MALB_2014 with 1-21 Revisions

Conducting Measurements of Radon and Radon ANSI/AARST MALB-2014 with 1/21 Revisions Decay Products in Schools and Large Buildings 46 HVAC GROUP DESCRIPTIONS Page 2 of 3 Group 1: BASIC HEATING AND COOLING (HAC) Dedicated system(s) that do not supply additional outdoor air for ventilation. HAC Systems: Many buildings have forced-air heating and air conditioning (HAC) systems. Supply and return ducts distribute air around the building. Ductless Systems: Some rooms or dwellings do not have ducted forced-air distribution. • Hot and Cold-Water Circulation (sometimes referred to as “radiator" systems). • Window Air Conditioners. • Wall or Baseboard Heating/Cooling Systems. • Ductless Split Systems with one unit for cooling and another unit for heat (i.e. Window AC for cooling and Baseboard or Wall units for heat). Group 2: MULTI-ZONE SYSTEMS Multi-zone systems are those where different air handlers or systems are employed and independently controlled for different areas within the same dwelling or common use area of a building. Radon concentrations can vary from room to room based upon variances in system operations.