I recently learned how “foam aging” can seriously reduce the thermal efficiency of insulated piping systems. Like a deflating helium balloon, foam insulation can loose as much as 28% of its insulating efficiency within a few years after installation. With district heating and cooling pipe systems expected to have a lifespan of 20+ years, this sharp drop in efficiency can represent increased and long-lasting operating costs for the facility.
If you are involved in the design of energy-efficient facilities, I encourage you to read this Technical Paper, which illustrates the problem, and provides a practical solution with long-term benefits for your client. Oh, and have a Happy Earth Day!