Up to 2.5 Tons
3 1/2 TONS
based on this Lennox nomenclature explanation: Lennox_Model_and_Serial_Nomenclature.pdf the "-65" refers to 5 tons.
3
1.5 tons
No we don't really care about it but it is a scam
3 tons
2.5 tons
26.1 kbtu/hr is considered about 2 tons (24 kbtu/hr)
HS19 is a High Side condensing unit series 19 rated at (511) 51,000 BTU/hr or 4 tons.
One can purchase Lennox parts from the Lennox distributor directly through their online website. You can also purchase Lennox parts are many different online retailers, or use eBay to bid on them.
That is a series number...no capacity. The next set of numbers give you the capacity. Generally, Lennox unit numbers equate to their capacity divided by 1000. IE: XXX90 has about 90,000 BTUH capacity...7.5 tons.