The need for more CFM due to an upgrade on an Air Conditioning System.
We had never experienced issues with an upgrade until the summer of 2022. We replaced only the air conditioning components of an oil furnace system. We replaced an old R-22 refrigerant system, which included the condenser (outdoor unit) and evaporator coil (indoor unit). The new system included new components of the same indoor and outdoor units but design to work with 410A refrigerant.
After the installation, during the startup and testing of the new system components, we noticed the need for more CFM (air flow). This was very frustrating to realize this after all the work to get the system install and the hope to satisfy the customer.
We then spoke to the ThermoPride the manufacturer of the oil furnace to understand a little more on what may be the reason the new system with the same tonnage and design specs did not work properly. The manufacturer advised on the need for more power due to the 410A refrigerant pressures. They also stated the furnace did not have the capacity to output the air flow needed to remove the heat load from the evaporator and therefore freezing the coil.
ThermpoPride advised us on upgrading the belt driven fan blower to a direct drive. The conversion was not bad to implement, and the unit was finally operating as per design. This proved that no matter how long you practice on the field there is always room for growth. This was a great lesson and experience.
Regards.
wtech22 heating and cooling