The HK2000 Fresh Air and Economizer panel provides intelligent and economical control of residential and light commercial heating and cooling systems. The HK2000 can control up to three (3) 24 VAC dampers: Outside Air, Return Air, and Exhaust Air. The HK2000 is suitable for all new construction and most retro-fit applications. In the Fresh Air mode, the HK2000 has the flexibility to bring in as much, or as little Fresh Air as needed. The cycle timer is adjustable from 0 (off) to 12 cycles (continuous) per hour. When the cycle timer is set to 4 cycles per hour, representing 20 minutes of Fresh Air, the HK2000 will activate the Fresh Air mode for 5 minutes every 1/4 hour (or every 15 minutes). The Economizer mode of the HK2000 allows for the use of outside air to satisfy the need of indoor cooling. This form of "free cooling" is monitored and controlled using several methods.