Is there an equation to compare heating costs of propane versus electricity? Being an empty nester, I have a house that used to have four kids and two parents down to only the two parents, so I'm wondering if it's efficient to just heat the bedroom and letting the rest go cold (SF Bay Area temps).
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Both will heat a room but one is 1500 Watts max at about 25 cents per killowatt hour while the other is 9000 BTU max at ~$4 per gallon propane.
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Initial hardware costs were a bit more for the propane than electric.
Initial cost for the electric heater was $50+$5=$60 + ~$0.25/kilowatt hour.
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The propane heater cost $80 and the 20# tank cost $43 = $123+$12=$135
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Although I will probably also purchase the $42 refill kit which comes with the one pount reusable propane tank for in-house convenience. refill kit so that I can fill the 1 pounder from the 20 pounder tank.
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One issue is carbon monoxide but the unit says it's safe for indoor use. But how do I figure out which is better in terms of cost efficiency?
BTW, this is my first fill ever of a propane tank where they charged me $4/gallon and they put in 4.4 gallons but why does the tank say this?
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"Save time and money. Did you know. New propane tanks need to be purged (air evacuated) when filled? This tank is pre-purged." If you bought a tank that was NOT purged, how would they purge it?
What information do I need to determine which is more cost efficient (when used to heat up a typical bedroom in a California winter)?
Propane is ~/gallon. Electricity is ~1. Propane is ~$4/gallon. Electricity is ~$0.25/kWh.25/kWh
"Approximate 2.4 hour run time on high and 5.4 hour on low with 1 lb cylinder"
I definitely don't have Bay area temperatures. I have a Big Buddy as a backup with the 20# tank. It takes a 1# canister but that would be useless to me. Another consideration is the propane heater is either on high or low. There is no temperature control.
While I have a forced air gas furnace it is noisy so unless it's very cold i use 2 1500W electric heaters.
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I saw the Vornado at costco and wasn't impressed. I've had very good luck with the Lasko brand.
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For a few bucks more you get something where you can set the temperature anywhere from 65 to 85 degrees and it will cycle on and off to maintain the set point. Most have a timer function and rotate. I don't use the rotate feature often but it could be handy.
Sorry I didn't answer your question about cost but for convenience it's electric hands down.
Thank you for that information about the 5.4 hours being on the low setting because the box only says 5.4 hours per pound and not what setting it's at.
How the heck do they run these things indoors without carbon monoxide gas?
It's GREAT that you have experience with the Big Buddy. Can I ask how well it heats up a room? Do you need to set it on high or can you leave it low?
It was on sale but I've seen the Lasko at Costco on sale in the past too.
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It's good to know that a key difference is the propane heater is like a fire in that it's all or nothing while the electric heater is controlled.
It's a LOT cheaper in initial costs (about $50 versus about $150 to $200). But I wonder what the respective costs are to run them to heat a room?
How long would it take the Big Buddy to heat a typical bedroom anyway?
On 10/11/2023 8:55 PM, Patrick wrote: > Is there an equation to compare heating costs of propane versus > electricity? > Being an empty nester, I have a house that used to have four kids and two > parents down to only the two parents, so I'm wondering if it's efficient > to just heat the bedroom and letting the rest go cold (SF Bay Area temps). >
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Both will heat a room but one is 1500 Watts max at about 25 cents per > killowatt hour while the other is 9000 BTU max at ~$4 per gallon propane. >
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There are some web sites that will help you. No matter the source, you will need X Btu to heat the room. Next, compare the cost to make a given amount of Btu.
Initial hardware costs were a bit more for the propane than electric.
Ignore initial cost for now. If the unit lasts 5 to 10 years, it is minimal.
> BTW, this is my first fill ever of a propane tank where they charged me > $4/gallon and they put in 4.4 gallons but why does the tank say this? >
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> "Save time and money. Did you know. New propane tanks need to be purged > (air evacuated) when filled? This tank is pre-purged." > If you bought a tank that was NOT purged, how would they purge it?
There is a vent valve.. They open the vent and pump propane into the tank and let it vent to the air and be wasted. You pay for that waste, of course. >
What information do I need to determine which is more cost efficient > (when used to heat up a typical bedroom in a California winter)? >
> 1. Propane is ~$4/gallon. Electricity is ~$0.25/kWh
Propane produces 91,452 Btu/gallon
1 kW of electric makes about 3400 Btu.
roughly 26.9 kW = 1 gallon of propane.
Or. $6.50 of electric to make the $4 propane.
