Propane Furnace

[hobbyheater]

My mother in law is 100 years and still heats her house with wood! ( She still drives and works 3 half days a week) I'm 77 and have all the good toys for getting firewood! But putting up 10 to 15 cords for her and 4 for myself is becoming daunting!
The panel for the house is only a 100 amp service that is pretty much maxed out.
The wood furnace is approaching the end of its life.
We have been considering a propane furnace but don't know much about them. The only propane furnace I've seen was in my wife's Grandfather's house and consisted of a flame bar ( much like you would see in a oven) and the thermostat turned on the gas when heat was called for and a limit switch in the plenum turned on the blower.
I would like to know what the cutting edge now consists of.

 

[Whitenuckler]

My mother in law is 100 years and still heats her house with wood! ( She still drives and works 3 half days a week) I'm 77 and have all the good toys for getting firewood! But putting up 10 to 15 cords for her and 4 for myself is becoming daunting!
The panel for the house is only a 100 amp service that is pretty much maxed out.
The wood furnace is approaching the end of its life.
We have been considering a propane furnace but don't know much about them. The only propane furnace I've seen was in my wife's Grandfather's house and consisted of a flame bar ( much like you would see in a oven) and the thermostat turned on the gas when heat was called for and a limit switch in the plenum turned on the blower.
I would like to know what the cutting edge now consists of.

If you have ducts, then you could get a ducted heat pump system with electric backup. That give you AC also, and the electric is for those really cold days. That combined with a wood stove or pellet stove would be good. 100A service would be too small though. A panel upgrade would be required.

 

[Murray01]

Can’t help with the cutting edge technology on the propane furnace.

Our previous house had a natural gas furnace and only required 110 volts to run the blower motor. I ASSUME propane would be the same.

 

[djlew]

I was on the fence with propane before I realized natural gas was an option in my area. Just to make sure I had heat in time, my installers basically said that you can install the natural gas furnace and convert to propane if need be. I don't think the conversion kits are too much money, but I am unfamiliar with rules/regulations for conversion and if it is a viable option for most NG furnaces. I have a full Trane system now, 2 stage NG furnace that according to them could convert. I'm pretty sure if you look online the NG furnaces will tell you if they are convertible on the manufacturer's website.

My old system was what @Whitenuckler suggested, but since my house was fully electric when it was built I didn't need a panel upgrade. I would also recommend a better heat pump than what I got if you went that route, which basically would freeze up under 35 degrees Fahrenheit and the electric strips would absolutely eat up electricity. Granted, my wood stove does not heat up everything from cold start efficiently lol, so in conjunction with a bigger stove would help. Some days I was eating up to 170kwh in one day. It was crazy.

 

[Whitenuckler]

Can’t help with the cutting edge technology on the propane furnace.

Our previous house had a natural gas furnace and only required 110 volts to run the blower motor. I ASSUME propane would be the same.

I'm sure you could run it on with 5A, 120V. I had some measurements from my NG furnace as I was ready to use an inverter.

 

[Whitenuckler]

My mother in law is 100 years and still heats her house with wood! ( She still drives and works 3 half days a week) I'm 77 and have all the good toys for getting firewood! But putting up 10 to 15 cords for her and 4 for myself is becoming daunting!
The panel for the house is only a 100 amp service that is pretty much maxed out.
The wood furnace is approaching the end of its life.
We have been considering a propane furnace but don't know much about them. The only propane furnace I've seen was in my wife's Grandfather's house and consisted of a flame bar ( much like you would see in a oven) and the thermostat turned on the gas when heat was called for and a limit switch in the plenum turned on the blower.
I would like to know what the cutting edge now consists of.

I don't have any ducts here, but I did look into getting a propane stove or heater for the basement. There is no natural gas here. The costs were going to be ongoing, as you need to rent the tank. If you buy the tank, then it needs to be re-certified after 10? years, and any issues with the tank are your to hire someone to fix. The contracts for gas supply might have a yearly charge, a minimum charge ect. It is nice, but like everything else, expensive to own and operate. The other thing though is you can have multiple loads like the furnace, space heater, fireplace, BBQ, outdoor fireplace ect.

 

[brenndatomu]

putting up 10 to 15 cords for her and 4 for myself is becoming daunting!

10-15?!
What about a more efficient wood burner for her?

I would like to know what the cutting edge now consists of

Cutting edge (at least mainstream) is two stage burners...and most of those have ECM variable speed blowers on them.
2 stage is nice because it comes on low and doesn't cycle on/off as much (which she would hate the hot/cold cycling of a single stage, being she is used to long/steady wood heat) ECM blower is nice because it comes on/off so slowly that you don't even notice it running, plus it varies blower speed with the 2 stage gas valve output too. If stage one is not enough BTUs to keep up, then the furnace will kick to high. Many people claim it saves gas over a single stage furnace...more comfortable for sure!
They have been around for long enough now that prices have come down, and the bugs worked out.
You can get propain, or NG, and most are convertible with a simple gas orifice swap (some even come with both)
This will be a high efficiency furnace 95% or so, and condensing, so it pulls combustion air in through a PVC pipe, and exhausts out through the same (sometimes a pipe inside a pipe, so only one hole to outside)

 

[gthomas785]

Most gas burners can be converted. To convert any burner from NG to propane you need to swap the orifices, and readjust the pressure at the gas valve (which may require swapping the valve depending on the type).

