[ipeng]

I am no expert in this area.
A builder is offering me to either go for the standard "Double Vented 92% efficiency furnace sealed combustion with 2 speed blower fan" or upgrade to a "High Efficiency 2 stage furnace with ECM motor".
Can anyone help explain this terminology. The sales person was not very clear about the differences or benfits of upgrading.

[KISS]

Double vented - combustion air from outside and exhaust from cumbustion to the outside

Two speed - just that. Usually a higher speed for cooling and a lower one for heating. Typical

92% - It's 92% efficient of converting the BTU's in gas to usuable heat

2 stage - Usually means two burners and may also mean different fan speeds for heating. Much quieter. The smaller burner is usually a little more efficient. Especially good if climate is moderate. The high burner kicks in for a number of reasons.

ECM - Buzzword for Electronically Commutated Motor. Allows variable speeds. A little more complex. It's basically a 3 phase motor driven by an electronic circuit from a single phase supply.

Going to a two-stage system depends a lot on climate.

Dual fuel or Hybrid heat is yet another system where a heat pump is combined with gas heat. The heat pump is used when the outside temp is above a certain value.

Also do a search on ERV/HRV

Electronic Air cleaners from Honeywell or Aprilaire can also be considered. The Aprilair 5000 isn't bad, but Honeywell supposedly is a bit better. Allergies/pets/odor/bacteria The 5000 filters are about $30 and last about 6 months. They are huge. Guess about 10" wide and have large pleats.

UV lamps to kill bacteria is another option. Expensive to maintain. Good when humidifiers are used.

[dac122]

The operating costs between these two system are not that much different, but the two stage/VS blow could provide greater comfort as it will run more frequently (at a lower cost). Ask for some operating cost differences, and what if any changes must be made to the duct work.