It depends on the refrigerant's temperature glide and the system's operational state during the leak:
• Running or Frequently Cycling Systems: Recent studies show that when a system is running or cycling normally, the moving refrigerant prevents significant fractionation. For low-glide blends, fractionation is minimal under any condition. In these cases, you can safely repair the leak and top off the charge directly.
• Idle Systems (Worst-Case Scenario): If a high-glide system has been shut down for an extended period (over 24 hours) and loses a substantial amount of refrigerant (around 50%), significant fractionation can occur. This alters the blend's properties. For these situations, it is best to recover the remaining charge and perform a fresh recharge.
• Historical Guideline for High-Glide Blends: Past research on stationary containers showed that high-glide blends could be topped off up to five times before fractionation severely degraded performance, though direct recharging of running systems is now preferred.