Did you know that an AAON HVAC cabinet can help you save money? As utility costs increase, poor insulation and poor air seals will result in more wasted heating and cooling dollars. Architects, engineers, and owners know that utilizing quality materials and construction techniques will minimize losses in the building.
For instance, the ASHRAE standard 90.1- 2010 requires all above deck insulation in climate zones 2 through 8 to have a minimum thermal insulating value of R-20 and climate zone 1 to have a minimum R-13. Likewise, ASHRAE 90.1-2010 requires sealing, caulking, gasketing, or weather-stripping of various areas of the building envelope. Like the building, the Heating Ventilation and Air Conditioning (HVAC) cabinet can lose energy through poor insulation and air seals.
Like the building, the HVAC cabinet should have requirements for minimum insulation and air seals. An HVAC cabinet can become a pathway for heating and cooling energy to enter or escape from a building.
Conventional HVAC cabinets incorporate narrow one-half to one inch fiberglass insulation attached to a single wall of galvanized sheet metal. Thermal resistance values for fiberglass panels are typically less than R-2. The R value of a fiberglass panel is reduced even more without a thermal break between the HVAC tunnel air temperature and the outside ambient air temperature. Due to the lack of published standards on the HVAC cabinet air leakage, air infiltration percentages are not available. Although air infiltration rates may vary between manufacturers, 4’k of total airflow at 1 inch of internal negative static water pressure can be used as a representative leakage rate.
AAON utilise une approche différente. Il fabrique un panneau de mousse de polyuréthane rigide à paroi souple avec rupture de pont thermique pour le conduit d’air du caisson HVAC. En mettant en place une structure composite, la mousse et la tôle sont réunies dans un caisson à isolation et étanchéité à l’air améliorées. Le panneau AAON de deux pouces a une résistance thermique de R-13. Cela équivaut à utiliser des panneaux à rupture de pont thermique et fibre de verre de 4 pouces d’épaisseur, 0,5 livre par pied carré. Cela se trouverait généralement sur des équipements personnalisés plus coûteux. Tous les panneaux AAON intègrent des ruptures thermiques pour séparer la température de l’air du conduit HVAC de la température de l’air ambiant extérieur. Des tests sur caisson ont démontré que le taux d’infiltration d’air est inférieur à 1,5 % du débit d’air total à 1 pouce de pression d’eau statique négative interne.
AAON uses a different approach. AAON manufactures a double wall Rigid Polyurethane Foam panel with thermal breaks for the HVAC cabinet’s air tunnel. By implementing a composite structure, the foam and sheet metal are combined into a cabinet with improved insulation and air seals. The AAON two inches wall panel has a thermal resistance of R-13. This is equivalent to using panels with thermal breaks and four inches thick, 0.5 pounds per square foot fiberglass. This would commonly be found on more costly custom equipment. Ail AAON panels incorporate thermal breaks to separate the HVAC tunnel air temperature with the outside ambient air temperature. Cabinet testing has shown the air infiltration rate is below 1.5% of total airflow at 1 inch of internal negative static water pressure.
The increased insulation of an AAON cabinet will reduce the undesired heating and cooling of the cabinet airstream due to the outside ambient temperature. By improving air tightness, the AAON cabinet reduces any load created from the outside air. One benefit of an AAON cabinet is a reduction in owner’s operating cost u to 22 % each year.
The utilization of the AAON foam panel design has improved:
The conventional fiberglass insulated cabinet creates a thermal bridge for heating and cooling energy between a building’s interior and the outside environment. The AAON Rigid Polyurethane Foam cabinet saves cooling and heating energy through improved insulation and air seals. This reduces the energy lost to the environment and reduces the building owner’s operating cost. Saved energy is saved money.
Rigid Polyurethane Foam Panel Design
The manufacture of AAON Rigid Polyurethane Foam implements cutting edge technology. Low viscosity polyurethane liquid is injected into a galvanized steel casing with integrated thermal breaks. As the liquid foam fills the casing, trapped air escapes through designed openings. After the casing is evacuated of all air, the polyurethane liquid is cured through a pressurized baking process. The resulting closed cell foam core has a density of two pounds per cubic foot. This composite design results in improved operating costs, thermal resistance and breaks, air seals, rigidity, impact resistance, maintainability, indoor air quality, and equipment lifetime.
The one-half to one inches thick fiberglass panels used in conventional HVAC cabinets will have a thermal resistance of R-0.5 to R-3.5. AAON Rigid Foam Panels utilize two inches thick walls and a two and one half inches thick roof. The foam panels have a thermal resistance of R-13 and R-16 respectively. This is equivalent to four inches of fiberglass commonly found in more costly custom HVAC cabinets.
Conventional fiberglass cabinets have sheet metal panels that have no thermal break, creating a direct pathway from the cabinet’s interior to the atmosphere. The published R-value of fiberglass insulated cabinets is much less because of this thermal bridge.