Alright custy wanted to try a merv 13 in their Liebert due to covid. But, I'm not gonna just throw in a filter without checking performance of the unit. Base line test with a merv 8 shows 5.4 amps on the blower motor, merv 13 also 5.4 amps. Pressure difference across the filter (remember that Lieberts move more air than a standard system in most cases) with the merv 8 was 0.01"wc and pressure difference with merv 13 was 0.05"wc. At this point I'm good, next visit will give some indication as to how fast the filter loads up and another set of readings will be taken. The other thing that might effect the readings is the fact there is no duct work to create the ballooning effect in a duct system to capture proper pressure drop. Basically this system is zero static.

Posted by HVAC Know It All at 2021-04-01 15:19:13 UTC