EdenPURE Heater Systems | Find Out if They Help Lower Heating Costs

[Insanity]

[URL]http://www.edenpure.com/

[/URL]

Curious if these actually help people with heating costs.
Looking for any testimonies from PF members, or close friends of PF members.

While I understand the claims would vary from situation to situation (size of home, apartment vs. stick built house, w/ vs. w/o basement, etc...), was looking at doing some math to see if there is any basis for manufacturer's claim.

I had determined the energy needed to heat a specific volume.
https://www.physicsforums.com/showthread.php?t=450440

In short, 7,764.11 kJ needed to heat 10,000 cf of air from 32F to 70F.

 

[Evo]

Doesn't look good. Consumer reports.

http://blogs.consumerreports.org/home/2010/02/edenpure-gen-3-model-1000-space-heater-consumer-reports-review-amish-heater-.html

 

[russ_watters]

I only see one judgeable claim on the homepage:

You can cut your heating costs, too, using the EdenPURE Infrared Portable Quartz Heater. It can help you to save money on your home heating bill by putting the heat right where YOU need it, so you and your loved ones will be warm and comfortable in your home all winter long, without the high energy costs snowing you under this season.

It is trivially true that if you heat only the room you are in, your heating costs will be lower than if you heat your entire house by the same method. That's not rocket science, nor is it uniquely marketable: that's the entire point of space heaters.

Ultimately what you have here is an electric resistance space heater that, like every other electric resistance space heater inherrently must be, is 100% efficient. The only thing all that unique about it is the slightly more flowery marketing language than typical for something as mundane as an electric space heater. But along with that comes (from the consumer report) lower than average quality for an electric resistance space heater at roughly 10x(!) the price.

 

[Insanity]

Was trying to figure how much cf of gas and how much kWh would be used to provide that much energy.

For gas:
assuming 80% AFUE furnace, plus 30% loss through ductwork.
1 cf of natural gas provides ~1,085 kJ, so 7.158 cf needed to provide 7,764 kJ.

With the 80% AFUE, and 30% loss through the ducts, the cf needed is then 7.158/80%/70% = 12.783 cf.

For EdenPURE, some model info.
Gen4 is rated at 1483 Watts and 5000 BTU. correct if I am wrong the BTU does mean BTU/h. 5000 BTU = 5,275.3 kJ.
so I figured if the heater runs for a hour, it uses 1.483 kWh and generates 5000 BTU, for 3,371.5 BTU/kWh or 3,557.1 kJ/kWh

Then I figured that would require 2.18 kWh, assuming 100% efficiency (no ducts), to provide the same energy.

Here's the thing, the cost of this would vary from provider to provider, so the savings vary if there is any. Even though the gas cost may go down, the electric goes up, though could still be a net savings.

 

[russ_watters]

Well consider that natural gas is a fuel and electricity is an end product generated from the fuel at an efficiency of probably about 40%. So multiply that electrical energy input by 2.5 to get them to an apples-to-apples comparison of the fuel requirement. That'll also help explain why electricity typically costs 3x as much as natural gas for the same amount of energy.

Btw, the natural gas energy conversion is a little more straightforward: a watt is a joule per second, so 1085 kJ / 3600 = 0.3 kWh

Then you just multiply the two gas efficiencies together to get the ratio.

 

[Insanity]

The electricity is billed by the kWh used, regardless as to the amount of whatever fuel used to generate that electricity, is it not?

Gas is charged by thousand cf (Mcf) used.
Electric is charged by kWh used.

So if a 10,000 cf home uses 12.783 cf (0.012783 Mcf) of gas, it is charged for 0.012783 Mcf.
Likewise if it uses 2.18 kWh, it is charged for 2.18 kWh, regardless of the efficiency behind the electrical generation.
The kWh charge though I'm sure accounts for the efficiency, but I don't feel the cost needs to be adjusted again for it.

Yeah, the math stemmed from all the different units some sources were giving.

