11 SPACE HEATING AND COOLING SYSTEMS, COMPRISING HEAT PUMPS, BLOWER COILS, ELECTRIC HEATING STRIPS, CONDENSING UNITS, RETURN AIR BOXES, DUCTING, FITTINGS AND CONTROLS, SOLD AS A UNIT; SPACE HEATING SYSTEMS, COMPRISING BOILERS, BASEBOARD AND CONTROLS, SOLD AS A UNIT; WATER HEATING SYSTEMS, COMPRISING BOILERS, WATER STORAGE TANKS AND CONTROLS, SOLD AS A UNIT; AND COMPONENTS OF SAID SYSTEMS