How much freon is needed for a 1.75 ton a.c. unit.?

Question

where weather is avg. 94, air handler is small zero clearance type.

Answer 1

You don't say how old the unit is.  If you can still read it, somewhere on the outside unit is a list of the specs.  It may be inside the cover plate giving access to the wire chase.  There will be a spec for the number of pounds of freon and the line-set length (distance of copper tubing) used for the spec.  Less tubing equals less freon, etc.  Now, just adding freon without gauges is dangerous.  Too much or too little can burn up the unit.  If the unit is low on freon, where did it go.  You probably have a leak.  So, you have a decision to make:  Add freon when needed or repair or replace the leaking part.

Answer 2

An air conditioner will require the same charge if the weather is 74 average.

An air conditioner is charged by subcooling and superheat and the wet bulb inside temperature is needed.

How long the line set is will make a difference as will any liquid line filter.

On average probably 3&1/2lbs.

Improperly charged systems affect both evaporator and condenser pressure,causing coil temperature problems and poor compressor performance.If the charge is not correct,compressor failure could result.