The answer to your question is answer choice D.
After installation of a field-piped R-410A split heat pump, the unit should first be:pressurized with nitrogen then leak checked.Heat Pumps that have been retrofitted from R-22 to R-407C should be leak checked with:pressurized nitrogen.The EPA regulations require that leaking commercial or industrial process refrigeration equipment must be repaired when the leak rate exceeds ______ of the charge per year.35%
It says to find a picture about Black History like maybe Martin lither king jr? Then say why you pick this person and what he does.
