The laboratory air handling unit (LAHU) system for laboratory buildings has been developed. and optimized. Theoretical study has concluded that the LAHU with optimal outside air control and optimal heat recovery control significantly reduces thermal energy use, saves pump power consumption and improves office indoor air quality. This paper presents validation experiments of the LAHU energy performance for the winter operation in a large university research building including detailed experimental methodology, procedures and experimental energy savings results. The experiments establish that the LAHU can reduce annual heating energy consumption by over 30% and can reduce heat recovery pump power by over 50% per year for this typical laboratory building. The experimental validation of the LAHU for the summer operation will be reported in a followup paper