This paper present a survey technique for rating HVAC systems. System components are grouped into categories. The components inside the categories are numerically rated from 1.0 to 5.0 in terms of mechanical system maintenance, service performance, and operation efficiency of the mechanical equipment. The component scores are averaged for each category. These scores are then averaged to give a single score for the whole system. A trial was conducted : ten independent assessors with different years of job experience examined a range of equipment from two major HVAC systems (N = 200). A Cronbach's Alpha internal consistency analysis of the averaged ratings gave a result of 0.76, indicating good agreement between assessors. These data show that apart from being avle to reduce large datasets into a concise summary, the survey technique is robust and internally consistent.