Applications:
Interior Radiation Control Coating (IRCCS)
CLICK HERE FOR INSTALLATION PICTURES
Because of their low emissivity and high
reflectivity, the LO/MIT insulating
paint products are excellent replacements for foil or metalized plastic film radiant
barriers. LO/MIT-I is normally used for new construction since it is
solvent based and not suitable for use in finished structures that are fully enclosed and
not well ventilated. In many cases, LO/MIT-II is the only economical way
to retrofit a radiant barrier since it may be safely applied in enclosed areas at a low
cost. LO/MIT products are classified by ASTM as Interior Radiation
Control Coating Systems (IRCCS) and offer the following unique features:
OVER FIFTY MILLION SQUARE FEET
Low applied cost
INSTALLED SINCE 1986
INSTALLATION GUIDELINES
The LO/MIT insulating paint products may be easily applied using airless or air atomization spray equipment or rollers. LO/MIT-I (IRCCS) is suggested for new construction since the building is normally wide open and ventilation levels are high. LO/MIT-II (IRCCS) is normally used for retrofit or enclosed structures where ventilation levels are lower. Either product requires adequate ventilation and it is suggested that operators wear goggles, respirators or solvent type masks, gloves and disposable or easily cleaned full body covering during application. Ambient temperature should be above freezing for application.
When applying to the underside of roofs, focus the spray swath on the flat undersurface of the decking, allowing the overspray to coat the roof trusses and supporting structures. Roof sheathing may also be pre-coated while still on the ground and stored (painted sides together) for future use. This is a very economical way to apply LO/MIT-I since the sheathing can be placed side by side and very little coating is lost to over-spray. When retrofitting LO/MIT-II to existing buildings, spray application is suggested since the presence of roofing nails may preclude roller application.
Coverage for interior application is normally 400 ft²/gallon when sprayed. LO/MIT-I (IRCCS) will skin dry within one minute after application. Drying to touch will generally occur within 15 minutes to 1 hour depending on ambient temperature and humidity. LO/MIT-II (IRCCS) will skin dry within 10 to 15 minutes after application. Full cure may take from several weeks to six months or more depending on ambient temperature and humidity conditions present. Abrasion is usually not a problem on the underside of the roof, but the slow cure should be kept in mind when building sidewalls are painted.
Air atomization spray equipment should be kept at fairly low pressure (25-35 PSI) to lessen over-spray. Airless equipment should be operated at low pressure and a #613 self cleaning tip has yielded excellent coverage rates.
LO/MIT (IRCCS) should be well mixed before use, and stirred or mixed as often as is practical during use to lessen pigment settling.
LO/MIT must face a minimum 2" airspace, and it must be the last surface facing the airspace. Insulation directly adjacent to the LO/MIT surface should be backed off using 2" air baffles and the LO/MIT surface may not be painted over.
The following ASTM specification gives additional guidelines.
Click HERE for ASTM specifications.
WHAT IS LO/MIT?
LO/MIT is a silver colored, non-thickness dependant, low emissivity coating. When applied to non-porous building materials such as plywood, OSB or plasterboard, LO/MIT lowers their surface emissivity to 0.24 or lower. It is classified by ASTM as an Interior Radiation Control Coating System (IRCCS) and may be effectively used as a radiant barrier substitute.HOW DOES LO/MIT WORK?
LO/MIT Interior Radiation Control Coating insulation works by changing the emissivity of the surface where it is applied. Most building products such as wood, brick, and plasterboard have high emissivities (0.7-0.95). When heated, they radiate most of their heat to cooler surfaces. LO/MIT lowers their surface emissivity to 0.24 or lower, lessening their ability to radiate heat.
WHAT IS A RADIANT BARRIER (IRCCS)?
Heat flows in buildings occur in three ways: conduction, convection and radiation. Radiant barriers or Interior Radiation Control Coating Systems address heat flows by radiation. Radiation is the transfer of heat by electromagnetic waves known as thermal radiation. Thermal radiation is a form of invisible light that travels through the air from a warm to a cool surface. Warm surfaces, such as roof decks warmed by the sun, will radiate or emit their heat to cooler interior building surfaces. A radiant barrier is a low emissivity surface placed in the path of thermal radiation that blocks heat transfer. An IRCCS is a spray-applied substitute for a radiant barrier.WHAT IS EMISSIVITY?
