal of fiber insulation is necessary once mold has been found. Practice of Condensation Control Maintain the surface temperature above the dew point. Select closed cell insulation: Armaflex is the closed cell elastomeric insulation invented to prevent condensation, moisture intrusion and loss of thermal k. Use the Armacell ArmWin program to calculate the insulation thickness needed to maintain the surface temperature above the dew point temperature.

6 AP ARMAFLEX: The Original Closed Cell Solution Prevents Moisture Intrusion Excellent resistance to Water Vapor Transmission: Low 0.08 WVT Provides long-term Thermal Performance Non-wicking: Moisture will not migrate through properly installed Armaflex Provides long-term Durability: No fragile vapor jacket The vapor retarder is built-in Multi-layered closed wall cells can t be compromised by surface punctures or rips Withstands abuse during installation Keeps working: Stands up to ongoing maintenance work after building occupancy Helps prevent callbacks, product replacement and costly closings Inhibits growth of Mold and Mildew Minimizes moisture intrusion, the first requirement for mold growth Minimizes the second requirement: No cellulosic vapor jacket, and the smooth surface doesn t trap dust and is easy to clean Provides many other IAQ Benefits: Fiber-free: Won t add fibers to the air stream Clean: Dust-free, dirt-free, non-particulating spaces can remain occupied during reno work Formaldehyde-free: Always has been! Low VOCs: Plus, no off-gassing, which means faster building occupancy Environmentally friendly manufacturing: No CFCs or HCFCs

7 AP Armaflex Assurance System Your peace-of-mind assurance that AP Armaflex is made to the strictest quality, technical performance and environmentally friendly standards. ISO Registration: Ensures that all Armacell manufacturing facilities consistently meet customer requirements... by managing all processes with ongoing quality assessments. Factory Mutual Approval Guide: Ensures consistent performance to published values by monitoring: Fire Performance FM pipe chase test, Flammability test, United Building Code (UBC) 26-3 Room Test WVT ASTM E 96 Thermal Conductivity ASTM C 518 Formaldehyde-Free: Ensures that AP Armaflex is a low-emitting product. It is also low VOC. Closed Cell AP Armaflex for Cold Systems: Adding value, creating better outcomes for Engineers, Owners and Building Occupants!

8 ARMACELL LLC 7600 Oakwood Street Extension P.O. Box 1038 Mebane, NC TEL: FAX: info.us@armacell.com INTERNET: CSB NA NA 2005 Armacell LLC Printed in United States of America