80% gas furnace versus 90% gas furnace

By the time you factor in the initial costs, actual lifespan, and maintenance costs of a 90% furnace, I doubt most would ever recover the costs. The safe bet is still with an 80% furnace.

Great Info, Thanks

I have not seen a new 80 percent in years.that draft inducer on that 80 looked different then the older ones .great video man,your videos have so much more important information then any of the other hvac youtube guys

Love the HE furnance along with the humidifier. The temperature is always steady with no spikes in temperature like my old furnance. I would definitely buy another one. Also, i would recommend buying a water pump instead of using a pvc pipe for drainage. It just looks nicer and the pvc pipe out of the way.

thanks bro, down here in the florida swamp

Great stuff

Both furnaces burn 100% of the fuel. If they aren't the mixture is set too rich and the result is incomplete combustion, which will soot up your flue and pollute. The difference is that an 80% furnace will transfer (wait for it) 80% of the heat through the heat exchanger exchanger and into the structure and a 90% efficient will transfer 90% of the heat. That means that lost "waste heat" sent out the flue is 20% and 10% for the respective furnaces I have an 80% furnace in my 14 year old house. It looks basically brand new. My aunt had a 90% furnace that was about the same age. She had to replace her rusted out junk earlier this year. Yah she saved money on fuel, but did she save $4k on fuel in that time and was she able to save that money to buy the replacement furnace? The added complexity and cost just aren't a good economic and possibly not a good environmental tradeoff IMO.

I joined. Question; what would require that a high efficiency furnace go from 2” exhaust to 3” pipe? The install manual lists both with :” allowing longer runs.

Electric wall heaters are way more cost effective over the lifetime of the home. They last way longer and after the initial installation they cost only $200 to completely replace. No hvac gouging required

Thanks for the video! I've never heard anyone say "propane is the worst kind of fuel". I'm in a semi-rural area. All of my customers (mobile home, park model RV, and RV) rely on propane for heat and cooking. I appreciate your info on 90% er's. Eventually even my mobile units will go that direction.

Knoxville TN

I have a builders grade York furnace installed in my attic. That freaking condensate line freezes every winter. I had to run a pipe heater wire. So mad at the builder for not knowing don’t use 90% in attics

There such a thing as "good enough". I have elected to install a new 60k btu , 80% furnace in my home to replace the existing 80k btu. Calculations show that the old furnace was too big for my 1600 sf home here in Portland, Oregon's relatively mild climate. The payback period here would not justify the more expensive units. Gas and electric are relatively inexpensive in the Pacific North-West. Of course, that could change, but I doubt I would be in this house for more than 10 years maximum. The new furnace requires minimal alterations to install, and in general, less high tech to go wrong and cost more to repair in the future.

Excellent video with a lot of useful information. I currently have a 100,000 btu gas furnace which I need to replace due to 3.5 ton compressor going bad along with 400sqt addition which bring the house to around 1800sqt with 10 big windows. What size btu furnace and compressor would you ruffly recommend for the size house. I think the unit is 28+ years old.

I’m not sure where you’re buying B Vent pipe but I paid $29.97 for a 5 foot piece of 4” B Vent pipe at Home Depot when I installed my 80% furnace. I’m pretty sure that contractors can get a better price than that at the supply house.

6 pm Oklahoma City

Thanks so much, I do have a Trane X90 80,000BTU single stage and my house is a high ceiling and colonial style 2500sqf, one of my rooms upstairs has low heat, do you think 2 stage furnace will be good for me

On a multi stage furnace, how does it know at what setting, high, low or variable? I'm not in the HVAC business but am looking at a furnace replacement and would like to make an informed decision. Thank you.

The fact is that 10% extra energy saving adds up over time after 20 plus years the only guaranteed thing is fuel cost only go up

90% furnace has 2 heat exchangers