Emissivity is the ability of a surface to radiate or emit energy in the form of long wave electromagnetic radiation. It is represented by a value from 0 to 1. The closer the value is to 1, the less effective the surface is at impeding radiant heat transfer. Wood has an emissivity of 0.72. Thus, when wood is heated above the temperature of surrounding surfaces, it will tend to transfer 72% of its heat energy by radiation. LO/MIT, when applied to most non-porous surfaces, will decrease the surface emissivity to 0.24 or lower, allowing only 24% of the heat energy to be transferred by radiation.WHERE IS THE AIRSPACE WHEN USING LO/MIT?
To function effectively, the low emissivity surface of a radiant barrier (IRCCS) must face an airspace of 2" or greater. A radiant barrier (IRCCS) will not function if sandwiched between two solid surfaces. LO/MIT, when installed on the underside of roof decking, normally faces downward into the attic, an airspace substantially larger than 2". If insulation is installed in the cavity formed by the roof trusses and roof decking (as in a cathedral ceiling), at least 2" should be allowed between the top of the insulation and the LO/MIT surface.
DOES LO/MIT ADVERSELY EFFECT ROOF SHINGLES?
Absolutely not! LO/MIT has never caused shingle damage in any installation. Extensive testing at the Florida Solar Energy Center has shown that the use of radiant barrier (IRCCS) results in, at most, a 2-3 degree rise in shingle temperature. Please read this article for more information about the effect on shingles with use of a Radiant Barrier (IRCCS) on the underside of the roof. DOES LO/MIT DEGRADE OVER TIME?Unlike some insulation products, LO/MIT does not lose its effectiveness over time. Test samples installed experimentally over 20 years ago still have the same emissivity levels today, as they did when originally installed.
WHAT IS THE COVERAGE RATE FOR LO/MIT?Recommended coverage for LO/MIT on plywood is 400 square feet per gallon; on OSB or particleboard, 450 square feet per gallon when sprayed. Focus the spray swath onto the flat decking surface, but allow overspray onto the trusses for an ideal application.
WHAT IS THE RECOMMENDED APPLICATION METHOD FOR LO/MIT?
Spray application using airless or air atomization equipment. If airless, a #613 self-cleaning tip is recommended. If air, use a nozzle suitable for a low viscosity product and try to keep the gun pressure reasonably low (25-35 PSI) to lessen over-spray. A pump type insecticide sprayer may also be used, however, coverage rates will suffer and the solvents used in LO/MIT-I may ruin the sprayer after one use.
IS LO/MIT PERMEABLE TO WATER?Yes! LO/MIT allows water vapor to permeate, and does not trap water vapor within roof decks or sidewalls. If the roof were to develop a leak, the moisture will pass through LO/MIT, allowing the problem to be easily identified and repaired. LO/MIT will also not delaminate when re-roofing nails are put through the roof decking. These are major advantages for LO/MIT over other radiant barrier products, as the homeowner can avoid potential problems in the attic.
CAN LO/MIT BE USED ON SIDEWALLS? Yes, but LO/MIT is normally more effective when used under roofs. Low emissivity surfaces become more effective in controlling radiant heat transfer as the temperature of the radiant heat source increases. Roof surfaces are generally much hotter than sidewalls. However, in tropical climates where no insulation is used in sidewalls, LO/MIT can substantially help increase interior comfort levels. CAN LO/MIT BE USED IN VENT-SKIN CONSTRUCTION? Yes. In vent-skin roofs LO/MIT should be applied on the underside of the outer roof skin facing down into the vent channel. On vent-skin sidewalls LO/MIT should be applied on the inside of the outer skin facing into the vent channel. CAN LO/MIT BE USED WITH RADIANT HEATING SYSTEMS? Yes. It is an effective heat reflector when used behind wood stoves or on walls adjacent to ceiling mounted radiant heaters in commercial applications.IS ATTIC VENTILATION IMPORTANT?
Very! Radiant barriers (IRCCS) only control radiant heat loads. Good attic ventilation helps control convection loads. Together they raise the comfort levels and lower cooling costs. Venting to allow 2.5 air changes per hour should be specified as a minimum. DO RADIANT BARRIERS (IRCCS) LOWER HEATING COSTS? Yes, but only modestly. They are most effective at lowering cooling costs.DO RADIANT BARRIERS (IRCCS) HAVE AN "R" VALUE?