> Is there an equation that allows me to compare heating costs?
Use the above numbers and figure how much heat you will need. That is the tough part but there are some on line calculators.
Factor in a few other things. Convenience. You have to cart around tanks, fill them, handle them. If you close off the unused rooms and continued with the existing central heat, how would the savings be? Worth the effort?
I was kicked out of arithmetic class in the 3rd grade. They never let me back in so I can't help you with sifering, but I can say that I close the heated air vent and shut the door to one bedroom when it gets cold, and I put a towel under the door, and I'm dang sure it saves me some money. I use the other 2 brs and the indoor privy, and there are no doors to the other rooms, but I've done what I can.
Good point, I'm not sure. I'd not be worried about a couple of hours of temporary heat but certainly don't want one in a sealed room, especially if I'm going to sleep.
Thanks for that starter information where what I did was use your numbers to check myself, and then I ran the numbers as shown below, which concluded that they both cost almost exactly the same per hour - but the propane heater puts out more heat per hour.
The rest of what I wrote below is how I came to that conclusion where I accept ahead of time that I could have made a math error (which is why I tried to check my numbers against your numbers as a double check).
Since propane comes in 1-pound & 20-pound sizes, I'll do that math. And since the electric heater is 750 Watt and 1500 Watt, I'll use that. Likewise, the propane heater is 4000BTU and 9000BTU so I'll use that. Lastly I pay about $4/gallon for propane & $0.25/kWH so I'll use that.
And a 20-pound propane tank (19.74 pounds, actually) is about 4.7 gallons of propane (where I received 4.4 gallons today but an exchange is usually only filled to about 3.5 gallons). Since 1 gallon of propane is ~4.11 lb at
77 degrees F, then a 1 pound propane canister is just under 32 ounces, or a quart (although I'll be loose with the sig figs).
One gallon of propane is 91,452 BTU so a one-pound canister is 0.243309 times that which is 22,251 BTU. A 20-pound tank filled with 4.4 gallons of propane would be 402,389 BTU (I'm cutting and pasting so don't worry about sig figs for now).
1 watt = 3.412141633 BTU/hour from your numbers (thanks!)
So that 1-pound propane canister containing 22,251 BTU is ~6.5 kWh. The 20-pound propane tank of 402,389 BTU is ~118 kWh.
At $0.25 per kWh, the 1-pound cylinder is ~$1.63 worth of electricity. The 20-pound propane tank is ~$29.50 worth of PG&E electricity.
My 20-pound tank cost about $20 to fill today, so that's about a dollar per pound of propane (using easy numbers).
The ads for the propane heater show how long it runs on a tank.
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"2.4 hour run time on high and 5.4 hour on low with 1 lb cylinder"
Now comes the problem of how long it takes to heat a room, given one heater is 750W/1500W and the other heater is 4000BTU/9000BTU.
Back to the conversion factor of 1 watt = 3.412141633 BTU/hour...
750 Watts is 2,559 BTU/hour; 1500 Watts is 5,118 BTU/hour.
4000 BTU is 1,172 Watts; 9000 BTU is 2,638 Watts.
Comparing wattage, they're kind of similar in heat output, with the propane heater being about 1-1/2 times hotter on low & 1-3/4 times hotter on high which doesn't seem all that much of a difference but clearly the propane heater is "hotter" per hour than the electric.
Using the runtime figures of 2.4 hours on high per pound, that's about 0.42 pounds of propane per hour. For runtimes of 5.4 hours on low, that's 0.18 pounds per hour.
Since the 20-pound tank cost about $20 to fill today, that's a dollar a pound, which means it would cost $0.42/hour on high and about $0.18/hour to run the propane heater on low.
Meanwhile, the electric heater at 25 cents per kWh is about $0.38 per hour on high and about $0.19/hour on low.
Hmmmm... assuming no boo boos, they're almost exactly the same price per hour (although the propane heater outputs from about 1-1/2 more heat per hour to about 1-3/4 more heat per hour).
Interesting conclusion... if it's correct.
Both cost about the same per hour but the propane puts out a bit more heat.
I don't know the terminology of a "space heater" as that's the same thing (to me) as heating a room - and whether or not it's vented is an issue but every room is vented by the very nature of rooms with open doors and heating systems that are vented and fireplaces that are chocked open, etc.
However, if you look at the photos, there's absolutely no doubt the heater is *intended* to be used indoors. It says so right on the box. Everywhere.
Look at the photo and let me know if this is a "space heater" or a "room heater" because I do not know the difference.
