LCC Optimization of Different Insulation Materials and Energy Sources Used in HVAC Duct Applications

Abstract

The heating, ventilation and air conditioning (HVAC) ducts distribute the conditioned air to different zones. They are installed outside in a harsh environment which escalates the energy loss due to heat transfer. This study aims to estimate the economically feasible and environmental amiable insulation thickness for HVAC duct using life cycle cost (LCC) and environmental assessment method. It deems five insulation materials for the duct and eight energy sources for chiller operation in selected countries. It uses the design and operating parameters of the duct installed in a renowned pharmaceutical company at Jamshoro/Pakistan. An apropos mathematical model is developed using the collected parameters to calculate optimum insulation thickness (OIT), LCC, maximum energy savings (ES) at minimum payback period (PP) and emission reduction in the insulated duct. It examines the effect of insulation thickness on economic and environmental outcomes using the linear slope line regression method. The results revealed that the use of EP and natural gas has minimum LCC of 13.66 $/m-year (− 0.484), 95% ES (0.248) corresponding to OIT (64.64 mm) with minimum PP of 1.2 years (decreasing at a rate of − 3.69 with insulation thickness). Fuel consumption reduces dramatically (− 0.79) and once OIT is achieved, further increasing insulation thickness has a negligible impact on fuel savings (− 0.041). Higher fuel cost produces maximum ES in the duct and reduces PP of insulation cost in selected countries but they do not affect the variation in fuel consumption and CO, $$\hbox {CO}_{2}$$ and $$\hbox {SO}_{2}$$ emission. Additionally, OIT of EP for duct reduces CO and $$\hbox {CO}_{2}$$ emission at a maximum rate of -0.134 in case LPG (96%) and − 0.484 (95%) in the case of natural gas, respectively.