No. R-values apply only to solid insulation or to insulating systems that control heat flows other than radiation. When LO/MIT is installed in combination with R-19 insulation, the combination yields a total R-value of R-34 for heat influx. In this example, LO/MIT has an "apparent" R-value of R-15 because it improves the efficiency of the current insulation. DO YOU HAVE ADDITIONAL QUESTIONS?
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The Florida House The Florida House Learning Center, located in Sarasota, Florida, demonstrates appropriate design strategies and technology for hot, humid climates. The house is a "traditional" model featuring cost effective and affordable energy conservation methods through "off-the-shelf" technology including solar domestic hot water heating and the application of LO/MIT on the undersurface of the roof.Jennings-Pearman Energy Division,
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The Lifestyle 2000 HouseLocated in the NAHB Research Park in Gaithersburg, Maryland, this house demonstrates energy conservation and reduced maintenance costs through the use of concrete and masonry products. The entire undersurface of the roof is coated with LO/MIT to lower air conditioning costs. |
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The Resource Conservation House Located in the NAHB Research Park in Gaithersburg, Maryland, this house demonstrates energy efficiency, recyclable materials and solar technology with an emphasis on enhanced durability and low maintenance costs. The entire undersurface of the roof is coated with LO/MIT to lower air conditioning costs.
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LO/MIT shown being applied to underside of
flat roof. Note use of extension wand on airless sprayer for ease of application. Thermal Advantage, |
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LO/MIT IRCCS shown being applied to underside of peaked roof in attic area. |
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LO/MIT-I being applied to underside of galvanized roof in chicken house at University of Georgia, Athens, Georgia. LO/MIT-I is an excellent metal building insulation because it lowers interior radiant temperature, in this case, lessening heat loads and death rates during extreme summer heat. |
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Contrast between uncoated and coated (right side) underside of chicken house roof at University of Georgia. LO/MIT-I increases interior lighting levels and lowers radiant temperatures, making an excellent metal building insulation in agricultural applications. |
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LO/MIT installed on underside of 15,000
square foot wood deck tiled roof fire station, Naples, Florida. The combination of LO/MIT
and tiled roofs is an excellent method to increase comfort and lower cooling loads in hot
climates. Jennings-Pearman Energy Division, |
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LO/MIT installed on underside of wood deck metal roofed humane society headquarters, Naples, Florida. LO/MIT was also installed on the underside of the roof areas over the open air animal storage pens in the rear of the building to keep the animals cooler. |
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LO/MIT installed on underside of standard asphalt shingled roof of golf pro shop, Naples, Florida. Notice continuous ridge vent used to improve attic ventilation. |
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LO/MIT installed on underside of wood deck tiled roof house. An excellent combination of light colored, high thermal mass roof with interior radiant barrier to keep attic cavity cooler and increase interior comfort levels. |
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Photovoltaic battery storage and control room showing LO/MIT-I
on all interior surfaces. The use of LO/MIT-I in photovoltaic
installations extends battery life and improves the installation efficiency by lowering
interior temperatures. Batteries and inverters operate more efficiently at lower
temperatures. Energy Conservation Services, |
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LO/MIT-II interior radiation control coating
installed as a metal building insulation on the underside of the steel roof of a hardware
supply building. Note that all supporting beams and purlins were also painted, raising
interior lighting levels. Owner reported that interior temperatures were up to 20°F
cooler after LO/MIT was installed. Cordell
Lumber Co., |
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LO/MIT applied to underside of roof decking
on unique Enertia superinsulated Aquarius 2 log home. Enertia
Building Systems, |
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University of Texas 2002 Solar Decathlon Design Competition House
LO/MIT-II was spray applied to the underside of the metal roof panels, and the inside surface of the Hardy Plank siding, increasing the the roof R values +15 and the side wall R values +7 (for heat influx). Integrity Energy Coatings,
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LO/MIT-I applied to large glass windows above entry/exit
doors to prevent heat influx into vestibule. Though LO/MIT blocked
the light transmission, vestibule temperatures dropped by 20+ degrees F. Sands Expo and
Convention Center |
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LO/MIT-I IRCCS spray-applied to steel sidewalls of large
construction storage warehouse. Integrity Energy Coatings, |
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LO/MIT-I IRCCS
Spray-applied to underside of steel roof decking and trusses in an ice
hockey arena. LO/MIT also dramatically increases interior
lighting levels. Jensa Peinture, Montreal, CANADA, Phone: 514-389-6111 |
