There are many good reasons to install reflective insulation in a barn. The main reasons are that reflective insulation will increase the level of comfort for both humans and livestock and regulate temperatures in the building throughout the year in either a cold or a hot climate. It will also reduce your energy bills and thus save you money. Shopping online is the new way to shop for your insulation. It allows you to compare more insulation and to find the best price. Another advantage of shopping on the internet is that the insulation will be delivered directly to your door in just a few days! Once installed, reflective insulation will be effective in controling the heat or cold, and to reduce or eliminate moisture and drafts. As reflective insulation plays a major role in condensation control, it is recommended to install it in all barns including those that are storage only to protect the contents from moisture damage. It is always best to choose a product that is Energy Star qualified and/or ICC-ES recognized because the quality and the performances of the product have been checked. Some of the reflective insulations also provide a soundproofing benefit. Maintaining consistent indoor temperatures using a combination of reflective insulation and ventilation will protect your investment in equipment, livestock and crops. Insulate all dairy barns, poultry houses, stables, hog barns, pole barns, silos, metal barns, outbuildings, storerooms, storage sheds, and steel or metal buildings.

One of the main purposes of installing insulation in a barn is to prevent heat stress on livestock. Heat stress prevention is a major issue for dairy barns, poultry houses and any barn where animals live indoors during the summer months or in warmer climates.

Reflective Insulation Provides an Aesthetic Finish for a Barn

Heat stress is a function of air temperature, humidity, air flow and solar radiation. Protection from solar radiation is paramount in barns where the temperature is 60 F or above. Absorption of solar radiation causes heat stress in livestock beyond that of the actual air temperature. Since cattle sweat at only 10% of the human rate, they are particularly susceptible to heat stress. Reflective insulation installed as a radiant barrier will reflect 97% of solar radiation thereby protecting livestock from stress.

The negative effects of heat stress are well documented in dairy barns and poultry houses. Dairy cow can spend over 90% of the day inside a freestall barn. Heat stress can cause significant milk production and reproduction losses. Negative impact on milk production is noticeable at temperatures above 80 F. Once indoor temperatures climb above 90 F, milk production decreases can range from 3% to as much as 20%.

Dairy Cows in a Freestall Barn

Poultry also need to maintain constant a body temperature. Birds under heat stress have a difficult time keeping themselves cool as they do not sweat and must rely on panting to lower their body temperature. Excessive panting can result in the production of thin-shelled eggs, decreased egg production, smaller egg size, reduced growth rate and reduced hatchability rate. Heat stress in roosters causes decreased sperm quality, viability and fertility. Acute heat stress can result in death.

Heat stress on livestock inside a barn is primarily due to the black globe effect - a condition that manifests when livestock absorb large amounts of solar radiation transferred from the hot roof and building walls. High humidity compounds this problem. Solar energy absorption can be prevented by installing reflective insulation under the roof and in the barn walls. Reflective insulation is the only type of insulation that blocks radiant heat. Insulating with reflective insulation will control indoor temperature, reflect heat away from the building, control condensation inside and prevent heat stress/black globe effect.

Broiler house

The four environmental factors that determine thermal comfort are airflow, air temperature, humidity, and radiation from the sun. Temperature is measured inside a barn using the Wet Bulb Globe Temperate (WBGT) heat stress index that combines ambient air temperature, humidity and level of radiant energy. This is considered a more realistic way to measure heat stress on livestock than ambient air temperature alone. A WBGT kit would consist of a Dry Bulb (DB) that reads actual air temperature when shielded from sunlight, a Wet Bulb (WB) that uses a moistened wick over the bulb to calculate temperature and humidity level based on the rate of evaporation, and a Black Globe to measure the intensity of solar radiation.

A Black Globe Temperature (GT) thermometer is a black copper ball with dry bulb inside that measures the intensity of radiant energy to give a temperature that reflects not just how warm it is but how warm it feels. The effect of radiation is important under all temperature conditions as excess radiation always increases the heat load on an animal.

