What is the difference between the SEC99AB-18 and SEC99AB-18C

the 16x25x5 air filter handles up to 1600 CFM of airflow

or blowing off the thermocouple

reducing unburned fuel accumulation

the kit provides the necessary spring and orifice components to maintain consistent LP manifold pressure

Copeland Comfort Control (Alco) 066146 Expansion Valve 30067439-890 What is the difference betweenThe Copeland Alco TFES 12 ZAA is a high performance R410A thermal expansion valve designed for large scale residential and commercial air conditioning systems. Engineered with a 12 ton capacity and a straight through body configuration, this TXV features 5 8" x 7 8" ODF sweat connections for secure, leak free integration into the liquid line. The externally equalized design ensures precise superheat control, compensating for pressure drops across the