Four riser heating and cooling system

A unit for heating or cooling air in a room of a multistory building comprising:

• a housing having a first and a second compartment;
• a first air inlet in said first compartment;
• a first air outlet in said first compartment;
• a first heat exchanger in siad first compartment;
• first circulating means in said first compartment for drawing air into said first air inlet, flowing the air through said first compartment in a path passing over said first heat exchanger, and discharging the air through said first air outlet;
• said first heat exchanger including two substantially vertical risers extending the length of said housing for direct connection to the risers of corresponding units located on adjacent floors of the building to form a continuous flow circuit for a first heat exchange fluid;
• a second air inlet in said second compartment;
• a second air outlet in said second compartment;
• a second heat exchanger in said second compartment;
• second circulating means in said second compartment for drawing air into said second air inlet, flowing the air through said second compartment in a path passing over said second heat exchanger, and discharging the air through said second air outlet;
• said second heat exchanger including two substantially vertical risers extending the length of said housing for direct connection to the risers of corresponding units located on adjacent floors of the building to form a continuous flow circuit for a second heat exchange fluid;
• and
• a single thermostat means connected to said first and second circulating means for operating said first and second circulating means responsive to the temperature in the room whereby selected stories of the building can be heated while others are simultaneously cooled.