The formula for calculating the heat stress index is:
WBGT Index = 0.7 WB + 0.2 BG + 0.1 DB

Reflective insulation is the builder's choice for barns and steel buildings as it provides thermal insulation, a radiant barrier and a vapor barrier to eliminate condensation problems in one product. The reflective surface also provides an attractive finish and enhances the lighting efficiency inside the building. It is commonly used for walls, under the roof decking, under the floor, and around ducts and pipes.

Reflective insulation is made of two layers of foil with a core layer of foam or plastic bubbles in between creating an air space. Reflective insulation products incorporate trapped air spaces as part of the system to retard the convective flow of heated air the same way fiberglass insulation does. Reflective insulation with a foam core will provide thermal heat resistance up to R-14.5 - the highest R-value per inch of any available type of insulation. It can be installed alone or in conjunction with other types of insulation like rigid foam board for colder climates. Barn roofs should be insulated to R-25 and walls should be insulated to R-14 depending on climate conditions.

Radiation accounts for 65-85 percent of all heat transfer through the walls and roof. Reflective insulation is an effective barrier against radiant heat transfer because it reflects back almost all of the infrared radiation striking its surface and emits very little of the heat conducted through it. The aluminum foil component in reflective insulation will reduce radiant heat transfer by as much as 97 percent. This keeps the building from getting hot inside in summer and keeps warm air inside in winter.

• Reflective insulation has higher R-values (or resistance to heat transfer) than any other type of insulation per inch. ¼" thick reflective insulation has more insulation value than 6 inches of common fiberglass batt.
• Reflective insulation is the only type of insulation that reflects radiant heat. Traditional fiberglass insulation has no effect on radiant heat transfer. Estimates are that between 80% and 90% of the radiant heat striking fiberglass will pass right through it. Aluminum foil reflective insulation, which can reflect up to 97% of the radiant energy that strikes it, has proven to be an outstanding radiant heat barrier.
• Reflective insulation is the only type of insulation that can be used as a vapor barrier. All other insulation requires the addition of a separate vapor retarder to prevent moisture accumulation in the walls and ceilings that can cause rot, mold, fungus, and dripping.
• Reflective insulation will not compress or absorb moisture - conditions that seriously degrade the performance of batt and blanket insulation.

The benefits of using reflective insulation instead of conventional bulk insulation are numerous.

• Up to R-14.5 thermal resistance
• Clean, lightweight, flexible and very strong
• Very thin - can be used effectively in small spaces
• Easy to install
• Installation requires no special tools or clothing
• Easier to cut than fiberglass batt and bubble wraps
• Can be stapled, nailed, glued or sewn
• Non-hazardous/Non-toxic/Non-carcinogenic
• Safe for workers to use as there are no fibers to breath or cause skin irritation
• Provides up to 19 DB of soundproofing
• Works in temperatures extremes as low as (minus) -20 degrees Celsius and as high as 80 degrees Celsius (and if an air space is added it can go up to 300 degrees Celsius)
• Vapor Barrier, waterproof, non-absorbent - reduces or eliminates condensation when properly installed
• Radiant barrier - reflects 97% of radiant heat
• Does not promote mold, mildew or fungus growth
• Does not provide nesting for birds, rodents or insects
• Is used in animal confinement buildings to reduce the "black globe effect"
• Provides Class A/Class 1 fire rated protection - meets fire and smoke safety requirements of most federal, state, and local building codes
• UV resistant
• Flexible at low temperatures
• Withstands fluctuations in outdoor temperatures
• Reinforced (Commercial Grade)
• Saves money and energy

Click here for comprehensive information the different types of reflective insulation.

Metal buildings are very good conductors of heat. Radiant heat from the sun that strikes the metal roof will be carried inside very efficiently unless a radiant barrier is in place. Installing a radiant barrier will reflect the sun's infra-red rays back into the atmosphere so they will not penetrate the building. This will keep the interior much cooler and save money on lower air conditioning bills or eliminate the need for air conditioning entirely.

