In today’s market, a lot of contractors will use one manufacturer’s condensing unit and another manufacturer’s evaporator coil. You should check to see if these are a match on the AHRI web site so it does not create a problem later on.
A lot of 13 SEER units today can still use an orifice metering device or a TXV. The coil manufacturers will usually put in a nominal tonnage orifice in their coil for the size they rate it at. If you are putting in a “matched” system (ie. 2 ton condenser with a 2 ton coil) the orifice will be properly sized for the condenser/coil match. However, when you are mix/matching the condenser and coil (ie. a 2 ton condenser with a 3 ton coil), the orifice needs to be changed to match the size condenser you are installing. In this example the match would require changing the 3 ton orifice that comes in the coil to a 2 ton orifice. Without the proper orifice, you could over-feed the coil, reduce super-heat, and cause liquid slugging back to the compressor (and compressors do not like liquid).
My personal preference, when mix/matching a condenser and coil is to use a TXV for better refrigerant and capacity control. Keep in mind, that if you do use a TXV, don’t forget to add a start assist kit to the condenser or you may have nuisance lock-outs or breakers tripping..
We are a York distributor but we also sell ADP coils. This posting came about from questions we have received on this very subject. For our mix/match combination, we put together the attached sheet to show which ADP orifice or TXV should be used for specific tonnages. Keep in mind that you also have to match the refrigerant type along with the tonnage to select the correct orifice or TXV. Hope this helps anyone using ADP coils.
For other brand after-market coil manufacturers, you can check what orifices they use so you have the proper orifice for your application.