Hi there, Im having a problem with a group of four split ac units running on r22. They are serving a server room so the heat load is constant. Every so often we get a call to say the temperature of the room has crept up and the customer starts to panic.
Checking the units, im seeing good air off temps of about 8 celcius with the controllers set down to lowest setpoint.
The problem im having is that im getting good cooling of the coils but the units still seem to just barely handle the room.
There is frosting on the suction line back to the accumulator in te outdoor unit and observing very low back pressures of about 2.5barg. This would indicate to me that there is liquid returning to compressor but im sure the air filters are clean and the air flow is good, evaporator is in good condition too??
The 4 units are exhibiting the same symptoms which makes me think the problem is external to them, maybe the load has changed.
Q: If for example, the load was increased beyond design spec of the units, what kind of symptoms would i expect to see?
Could i put the frosting of the suction line down to low gas pressures freezing the moisture in the air, rather than liquid, with high cooling capacity returning and causing the icing?
The idea that the pipe run is too great has been touted but i can see how units that have been installed in a place for 10 years and worked ok, could suddenly have too long a pipe run!?
Could units be installed in excess of their recommended pipe run and run perfectly ok, but just have a shorter life span or will they give trouble from day one?
Sorry for all the questions, its just a thorn in my side at the minute and would love to pin the frosting up to an increased load?? if there is any way this can happen id love to know your thoughts? thanks guys