Radiant barriers are made of aluminum foil sheeting with a backing for stability so it can be installed without tearing. They have become increasingly popular because tests by the Florida Solar Energy Center (FSEC) and Oak Ridge National Laboratories throughout the 1980s and 1990s show that they work, and also because manufacturers have improved the quality of radiant barrier materials making them easy and affordable to install.

Radiation is the transfer of heat (infra-red radiant energy) from a hot surface to a cold surface through air or a vacuum. Radiation is the dominant method of heat transfer in a building accounting for 65-85 percent of all heat transfer through walls, roof, and floors. Aluminum foil is an effective barrier against radiant heat transfer because it reflects back almost all of the infrared radiation striking its surface and emits very little of the heat conducted through it.

Traditional fiberglass insulation has no effect on radiant heat transfer. Estimates are between 80 and 90% of the radiant heat striking fiberglass will pass right through it. Aluminum foil reflective insulation, which can reflect up to 97 percent of the radiant energy that strikes it, has proven to be an outstanding radiant heat barrier. All new steel buildings that will hold people or animals should incorporate a radiant barrier including buildings in mild climates where you do not need to air-condition the building for part of the year.

Reflective Insulation Installed as a Radiant Barrier in a Steel Building

Condensation is a special problem with fiberglass insulation in steel buildings

Inside a building, water vapor will condense whenever it comes into contact with a surface that is cold enough. The air will lose heat to the cold surface through conduction. As the air cools, the dewpoint drops and relative humidity increases until the cooler air is saturated, at which point condensation occurs.

Adding traditional fiberglass batt insulation to slow the loss of inside heat from a steel building creates a problem. Instead of warm air rising and striking the metal walls and roof directly causing condensation and dripping, the insulation will make the air cool more gradually. The warm, moist indoor air will cool and reach the dewpoint either somewhere inside the insulation or when it reaches the roof or siding trapping moisture. Moisture trapped within the insulation will cause its R-value and effectiveness to drop dramatically as water is a very good conductor of heat. Even though the metal in a quality steel building will be treated, water trapped between the insulation and the building exterior will, over time, cause rust, oxidation, mold and fungus growth - conditions that will degrade the steel walls and shorten the service life of the building. Condensation can also result in ruined crops or bacterial growth.

A vapor retarder installed on the warm side of the insulation will act as a physical shield to repel moisture, keeping it inside in the form of water vapor. A vapor retarder like aluminum foil or polyethylene sheeting will slow the movement of water vapor. Some small amount will still get through and proper ventilation at the roof is necessary for this to escape. Air infiltration through the building exterior in humid areas will also allow some moisture in below the roof decking and into the insulation. As any amount of moisture seriously degrades the insulation capabilities of fiberglass batt insulation, fiberglass is not recommended for use in steel buildings in humid areas. Reflective foil insulation is recommended instead as it both insulates and creates a vapor barrier that protects the building exterior.

Sources of Moisture

Human beings and animals give off a significant amount of water through breathing and perspiring. Any other processes in the building that use water, such as steam cleaning or food processing, will add to the moisture content of the air. Gas, oil and propane space heaters give off considerable moisture through the process of combustion as well.

Condensation in an un-insulated steel storage building can damage the contents inside through dripping. The primary cause of condensation in un-insulated steel storage sheds is moisture wicking up from the ground and evaporating inside the building. The building needs to go onto a base which includes a vapor retarder like aluminum foil sheeting to stop this rising dampness.

Excavated earth will also give off a significant quantity of moisture as the soil is exposed to air. If the building is closed over a dirt or gravel floor, this moisture will stay inside the building. Freshly poured concrete is another significant source of large amounts of moisture. If concrete is poured after the building is closed, the building will have to be ventilated to remove all this extra moisture.

In steel buildings, visible condensation occurs on exposed surfaces while concealed condensation occurs within the insulation or roof and wall cavities.

