Lennox's older systems have their own code found between hyphens in the
model number.
211=1.5 ton
261=2 ton
311=2.5 ton
411=3 ton
461=3.5 ton
511=4 ton 651=4.5 ton
So, in the case of your example, you have yourself a 3.5 ton, or 42000 pounds.
can you please tell me what size tonnage is lennox HS9-651-2P and HS9-511-1P
3.5 ton
looks like a 5 ton unit
Hs18-511-3p
what is the tonnage of a cb29m-31-1p
4ton
26.1 kbtu/hr is considered about 2 tons (24 kbtu/hr)
Tonnage means the about something weighs or the amount of BTU’s a unit puts out. . The lennox model HS19-311U-2p is a 2.5 ton unit and has a tonnage of 2.5 BTU's.
1 and a half
1.5 tons
5 ton
4 ton