There are a few differences to be aware of when deciding between a high efficiency and standard efficiency furnace, if you have the option of being able to decide. The obvious difference is… their efficiencies!
Furnace Efficiency (AFUE) – Standard models utilize 80% of the natural gas that they consume to actually heat your home, the other 20% is essentially wasted via exhaust. High efficiency furnaces from York utilize 95.5% to 98% depending on the model.
Exhaust Ventilation – For the most part, in the Rochester area, standard efficiency furnaces are vented through your chimney via a metal pipe. High efficiency furnaces are a bit different though. They are vented through PVC (plastic) pipes that will typically exit through the side of your home. Location for this exhaust exit is critical, and unfortunately we see a lot of installers mess this up. Getting this wrong can cause major reliability / no heat issues, and can also violate actual safety regulations.
Water / Condensation – Standard furnaces have no water / drainage to worry about. Any drainage you have in a system like this would strictly be from the air conditioning system. High efficiency furnaces generate condensation in their exhaust, which is actually acidic. This must be drained safely away from the furnace. If a drain is not available, a pump must be installed as well. This isn’t a big deal, but it is just something to know.