 

[Evo]

Did any of you read about it in the report I posted? It did go over most of this stuff already.

 

[russ_watters]

I cited it in my first post, yes.

 

[russ_watters]

The electricity is billed by the kWh used, regardless as to the amount of whatever fuel used to generate that electricity, is it not?

Yes, but the fact that it actually uses 3x more fuel is a good explanation for why it costs 3x as much.

 

[Insanity]

Yes, but the fact that it actually uses 3x more fuel is a good explanation for why it costs 3x as much.

Yes, what I meant is if 2.18 kWh are needed to produce 7,764 kJ, I don't to adjust the kWh needed due to efficiency at the power plant. But the Mcf of gas does as the power plant is basically in the home.

I hadn't figured the costs yet, just the Mcf of gas and kWh of electricity required.

 

[russ_watters]

Ok, let's go for the costs then. I just paid my electric bill and my electricity costs $.165/kWh. I live in Southeastern Pennsylvania.

My house uses propane, not natural gas, so we'll do that first for an additional comparison. Last month, propane cost me $2.86/gal. The conversion I can easily get from wiki is 91,690 BTU/gal, which results in $.106/kWh. Now I didn't really like your efficiency numbers, so I'm going to use my own: I have a 95% efficient furnace and well insulated and sealed ductwork that probably loses less than 10% of the energy put into it. So that's $.125/kWh, or 75.5% of the cost of electricity.

For natural gas, again using my efficiencies, I start with the DOE's average residential price from Sept of $15.01 / MCF, since I don't have access to a gas bill. http://www.eia.doe.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm
At 0.301 kwh / CF, that's $.050 / kWh. Applying my efficiency numbers again yields $.058 / kWh or 35.3% the cost of electricity.

Conclusion? I'm getting raked over the coals by my propane heat, but that means that for me, a space heater makes a big difference.

 

[Evo]

Has anyone considered that this is not a good space heater and that there are better ones?

 

[Insanity]

Ok, let's go for the costs then. I just paid my electric bill and my electricity costs $.165/kWh. I live in Southeastern Pennsylvania.

My house uses propane, not natural gas, so we'll do that first for an additional comparison. Last month, propane cost me $2.86/gal. The conversion I can easily get from wiki is 91,690 BTU/gal, which results in $.106/kWh. Now I didn't really like your efficiency numbers, so I'm going to use my own: I have a 95% efficient furnace and well insulated and sealed ductwork that probably loses less than 10% of the energy put into it. So that's $.125/kWh, or 75.5% of the cost of electricity.

For natural gas, again using my efficiencies, I start with the DOE's average residential price from Sept of $15.01 / MCF, since I don't have access to a gas bill. http://www.eia.doe.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm
At 0.301 kwh / CF, that's $.050 / kWh. Applying my efficiency numbers again yields $.058 / kWh or 35.3% the cost of electricity.

Conclusion? I'm getting raked over the coals by my propane heat, but that means that for me, a space heater makes a big difference.

My consumers charges are $0.101278/kWh plus $11.14 fixed charges (system access, etc) and $9.5945/Mcf plus $10.50 fixed charge.

My efficiencies are just that, my efficiencies. I know my furnace is rated at 80%, though I don't have the model specifications handy. My ducts aren't sealed, though my attic is well insulated and no ductwork goes along any exterior wall or the attic. I live in SW Michigan.

Back to my figures of 0.012783 Mcf and 2.18kWh, the charge would be $0.12 for the gas (excluding the fix charges) and $0.22 for the electric charge (also excluding the fixed charge)

At least Michigan has one thing going for the state it seems, the lower energy cost.

PA $0.165/kWh $15.01/Mcf
MI $0.101/kWh $ 9.59/Mcf

Has anyone considered that this is not a good space heater and that there are better ones?

Yeah, I figured it wasn't great, but had to show it to myself.

 

[russ_watters]

Has anyone considered that this is not a good space heater and that there are better ones?

Yes, I said that in post #3...