Final answer:
High Efficiency furnaces can achieve efficiencies of 95% to 98% and have two heat exchangers, use a PVC pipe to carry away flue gases, and use an induced draft fan.
Step-by-step explanation:
High Efficiency furnaces:
(e) All the above
High efficiency furnaces can achieve efficiencies of 95% to 98%. They have two heat exchangers, use a PVC pipe to carry away flue gasses, and use an induced draft fan to help with the combustion process.