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Does that look like a "space heater" or a "room heater" to you?
Don't get hung up on the cost per hour. If one has to run for two hours at $1 per hour it is cheaper than a heater that runs one hour at $3 per hour. Btu is what matters. How long does it make to make say, 30,000 Btu and what is the cost of it.
I'm acutely aware carbon monoxide is a silent killer.
I was talking to a friend about this and he said the propane heater probably uses a catalyst since the packaging clearly states it's designed for indoor use, and there's no mention on the box about carbon monoxide.
Still, it seems prudent to have a carbon monoxide sensor in the room.
Even so, the quest is for the math right now where I think I found a simpler way to assess it given my friend told me it takes him about one to two hours to heat up his room nice and toasty in the winter with his 1,500 Watt Lasko electric heater (he said he has the fat one and the thin one where he says they both do the same thing only the fat one twists and turns and the louvers dance for you but he said none of that matters as all he does is leave it in the static position for both).
From before... Electric 1500 Watts is 5,118 BTU/hour; 750 Watts is 2,559 BTU/hour. Propane 9000 BTU is 2,638 Watts; 4000 BTU is 1,172 Watts.
So if he's running 1,500 Watts for an hour or two to heat a room from cold to toasty, that is about 5,000 to 10,000 BTU if my head math is right.
Using Ed's question, how long does it take to add 10,000 BTU of heat to a room?
Propane Heater: high = 1.11 hours, low = 2.5 hours Electric Heater: high = 1.95 hours, low = 3.9 hours
The propane is about 1-1/2 to 1-3/4 faster to get to 10,000 BTU.
It's also one room in the SF bay area which is a moderate climate, not ND. I looked at Patrick's analysis, didn't check it completely, but at first glance it looks and feels right. The advantage he pointed out, that the BTU output of the propane unit is higher, so it can heat the room faster is the main advantage. The disadvantage, I'd much prefer electric for safety and no combustion byproducts. Odd that no one has commented on the fact that the libs want to ban natural gas for cooking, but gas space heaters are widely used. Which exposes people to more combustion products? A stove that's used for a couple of hours or a space heater in a closed room?
"libs" as a perjorative is counter-productive and juvenile.
Elected officials in certain localities understand that natural gas is a fundamentally limited commodity, whose scarcity will only increase over the next decades. So those officials have chosen to support alternative energy sources in _future_ construction. They haven't banned existing uses of natural gas. Those officials are forward-looking and forward-thinking.
You'll need to support your "widely used" characterization of non-vented natural gas and/or propane space heaters. In my experience they're primarily used in construction sites with good ventilation, not in homes.
What's pejorative about it? It's just short for liberals. Are you ashamed of what you are?
So then they were lying a few months ago when they claimed the issue was unsafe pollutants from stoves that were hazardous to human health when inhaled inside the house?
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The Hearth Sense ventless blue flame gas wall space heater operates on Natural Gas OR Liquid Propane Gas and gives you 30,000 Maximum BTU of reliable supplemental heat that can heat up to 1,000 sq. ft of living space. Blue flame vent-free gas space heaters are clean burning, fuel efficient and safe to use. This gas heater works much like a central heating system in that it heats the air in the room by circulating warm comfortable air throughout the room. This blue flame cabinet heater is equipped with a thermostat which allows you to maintain and control the desired room temperature.
But then you should have known that, the OP found one and is considering using it. Do you think they found it in some back alley illegal market?
The catalytic process doesn't produce CO at dangerous levels. It does consume oxygen so it can't be used in a perfectly sealed area but few houses qualify. They do shut down if the O2 is depleted too much.
It will keep about 240 sq ft that is not very well insulated to 65 - 70 degrees with a outside temperature of 32. The high/low is the problem. There are two catalytic panels, one of which is used for low, both for high. When it gets too warm, throttling it down to low is necessary. Then the area starts to cool. Basically you become the thermostat with a lot of hysteresis.
The Big Buddy does have a fan option powered by D cells. I have not used it but for a longer term I'd hack it to use an external power supply or a car battery if a power outage was the problem.
I've also used it in my shed/shop which is about 100 sq ft and complutely uninsulated with ambient temps below 32. High will drive you out in short order with the same bang-bang control problem.
The current Big Buddy advertises 4000/9000/18000 BTU but mine is only
9000/18000. For the typical Bay temperatures 9000 will definitely heat a room unless you live in a drafty castle.
The price of kerosene has effectively banned them. They're even worse than the Mr. Heater propane type being discussed since they don't really work well except full on.
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