How do I work with a High Efficiency / Oversized Evaporator in mQ?
A high efficiency or oversized evaporator is elected when the
evaporator is larger than the condenser (ie. the condenser is a 3-ton
and the evaporator is 3.5 ton) to drive up the suction pressure and the
efficiency by decreasing the compression ratio. This is often done to
increase SEER. That said, many times it is also done to decrease static
pressure drop across the coil, and the airflow is reduced to 350
CFM/ton to take the suction pressure back to typical. If you are
shooting for the higher SEER and higher suction, go to the main settings menu (the gear icon) and turn on "Advanced Targets". This will add two data fields to the Profile page; Desired "Nominal Airflow" (not actual), and an on / off switch for "High Eff. / Oversized Evaporator". Turning on the Oversized Evaporator setting will compensate the low side pressure target for a 1/2 ton oversized evaporator.