Efficient Radiant Heat System Utilizing EPS Rigid Insulation
Established in 1942 and named after legendary Army scout Kit Carson, who explored much of what is now the western United States, Fort Carson is a U.S. Army installation located in Colorado Springs, Colorado. Known as the Mountain Post, at 137,000 acres Fort Carson is one of the U.S. Army’s most important multi-functional bases and has been home to nine different divisions throughout its history. A key component of the Mountain Post’s multi-pronged utility is Butts Army Airfield, which was built to accommodate light, fixed-wing aircraft. Originally constructed in the 1950s, by 2016 the 60-year-old outdated airfield was deteriorating, and the Army wanted a new, larger airfield and modern, state-of-the-art facilities to service, store, and support aircraft stationed at Fort Carson.
Under the rigid guidance of the U.S. Army Corps of Engineers (USACE), the Butts Airfield rehabilitation project included paving 14 acres of concrete covering a longer runway, airfield aprons, and new supportive aircraft hangars. A key component of the improvement was the installation of a new Attack Hangar designed to house AH-64 Apache helicopters. The large, open-span pre-cast concrete building was intended for year-round use as an aircraft maintenance facility where military personnel need to be comfortable working even during winter months with the massive hangar doors wide open.
Atlas Molded Products integrates into the project at the intersection of human thermal comfort and functional necessity, by providing the layer of molded polystyrene insulation installed between the hangar’s concrete floor and the ground below. Molded polystyrene insulation materials are made from closed-cell polystyrene, which is often chosen over similar but distinctly different extruded polystyrene (XPS) rigid foam insulations. Atlas Molded Products’ line of architectural insulations provides owners and builders with stable R-values between 4.2 and 4.5 per inch and high-compressive strengths ranging from 15 to 60 psi. Molded polystyrene insulation dries quickly dry after wetting conditions, which greatly facilitates rigid foam insulation’s ability to maintain established R-values for the life of the building. This translates to more efficient long-term operations where heating and cooling are concerned.
The Challenge
The new Attack Hangar at Fort Carson is a massive, open-span building of 142,000-SF that is designed to accommodate up to six AH-64 Apache attack helicopters. Along with modern maintenance shops that did not exist in the previous hangar, the building includes secured pre-flight planning rooms, flight operations, and support facilities for the helicopters and their crews. The state-of-the-art AH-64 Apaches are equipped with advanced weaponry, targeting, avionics, and highly redundant systems and anti-armor; all of which combine to make essential maintenance anything but routine. Keeping these $20 million aircraft ready to fly at a moment’s notice is a never-ending task for the 4th Combat Aviation Brigade stationed at Fort Carson.
Efficiently maintaining thermal comfort in an open-span building of this size regardless of external weather conditions was important to the USACE. Radiant heating built into the hangar’s concrete floor was an essential part of the solution.
The Solution
As much as 50 percent of a building’s heat loss occurs through the slab and perimeter of the foundation, making the below-grade thermal barrier vital to efficiently achieving thermal comfort in the large, high-ceiling facility. In the Attack Hangar, the floor is made of 4,200 yards of concrete, meaning a very large surface area from which heat can escape. In-floor radiant heating incorporates a heating system installed beneath a concrete floor before the slab is poured. The radiant heating system incorporates specialized plastic tubing that allows a hot liquid to be circulated beneath the floor.
For the USACE and the Army, a key facet of maximizing the return on investment in the radiant heating focused on controlling the heat’s direction of dissipation. The USACE’s design specification called for a layer of rigid foam insulation beneath the tubes and Atlas Molded Products’ molded polystyrene insulation was chosen for a combination of thermal resistance and compressive strength. The heat within the tubes radiates up through the concrete and is released into the surrounding air via convection.
Molded polystyrene insultations are well known for their ability to support stable, lifelong R-values whereas the R-value of competing XPS insulation diminishes over time as the material off-gasses blowing agents used in the manufacturing process. Molded polystyrene’s ability to quickly dry after natural wetting conditions also adds to R-value retention, whereas XPS materials have been shown to retain more water in real-world conditions, which further decreases long-term thermal effectiveness.
Meant to hold the weight of six fully loaded Apache attack helicopters and all of the supportive equipment and manpower as a live load, molded polystyrene’s compressive strength was also a significant consideration. Atlas manufacturers below-grade insulations that span a range of compressive strengths stretching from 15 pounds per square inch (psi) up to 60 psi. In the case of the Fort Carson attack hangar, the highest strength material (60 psi) was chosen to assure that the hangar floor can easily withstand the pressure of the most intense use it will ever face without fear of failure.
Finally, as builders of American military and civil engineering projects ranging from buildings to dams, canals, and flood protection infrastructure, the USACE has a keen interest in incorporating high-quality, American-made products wherever possible. Atlas Molded Products manufactures rigid foam insulations, geofoam products, and many other forms of block and shape molded polystyrene from 14 U.S. manufacturing facilities and is proud to be American owned and American operated.
Molded polystyrene rigid foam insulation from Atlas Molded Products has earned its stripes on the new Attack Hangar at Fort Carson. As an under-slab insulation, molded polystyrene’s proven performance has met and exceeded the USACE’s rigorous expectations for performance, stability, durability, and long-term cost-effectiveness. American made and proud of it, molded polystyrene insultations from Atlas Molded Products combine significant strength and non-diminishing R-value with ease of installation and readily, locally produced materials to meet the needs of the U.S. Army, the USACE, and countless other North American customers wherever they are and whatever they may be.
