I am in a situation where I have to heat a small utility room (9 x 9) in my basement (two below grade concrete walls, two framed walls) to prevent it from freezing. The rest of the house, which is under construction, will be left cold for much of the winter. The room will be well insulated and has no windows. My cheap solution for this winter was to use portable electric space heater(s) to keep the room warm, but I am concerned b/c I will need to leave the room unattended for a week or two at a time. If something went wrong with the heater or the electricity powering it, I would be in bad shape. Any preferences for the safest and most reliable space heater? I was thinking the oil filled electric radiator(s)……
If this seems like a bad idea all around, what other suggestions do you have? My second choice, although much more complicated, expensive, and generally less desirrable, was to install an Orbis type propane wall furnace which would be direct vent but would not require electricity. The house will not have a central heating system until next summer, but I will have a permanent propane supply to the room within a few weeks.
What do you think?
Replies
As an electrician I often have a call for portable heaters. Electric strips go down, services or panels go phooof, a highly technical term used by all the better electricians, leaving homes limping along fed with emergency power only. Typically the main heat can't/won't work and, even in Florida, the temperatures can plummet.
In anticipation of this eventuality I keep a small collection of space heaters on hand. After much thought as to what would be safest I settled on small, 1500 watt maximum, ceramic units.
These have several advantages:
First they have a low of inherent and included safety features. Ceramic heaters run relatively cool. The heating element doesn't get hot enough to ignite toilet paper. Most, make sure to check these features are included, have both an over-temperature and tilt cutoff.
If it runs too hot, unlikely due to the low operating temperature but possible if the intake was blocked, or the unit gets tipped over, the heater will stop heating.
Also these units are cheap. About $16 at major discounters.
Being electric they are not subject to fuel leaks or oxygen depravation that can cause explosions or smother the occupants of the house.
I keep a couple of these units around my house to take the AM chill off or warm a single room in addition to another four for customers homes should they be needed. Two will keep a small home toasty or a medium sized home bearable. I used all four in a hanger-like McMansion and it was comfortable, for me, with a sweater on, this with temperature in the 20s, if not overly hot. About 62F I would guess.
Here is a related question-
Electric heaters of various types may draw 1500 watts, but what heat output do they produce? I am surprised that these heaters do not list btu output as well as electrical draw. I am assuming that the various types of electrical heaters do not all have the same efficiency, of course- although I may be wrong in this assumption.
As I understand it all electric heaters using resistant coils are equally efficient. proximately 100% minus any fan motor losses which should be minor. The designs vary by how they move the heat. My little ceramic units use a fan to move the heat while an oil filled radiator would use natural convection.
Standard conversion of Kwh to Btu is:
Kwh x 3413 = Btu.
1500w x 3413/1000 = 5119.5 Btu /hr.
Been a long time since I worked with this but is sounds about right.
You are right, every electric heater is 100% efficient, by definition. Any claims to the contrary are just sales bogus. Even if the heater has a fan, the energy the fan consumes is also converted to heat. Light bulbs are the same, a 60watt bulb produces 60watts of heat, hence 100% efficient.
Space heaters are all 100% efficient. This is hard for people to understand, but true. The differences are in quality, surface temp, size, air circulation, thermal mass, color, etc.
"Light bulbs are the same, a 60watt bulb produces 60watts of heat, hence 100% efficient."
Not exactly. It is USEFULL energy that measured for the output.
For light bulbs, in most cases, the desired output is light. So only light energy output is used in the calculations.
All electric resistance heaters have 100% efficiency. Even the power to the fan is eventually converted to heat.
Re the original question, probably two small cheapo electric space heaters (get ones with built-in thermostats), on two different circuits. If kept a foot or so away from any combustable surfaces they're almost totally safe. Having two units will give you some redundancy if one blows a fuse for some reason.
Just make sure that the units are not too large for the circuits they're on, and definitely don't put two on the same circuit.
Good point about putting them on different circuits.
Given my druthers, your making this call, I would get the ceramic units. I used to work in a machine shop and the guy next to me used to light his cigarettes on the red-hot coils on a classic milkhouse heater. I have seen red-coil heaters flash when the dust builds up or a large dust bunny gets in them.
