What is required when installing a 90% furnace that is not required for an 80% furnace?

What additional requirements are needed for installing a 90% furnace compared to an 80% furnace?

What specific components are necessary for a 90% furnace installation that are not needed for an 80% furnace?

Answer:

A 90% furnace, unlike an 80% furnace, requires a condensate drain to remove the significant amount of condensation it produces. It also requires a PVC venting system because it expels cooler exhaust.

When installing a 90% furnace, a key requirement not necessary for an 80% furnace is a condensate drain. The term "90% furnace" refers to a high-efficiency furnace - it converts 90% of the fuel it burns into heat for your home. It also produces a significant amount of condensation due to the cooling of exhaust gases, and this condensation needs to be removed to prevent harm to the system. Thus, it requires a condensate drain system, whereas an 80% furnace does not produce significant condensation and hence does not need this drain.

In addition to the condensate drain, a PVC venting system is also required for a 90% furnace. This is because a 90% furnace expels cooler exhaust compared to an 80% furnace, which means it needs a different type of venting system to safely remove the exhaust gases from your home. The PVC venting system is designed to handle the cooler exhaust produced by the high-efficiency furnace.