hvac

Looks like my central heatpumps outside fan died it's been sounding rough this year so no surpris. I noticed the fan was of particularly terrible design. 2 blades stamped flat sheet metal. Like it's the 1970s or something. $15 box fans from Walmart have balanced airfoils shaped for reduced...

From my understanding old R22/12 equipment used Mineral, which seems to mean non synthetic base 3 or less or Alkylbenzene base. New R410a equipment seems to be POE in hvac and PAG in 134a/automotive, with R1234 using POE sometimes.... Apparently they don't mix well with non chlorine based...