Never saw one cause a fire but it would be, IMHO, possible. The oil filled units could be a good choice also. Better to be safe.
Yeah, the units that operate at a lower temperature are safer, but in this well-controlled environment it probably doesn't make much difference. I'd say pick the best tradeoff between cost and apparent quality, since you want reliable units. It probably wouldn't hurt to get two different brands/styles, just to avoid the possibility of a batch with bad thermostats or whatever.
Electric resistance heaters are considered 100% efficient...which sounds impressive, but from a $$ point of view, they tend to be some of the highest priced heat (unless nat. gas goes up another 300% this winter).
I'm going to try and attach a converter program to this posting. Don't know if it will take an exe, but I'll try. handy little half-meg program for converting various units. Shareware or freeware.
It includes a BTU to Watt conversion. Lets see, that healthy sized wood stove I was trying to talk my BIL into puts out up to 55k BTU, which with electric resistance heat would be 16,119 watts/hr (16kw/hr), which if running 24 hrs would be 384kw/day... or if running for a 30 day month, 11,520kw. And if the power company is charging $.07/kw, that would come out to a monthly heating bill of, $806.40. Wheeew! Think I can find wood cheaper than that ;)jt8
Electric is a very expensive fuel sorce...
but about the most efficient..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Thanks for the info. As I said, I only need it as a temporary fix for 1 small basement room. By next winter, I'll have a central heat source to complement my woodstove. But that is a subject for a different post..............
Also, some electric companies will give you a discount for an "all electric" house (heating, water heating, cooking, etc).
However, if I was heating my house with electricity, I would rather do it via a geothermal heat pump rather than electric resistance heaters.
jt8
Edited 10/11/2004 12:51 pm ET by JohnT8
Electricity is just about the most expensive way to go...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
I would assume safety and the ability to operate unattended, even though most manufacturers warn not to use their units unattended, would offset the cost.
A cost that could be considerable reduced if the units were set to come on at a low temperature, I assume something a reasonable touch above freezing, and the house was well insulated.
Adding storm windows, even the plastic heat-shrink ones, and further weatherizing the home would also help reduce costs.
Since Mike's question has been answered, I will sidetrack the thread.
IMO, sister and BIL's house is in need of some blown-in insulation and supplemental heat source. They have a fairly new boiler in their nearly 100 yo house (2.5 story 2600+ sq ft, 9' ceilings, orig windows + storms). But even with the mild winter we had last year, the boiler just couldn't keep up. When it was zero outside, it was like 50-55 F in their house! At which time the radiators were too hot to touch (and the boiler wasn't hardly shuuting off)... and the nat. gas bill was nearly $400 for one month.
That is what I call adding insult to injury. Sitting in a 55 degree house but still paying that much for nat. gas. The PO had used the two fireplaces (LR and MBR) to supplement the boiler. I suggested an efficient wood stove hooked to the LR fireplace. BIL had been planning on having a chimney sweep inspect and install SS ductwork in the fireplace chimney for the wood stove, but sister is afraid it will burn the house down.
So then method #2 for improving the indoor temp: insulation. We tried to talk them into getting insulation blown into the walls, but my sister was afraid the stuff would mold. And apparently we don't have anyone local who can blow Icynene (which doesn't mold)... but then she's worried about foam popping the plaster. My thought is, "if the foam guys pop your plaster, then they pay to fix it. They're professionals who should know how to blow it in w/o damaging the wall"
So now they're thinking about electric resistance heaters. 4-6 1500watt heaters kicking on and off all day. I can only imagine what the electric bill will be! From my point of view, all I can do is offer advice and then step away. It isn't my house. If they wanna pay those bills that is up to them.jt8
A decent wood stove with SS chimney liner is far less likely to burn down the house than a fireplace.
Too bad your sister has swallowed the stories about blown-in cel getting moldy. It (combined with decent floor insulation) would almost certainly solve their problems.
The electric heat thing is pretty much guaranteed to be a fiasco (and may also burn down the house). At most they should set up a "safe room" with mostly interior walls (and floor) and just heat that one place during cold spells.
A decent wood stove with SS chimney liner is far less likely to burn down the house than a fireplace.
