Englander 25pdvc vs 25 pdv.. how does the extra heat happen?

[MIkeCInMaine]

Does anyone know exactly how the full size Englander 25pdv produces twice as much heat as the compact 25pdvc version if the auger motors and control boards are the same exact parts? I know that the smaller stove has a lower CFM blower (130cfm vs 250cfm) but if thats the only reason for the decreased heat output it would stand to reason that both stoves are burning the same amount of fuel and the C version is just letting more heat go out the chimney. That's not possible if both stoves have the same 78% efficiency

Mike C in Maine

 

[DrewBoogie]

From what I remember looking at them in Lowes side by side, the burn pot is bigger in the PDV.

 

[acammer]

The control board has different "Modes" for different stoves. Those modes control the curve for the fuel and air, start up procedure, etc, and are not the same for every stove. I'm sure the fueling curves for the two stoves are significantly different on the top end.

 

[Cedarjunki]

Does anyone know exactly how the full size Englander 25pdv produces twice as much heat as the compact 25pdvc version if the auger motors and control boards are the same exact parts? I know that the smaller stove has a lower CFM blower (130cfm vs 250cfm) but if thats the only reason for the decreased heat output it would stand to reason that both stoves are burning the same amount of fuel and the C version is just letting more heat go out the chimney. That's not possible if both stoves have the same 78% efficiency

Mike C in Maine

This is my take on the subject...
Just because the pvdc can handle running in the pdv's mode C doesnt mean it was entirely designed to do so. Having the larger stove allows for a safer higher continuous burn.
I am willing to bet a pdv will outlast a pdvc running the same mode and heat setting over time.

 

[DrewBoogie]

The control board has different "Modes" for different stoves. Those modes control the curve for the fuel and air, start up procedure, etc, and are not the same for every stove. I'm sure the fueling curves for the two stoves are significantly different on the top end.

Good point, the bottom 3 numbers are set to different factory defaults on each model despite the board being the same.

 

[Chrisnow86]

The over all size of the heat exchanger is a lot bigger on the pdv so it's built to handle more fire..

 

[MIkeCInMaine]

The control board has different "Modes" for different stoves. Those modes control the curve for the fuel and air, start up procedure, etc, and are not the same for every stove. I'm sure the fueling curves for the two stoves are significantly different on the top end.

Ah.. my 25 pdvc was made in 10/2003. I bet it has an older style board that was specific to the pdvc. It doesn't have an igniter hookup (I use a self-lighting propane torch).

So the answer to my question is that these "modes" on the newer boards change the feedrate. That is, a heat setting of "9" will give a different feed rate depending on the board's mode.

Funny thing is that my old 25 pdvc seems to put out more heat than a used 25 pdv that I picked up about 6 years ago. I ran the newer larger stove for the past 5 years and now I am switching back to the pdvc. My house is passive solar and super insulated (in Maine) so I only burn about 1.5 tons per year (2500 sq ft).

Thanks everyone!

Mike

 

[Cedarjunki]

Ah.. my 25 pdvc was made in 10/2003. I bet it has an older style board that was specific to the pdvc. It doesn't have an igniter hookup (I use a self-lighting propane torch).

So the answer to my question is that these "modes" on the newer boards change the feedrate. That is, a heat setting of "9" will give a different feed rate depending on the board's mode.

Funny thing is that my old 25 pdvc seems to put out more heat than a used 25 pdv that I picked up about 6 years ago. I ran the newer larger stove for the past 5 years and now I am switching back to the pdvc. My house is passive solar and super insulated (in Maine) so I only burn about 1.5 tons per year (2500 sq ft).

Thanks everyone!

Mike

If in fact the board is still the original old style that may be true.
An updated board will have ignitor and vacuum terminals.

 

[Chrisnow86]

Doesn't the pdv hold more fuel too?

 

[Cedarjunki]

Doesn't the pdv hold more fuel too?

I averaged about a bag and half in mine.

But the biggest factor here i think is the older stoves were built to HEAT with less regulations on emission standards.

 

[Chrisnow86]

Ya like the holes allowing air around the fire in the burn pot... Epa kills everything

 

[MIkeCInMaine]

Ya like the holes allowing air around the fire in the burn pot... Epa kills everything

doesn't more air make for more complete combustion?

 

[MIkeCInMaine]

If in fact the board is still the original old style that may be true.
An updated board will have ignitor and vacuum terminals.

I know I don't have the ignitor terminals (I checked today) but I do have at least a combustion blower vacuum switch.

 

[Cedarjunki]

doesn't more air make for more complete combustion?

If the air was passing thru the fire and not around it yes.

 

[MIkeCInMaine]

ah.. in mine it comes in the pipe and comes up under the plate with the little holes in it.

 

[Cedarjunki]

ah.. in mine it comes in the pipe and comes up under the plate with the little holes in it.

They added larger holes above the plate on the sides.

 

[Cedarjunki]

I know I don't have the ignitor terminals (I checked today) but I do have at least a combustion blower vacuum switch.

Pray your board never goes bad. The replacement will be the newer programming

 

[jjones139]

If I may ask a question while we are discussing both Englanders...... Would the PDV room blower work in a PDVC? I have both stoves and have always noticed a big difference just with the room blower.

 

[Cedarjunki]

If I may ask a question while we are discussing both Englanders...... Would the PDV room blower work in a PDVC? I have both stoves and have always noticed a big difference just with the room blower.

May not have enough room for the larger blower.

 

[MIkeCInMaine]

May not have enough room for the larger blower.

I thought about the same thing..

The PDV blower is about twice the CFM output and its physically larger. It also draws more power.

Not only is there possibly not enough space for the larger blower in the PDVC, but the air channels are smaller and you might get a lot more noise, even whistling. You could run the blower on a slower setting.. but then what's the point, right?

You might also move too much air thru the system, thereby over-cooling the exchanger and leading to more soot buildup and poorer draft.

The bearings in my convection blower motor in my PDVC were just about frozen when I took the stove out of storage. It's the kind of motor you can disassemble. Got some spray dry lube into the bearings and she's like new - for now

 

[Chrisnow86]

So that tells me with the smaller exchanger and less CFM blower, when you run the pvdc in mode C your sending a lot more $ out your exhaust pipe...

 

[acammer]

So that tells me with the smaller exchanger and less CFM blower, when you run the pvdc in mode C your sending a lot more $ out your exhaust pipe...

That's likely true - you're at the very least past the point of peak efficiency. But, for some of us we're after getting every last BTU possible out of our stoves to meet demand on the real cold days, and we'll push right past peak efficiency to go for peak output. I figure I've got a high limit in the exhaust, so until I get to the point where I'm tripping that switch, on the real cold days I'll push my stove to give me everything it can give - even if that means I'm pushing some heat right out the exhaust. I've taken steps such as temporarily closing up my air wash vents so that I can pull more air through the burn pot, and thus trim in even more fuel.

I averaged about a bag and half in mine.

But the biggest factor here i think is the older stoves were built to HEAT with less regulations on emission standards.

And there you have it - those old stoves really could push the heat! The old Dynasty I had could eat 10lbs/hour. That exhaust would get pretty hot - but man would she push out the heat to the room!