WHAT IS HEATBLOC?
HeatBLOC is a sprayed on metallic, water-based coating with Low-E (Low emissivity) properties. Once properly applied to certain materials such as oriented strand board (OSB), plywood, or other roof decking materials, HeatBLOC reduces the material’s emissivity on the surface to approximately .25 or less. This essentially stops over seventy-five percent of the radiant heat attempting to infiltrate the home. This product has been classified by ASTM as an IRCC or (Interior Radiation Control Coating).
HOW DOES HEATBLOC RADIANT BARRIER WORK?
Because certain building materials like brick, wood, and sheet rock have higher surface emissivity ratings around .7 to .95, they tend to pass this radiant heat to the cooler surfaces penetrating the roof deck and attic spaces. HeatBLOC radiant barrier systems work by lowering this emissivity (to below .23) on the surface, therefore transferring less heat through other materials. Testing has shown that HeatBloc Ultra provides some of the best e-factors reported, outperforming every spray on radiant barrier competitor at .19. In addition, it reflects up to 81 percent of the radiant heat attempting to infiltrate buildings and homes.
WHAT IS A RADIANT BARRIER?
There are 3 ways for heat to penetrate a building enclosure: radiation, conduction and convection. Radiant barriers address the radiant heat transferred by electromagnetic waves, a process known as thermal radiation. Thermal radiation is an invisible form of light that moves through air spaces from a hotter surface to a cooler surface. Hotter surfaces like your roof decking radiate heat into the attic space which is cooler and eventually into the building. A radiant heat barrier reflects this heat back to the outside of the house keeping the inside much cooler.
WHAT IS EMISSIVITY?
Emissivity in a nutshell, is a surface’s ability to transfer or emit heat energy that comes in the form of electromagnetic radiation (long wave). This is measured by giving it a value of 0-1. The less effective a surface is at stopping heat from being transferred the higher this number will be. For example, most wood surfaces have an emissivity rating of around .90 Therefore, when wood get hotter than the other surfaces around it, it has the tendency to transfer approximately 90% of that heat energy via radiation. By applying HeatBLOC to non-porous surfaces, it decreases the emissivity of the surface to around .25 sometimes less. This in turn reflects about 25 percent of the heat energy.
WHAT IS THE LIFESPAN OF HEATBLOC?
WILL IT DEGRADE OVER TIME? One of the many benefits of HeatBLOC is that it has no loss of effectiveness as it ages like many other materials. Foil faced materials can tear and foil chip products tend to collect dust reducing the effectiveness of the product. With HeatBLOC, as long as the surface it is applied to remains in good shape and is free of obstructions, it will only need to be applied one time!
DO ATTIC BARRIERS PREVENT HEAT LOSS?
Radiant barriers are mainly designed to reflect heat out. However, there have been studies done at the University of Kansas that reported up to a 15 percent reduction in the heat that is lost through the attic space when radiant heat barriers were in use.
WHAT IS THE RECOMMENDED COVERAGE RATE FOR HEATBLOC ULTRA? Depending on how porous the surface of the substrate is, around 325 to 50 sq. ft. of coverage is recommended for the application of HeatBLOC Ultra.
CAN HEATBLOC BE APPLIED TO WALLS?
Yes. Since most of the heat gain or loss it through the roof, it is more effective in those areas. However, it can be applied to wall surfaces as long as there is at least 3/4′ air space between the HeatBLOC material and any other material (ie. insulation)
CAN HEATBLOC BE USED IN “VENT-SKIN” TYPE CONSTRUCTION?
Yes. With this type of roof construction, HeatBloc Ultra can be applied to the bottom side of the outermost skin facing downwards into the vent channel. Sidewall applications it should be installed on the inside, again facing the vent channel.
CAN HEATBLOC BE USED WITH RADIANT HEATING SYSTEMS?
Yes. When installed behind wood stoves or on wall surfaces that are next to ceiling mounted radiant heating systems, it reflects heat very well.
IS IT IMPORTANT TO HAVE GOOD ATTIC VENTILATION?
Yes. Radiant barrier systems work independently by controlling the radiant heat load. However, a well ventilated attic will help in controlling the convective heat. Making use of good ventilation with a radiant heat barrier will only improve heating and cooling costs.
DO RADIANT BARRIERS HAVE AN “R” VALUE?
No. An R-value is only given to insulating systems and solid type insulation materials that help stop the other forms of heat transfer. However, testing has shown that HeatBLOC can help increase the effectiveness of insulation anywhere from 87% – 98% respectively.