all things being equal..........

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.
Jul 20, 2013
27
upstate ny
all things being equal, do direct vent, closed front propane wall heaters, (the boring plain white looking ones) and direct vent fireplace-type propane stoves (the attractive, cozy-looking ones that resemble a wood-fire) with the same btu rating, give off the same amount of heat, perceived or otherwise? Or in other words, do they both heat just as well, only you are paying more for the latter with the only benefit being aesthetics? Thanks......tony
 
all things being equal, do direct vent, closed front propane wall heaters, (the boring plain white looking ones) and direct vent fireplace-type propane stoves (the attractive, cozy-looking ones that resemble a wood-fire) with the same btu rating, give off the same amount of heat, perceived or otherwise? Or in other words, do they both heat just as well, only you are paying more for the latter with the only benefit being aesthetics? Thanks......tony

All things being equal, a BTU is a BTU. Most are rated at BTU INPUT. In order to determine if two of equal INPUT will give you the same heat, you have to take into consideration the efficiency of the appliance. The INPUT X EFFICIENCY = OUTPUT. Therefore a higher rated BTU may not give you more heat.
For example: 35K X .75 = 26.25K (OUTPUT)
but 33K & .8 = 26.4K (OUTPUT)
Comes down to how efficiently the fuel is burned...
HTH
 
All things being equal, a BTU is a BTU. Most are rated at BTU INPUT. In order to determine if two of equal INPUT will give you the same heat, you have to take into consideration the efficiency of the appliance. The INPUT X EFFICIENCY = OUTPUT. Therefore a higher rated BTU may not give you more heat.
For example: 35K X .75 = 26.25K (OUTPUT)
but 33K & .8 = 26.4K (OUTPUT)
Comes down to how efficiently the fuel is burned...
HTH

DAKSY.......thanks for your response. I did a search and located a heater.......a Napoleon GDS 60-1, that is rated at 35000 btu's. The Empire DV-35 is also rated at 35000 btu's. So to an ignoramus like me, and probably most everyone else that goes to buy a propane heater for supplemental heat, they appear to be about the same, except the "pretty" one (the visible flame Napoleon) costs twice as much as the boring looking, closed front Empire. However, (to further confuse me) on Napoleon's site, they say it is rated at 35000 btu's if top vented and only 21000 for rear vent......quite a difference. The empire's are rear vent as well. Also, I think I read where propane is slightly less in the output department than natural gas, but hopefully not much. This whole selection process is pretty overwhelming unless you are considerably smarter than I am. Also: Napoleon's site rates this stove at "78% steady rate efficiency, and 72% AFUE." Not sure what that means either. Empire doesn't list any efficiency ratings so far as I can see. Thanks for any 'dumbed-down' advice as to the visible flame type direct vent stoves like the Napoleon and the closed front direct vent heaters like the Empire in general. tony
 
DAKSY.......thanks for your response. I did a search and located a heater.......a Napoleon GDS 60-1, that is rated at 35000 btu's. The Empire DV-35 is also rated at 35000 btu's. So to an ignoramus like me, and probably most everyone else that goes to buy a propane heater for supplemental heat, they appear to be about the same, except the "pretty" one (the visible flame Napoleon) costs twice as much as the boring looking, closed front Empire. However, (to further confuse me) on Napoleon's site, they say it is rated at 35000 btu's if top vented and only 21000 for rear vent......quite a difference. The empire's are rear vent as well. Also, I think I read where propane is slightly less in the output department than natural gas, but hopefully not much. This whole selection process is pretty overwhelming unless you are considerably smarter than I am. Also: Napoleon's site rates this stove at "78% steady rate efficiency, and 72% AFUE." Not sure what that means either. Empire doesn't list any efficiency ratings so far as I can see. Thanks for any 'dumbed-down' advice as to the visible flame type direct vent stoves like the Napoleon and the closed front direct vent heaters like the Empire in general. tony

If you really wanna get confused:

http://en.wikipedia.org/wiki/Annual_fuel_utilization_efficiency

http://en.wikipedia.org/wiki/Steady_state_(chemistry)

Basically AFUE is inclusive of highs & lows - Think thermostat kicking on & off...

Steady state is what the immediate efficiency of the fuel consumption is based on input vs output.

I'm sure the chemical engineering guys can get deeper into it, but they've got the sheepskin that says they know what they're talkin about. I don't...:p
 
Hi Tony, don't get too lost on numbers with these mfrs, for direct vent tech around 75-80 percent is the norm for heat efficiencies. (30k btus at 80% is 24K btu output). Based on a 50 duty cycle (running half the time to heat an area) that stove should heat around 800-1200 sqft depending on weather, insulation etc etc. Napoleon vs Empire, you are paying for aesthetics as well. Yellow flame technology is prettier, blue flame technology is clean burning heat. Yellow flame is a little dirtier burn, but prettier. Glowing logs, decorative fronts is all part of the package. Some mfrs have more complicated valves too, to cut different burner levels off if desired (Mendota, Heatnglo, Monessen etc). These features all cost money. There are a lot of quality dv Mfrs out there, too many to name. Direct vent is the way to go though, find a fireplace with the look and features you want and go from there. There are a lot of choices- Mendota, Jotul, HeatNGlo, Travis, Enviro all good brands and much price variance among them. Good luck.
 
I believe that a fireplace is unable to attain the same efficiency as a dedicated furnace/heater like the empire. They both consume the same amount of fuel but the furnace will deliver more btu since the flame is tuned for efficiency which is an ugly blue flame unlike the fireplace's flame which is running richer/yellower/wispier to resemble a wood fire.

If the only priority is max btu per dollar of stove and dollar of fuel then go furnace/heater. Note I am not talking about ducted furnaces but of wall heaters designed for heat.

Other than empire, there are other brands of wall heater that may be even more efficient.
 
Look at the new PV series from Empire. 93% efficiency. The Rinnai's are also nice
 
Status
Not open for further replies.