Visible condensation

Visible condensation shows up when moisture appears on the inside surface. This is the nuisance type of condensation you see on windowpanes and purlins that results in dripping. Visible condensation can be controlled with ventilation and the addition of reflective insulation. The insulation will reduce the cold surface area where condensation is likely to occur. Running the insulation over the inside of steel framing members will reduce this even further.

Ventilation to exchange indoor air with high moisture content for outdoor air of lower moisture content will even further reduce visible condensation. Keeping fans running to circulate the air will decrease the excess humidity in the air as well. Installing a vapor barrier under the floor during construction will also help prevent the problem.

Concealed condensation

Concealed condensation is a more difficult problem and can cause more damage than visible condensation. Concealed condensation occurs when vapor has passed through the insulation or the vapor barrier to condense either inside the insulation or on the metal surface of the roof or exterior wall. It is best controlled during construction by having proper ventilation in the roof and a tight vapor barrier on the warm side of the wall.

Fiberglass batts will hold moisture inside as either water vapor or condensed moisture both of which negate its effectiveness as an insulating material. Removing moisture from fiberglass insulation once it gets inside is difficult and replacement is usually called for.

Preventing concealed condensation is the most effective means of control. Proper use of a vapor barrier is critical. As vapor barrier will significantly reduce the movement of vapor transmission but not stop it completely, it is more appropriately called a vapor retarder. The ability of a material to resist water vapor is called permeance. A material must have a permeance of less than 1 grain of vapor transmitted per hour per square foot per inch of mercury vapor pressure difference in order to be considered suitable for use as a vapor retarder.

Aluminum foil reflective insulation has a perm rating of 0.05 making it an excellent vapor barrier. When properly installed, waterproof reflective insulation can reduce or eliminate condensation. As reflective insulation is non-absorbent, it will not mildew or promote fungus growth. It can be stapled, nailed, or glued in place. As the Foil-Foam-Foil and Foil-Bubble-Foil types of reflective insulation products carry R-values of up to 14.5, they can double as wall/roofing insulation and vapor barrier in one.

Properly insulated concrete or masonry wall barns will prevent heat loss and control moisture.
Even in a properly ventilated barn, condensation often forms on block or masonry walls during very cold weather. Insulation is the only way to prevent condensation on the interior walls.

Reflective insulation installed on the barn interior will provide a very efficient air barrier, preventing drafts along with condensation control. In colder climates, a layer of rigid foam or spray foam insulation can be installed against the wall first for added thermal resistance.

Concrete blocks Rigid insulation 1" Metal strapping (air space) Reflective Insulation Metal strapping (air space) Drywall

1. Attach the rigid insulation to the blocks
2. Screw the first metal strapping to the wall through the rigid insulation
3. Stick Reflective Insulation to the metal strapping with double faced tape. Just stick it temporarily prior to the installation of the wood strapping
4. Seal all seams with aluminum tape
5. Install the second strapping and drywall following the manufacturer's recommendations

Pole Barns

1. Install between framing and sheeting
2. Place double-sided tape on frame
3. Roll out insulation over frame
4. Allow insulation to sag slightly (approx 1 inch)
5. Attach your sheeting as if the insulation wasn't there
6. Tape seams with metal tape

Reflective insulation installed in a pole barn

Click here for instructions for both new and retrofit installations using reflective insulation in a pole barn.

Chastain, John P.,
"Improving Mechanical Ventilation in Dairy Barns, AEU-3",
University of Minnesota Extension Program, 2008.

"Wet Bulb Globe Temperature",
Wikipedia.org.

Keown, Jeffrey F.; Kononoff, Paul J.; Grant, Richard J.,
"How to Reduce Heat Stress in Dairy Cattle",
University of Nebraska, October 2005.

"Avoiding Heat Stress Problems for Poultry",
Illini Poultry Net, University of Illinois Extension, 06/13/2001.

"Heat Stress in Poultry:Solving the Problem",
Department for Environmental Food and Rural Affairs, www.defra.gov.uk, 2005.