comparison 2 ton unit with 2.5 ton drive
2 ton unit with 2 ton drive ,compare to 2 ton unit with 2.5 ton drive !
which one will have a better performance !!
i will say 2 ton unit with 2.5 ton drive,
i wanna know if anybody agree with me or it just me .
Depends on the application and the equipment.
There are times, especially in retrofit applications where the existing duct system can't be accessed, that a larger blower is needed just to get the required airflow at higher than normal static pressures.
I had a job a couple of weeks ago where we had to replace 2 systems in a 2 story house. 2.5 ton system upstairs, 2.5 ton system downstairs.
Same outdoor unit and coil used for both, but used a furnace with a 3 ton drive for downstairs because there were only two 10" ducts coming up through a chase into the attic to feed the downstairs duct system. Ended up with .85" wc ESP to move about 900 cfm on medium high blower speed for downstairs.
We used a furnace with a 2.5 ton drive upstairs that ended up moving 970 cfm at .55" wc ESP on medium high blower speed.
There are also some pieces of equipment from some manufacturers that have weak blowers. Sometimes it is so bad that once you subtract the PD for the evaporator coil and filter, there isn't enough available static pressure from the blower left to design a duct system around.
In those cases you would have to choose a different piece of equipment with a more powerful blower.