Heating and cooling system installed 1998, had energy audit done a few weeks ago and the audit states 10 SEER for air conditioner and 90% energy efficient for the furnace but my homeowners contract says 80% for the furnace as a homeowner how can I tell which it is? This will make a great difference in whether we qualify for the various energy star rebates our state is offering--should I request that the audit be redone--it cost us $125