 

[Highbeam]

Modern propane furnace exhausts even horizontally with small PVC pipe. This leaves your wood flue unused. I would plan on replacing the wood furnace with a modern one and a propane furnace.

 

[hobbyheater]

10-15?!
What about a more efficient wood burner for her?

Cutting edge (at least mainstream) is two stage burners...and most of those have ECM variable speed blowers on them.
2 stage is nice because it comes on low and doesn't cycle on/off as much (which she would hate the hot/cold cycling of a single stage, being she is used to long/steady wood heat) ECM blower is nice because it comes on/off so slowly that you don't even notice it running, plus it varies blower speed with the 2 stage gas valve output too. If stage one is not enough BTUs to keep up, then the furnace will kick to high. Many people claim it saves gas over a single stage furnace...more comfortable for sure!
They have been around for long enough now that prices have come down, and the bugs worked out.
You can get propain, or NG, and most are convertible with a simple gas orifice swap (some even come with both)
This will be a high efficiency furnace 95% or so, and condensing, so it pulls combustion air in through a PVC pipe, and exhausts out through the same (sometimes a pipe inside a pipe, so only one hole to outside)

To be this efficient with a two stage burner and ECM blower these units must have a computer running things?

 

[brenndatomu]

To be this efficient with a two stage burner and ECM blower these units must have a computer running things?

Oh absolutely...they all do...its been a looong time since a gas/LP hasn't been computer controlled. The good thing about it all is that the board is usually pretty reliable (at least for the burner control...can't say for sure on the ECM blower motor)
The most common thing needing replaced would be the igniter, but those usually last quite a while too.
I hear that the heat exchangers cracking is a problem on the newer NG/LP furnaces too...but I wonder if a 2 stage model would last longer, since the temp cycles would be a little less severe?

 

[hedge wood]

I have been installing what I call 90 Plus natural and LP furnaces for twenty five years. Some of them had a PSC motors and were single stage rated at 90 or 92 percent. Ones with two stage and ECM motors are rated normally at 96 percent. They all come from the factory natural gas but switching to LP is quick and normally fifty dollars or less. In twenty five years I have never had to replace a board in one that I installed. I have had to replace one ECM motor and that was the one that is in my own shop and was twenty five years old and was one of the early ECM motors. A couple ignitors. I normally install a middle of the road brand that is Goodman and I haven't had any cracked heat exchangers on them but have replaced some on some other brands. Years ago Trane and Lenox had some issues. 90 plus are great for refits in old house with bad or no chimney's. I received a call a couple weeks ago from a women I put a 96 ECM two stage LP furnace and central AC back in 2018. It was a friend of a friend as these folks are fifty miles from me and in the middle of no were. No one out of the city wanted to go out there. She had no heat that morning and wasn't happy. Went threw a few things on the phone with her no luck. I will try to make this short and to the point. This lady had mice living in the basement and in the burner box section of the furnace. They had a condo in there and finally had completely chewed threw the two wires going to the igniter. Its probably good the mice had disabled the furnace as there was so much mouse nest in there I couldn't believe it hadn't caught the furnace on fire and possibly burned the house down. I did some rewiring to get the furnace going for a few days until it warmed up some and we could get set up with some aux heat so I could replace the furnace. The wiring was bad and you can't buy a new harness for the furnace. Wiring harness's aren't something that normally wears out in a furnace.

 

[hobbyheater]

Oh absolutely...they all do...its been a looong time since a gas/LP hasn't been computer controlled. The good thing about it all is that the board is usually pretty reliable (at least for the burner control...can't say for sure on the ECM blower motor)
The most common thing needing replaced would be the igniter, but those usually last quite a while too.
I hear that the heat exchangers cracking is a problem on the newer NG/LP furnaces too...but I wonder if a 2 stage model would last longer, since the temp cycles would be a little less severe?

Thanks for the reply ,its means getting a new backup generator for power outages! ( Honda eu 7000)

 

[hobbyheater]

ECM blower what does it stand for?

 

[Whitenuckler]

ECM blower what does it stand for?

Electrically Commutated Motor. We used to study DC motors in my day. They had commutators and brushes.

 

[brenndatomu]

Infinitely variable speed is what an ECM does for you...pretty slick.

 

[Whitenuckler]

ECM blower what does it stand for?

Here is the complicated answer: They used to fail quite often when they replaced AC Induction motors, but I'm sure they are fine now.

https://eepower.com/technical-articles/what-is-an-electronically-commutated-motor-ecm/#