Performance testing and modeling of a transpired ventilation preheat solar wall : performance evaluation of facilities at Fort Drum, NY, and Kansas Air National Guard, Topeka, KS

This work performed measurement and verification of installed, operational solar wall systems at Fort Drum, NY, and Forbes Field, Air National Guard, Topeka, KS. Actual annual savings were compared estimated savings generated by a solar wall modeling tool (RETScreen). A comparison with the RETScreen modeling tool shows that the measured actively heated air provided by the solar wall provides 57% more heat than the RETScreen tool predicted, after accounting for boiler efficiency. The solar wall at Fort Drum yields a net savings of $851/yr, for a simple payback of 146 years and a SIR of 0.16. RETScreen models indicate that the solar wall system at Forbes Field, Kansas Air National Guard, Topeka, KS saves $9,350/yr, for a simple payback of 58.8 years and a SIR of 0.34. Although results showed that, due to low natural gas prices, the Fort Drum system was not economically viable, it was recommended that the system still be used to meet renewable energy and fossil fuel reduction goals. The current system becomes economical (SIR 1.00) at a natural gas rate of $16.00/MMBTU or $1.60 /therm.