started the day with an airplane where the blower was MEL’d for avionics ventilation. Later that day we had a pack (2) controller fault. The mechanic wanted to MEL the pack. The captain and I read over the MEL and it required avionics ventilation to be working normally and the blower MEL required both packs be working normally. We called MCC and they said avionics ventilation was working “good enough” and to continue. If we had problems with what he was saying to call the chief. So we did. The chief said “Don’t you dare fly that way.” We had to overnight and that plane sat in SLC for a couple weeks.