She won't use the fireplace either, but I'm in agreement with you on the wood stove. There is a certain element of risk with burning anything, but with proper venting/setup and intelligent usage, the risk is minimal. I'd be tempted to WAG that it would be less risk than having 4-6 electric resistance heaters plugged into various places. And considering what their power bill is going to jump to, you could pay that wood stove off in a hurry. A friend puchased a stove from:
http://www.woodstove.com
About 3 or 4 years ago. He and his wife have enjoyed the heck out of it. They let people know during the year that they need firewood, and I don't think they've PAID for firewood for 2 or 3 years now.
His favorite saying about using wood for heat is that wood heats you THREE times!
Once when you cut it, once when you split it and once when you burn it.
Too bad your sister has swallowed the stories about blown-in cel getting moldy. It (combined with decent floor insulation) would almost certainly solve their problems.
I agree.
The electric heat thing is pretty much guaranteed to be a fiasco (and may also burn down the house). At most they should set up a "safe room" with mostly interior walls (and floor) and just heat that one place during cold spells.
I had even suggested that they bump up the attic renovation. It had been slatted for next Spring/summer (but I think its 1 or 2 years away really). They could create a well insulated area in the attic and then have a comfortable portion of the house (be it summer or winter).
The BIL doesn't take any work to convince, but my sister usually kills whatever plans emerge. OK fine, she's the one living in the 55 degree house, not me! :)jt8
I wouldn't recommend heating an entire house in the normal manner with small electric heaters. Even though this is essentially what the large resistance units do. It can get pricey unless you have very low electric rates.
I hear some locations near hydo-electric plants have such low rates that you would be nuts to have any other form of heat as anything but backup heat. I din't know if these low rates are still true given the tendency to sell power for profit.
Small space heaters to keep anything but a small cottage at something like 68F in sub 10F weather, barring some of the super insulated designs, would be prohibitively expensive. Assuming normal insulation levels, an average sized home and average electric prices these small heaters are good for either keeping small areas like an office at comfortable temperatures while allowing the rest of the house to ticking along at a more cost effective cooler temperature. Alternately they also will keep the much larger whole house just above freezing so the pipes don't burst.
As spot heating they excel if the use is both limited in area and time. A lot of other heating systems take time to get the heat to you. A small electric heater is nearly instantaneous.
I think your right. Insulation and more efficient heat sources are the way to go. If your in the frozen north where heat is literally life and death important you might take a clue from those who have two, sometimes more partial or complete systems using different fuels.
I know one ex-northerner, we still call him 'yank', who described his family home up north as having central oil heat and propane heat, wood stoves and electric space heaters. He had the oil and gas rigged to keep running off a tiny generator if the power goes down. He said he would go with an inverter and a couple of deep cycle batteries when he saw me using my inverter. After I flattened my battery he said he would keep the generator handy. Just in case.
Idea here was that he could use alternative fuels if prices went through the roof on one source or the supply got short through national shortage, price gouging or local disaster. Redundant systems can be complicated but they are flexible and adaptable.
We're all "singing to the choir" here. I know it isn't a good idea, and everyone posting here knows it isn't a good idea....but you can't convince them of that.
If two 4' wide radiators too hot to keep your hand on can't keep the room at temp, how do they expect a 2' wide electric resistance oil-radiator to do it?
Some times you need to stand back and let folks fall on their face. Its the only way they learn. I think the electric bill after the first cold month will do the trick.
jt8
I vote for the insulation, big time.
Doesn't matter how efficient the woodstove or furnace is if you can't keep the heat in.
I love a wood stove, though. Been around them most of my life. Might be a good idea to ahve your Sister visit a house with a wood stove on a cold day. That might be enough to change her mind.Bumpersticker: If you lived in your car, you would be home right now.
I'm with you, Boss. A good wood stove is hard to beat (especially if you've got a cleanout pan on it and don't have far to carry wood in or ash out). I've got a friend who put in a nice soapstone wood stove a few years back, and I've tried to use his setup as an example. Pictures aren't enough though, and he lives 7 hours away.
If you'll allow me a sexist comment.... women LOVE woodstoves. Women are like cats in their desire to be next to something warm, and wood stoves are great for that (give off a lot of heat and don't talk back). The friend's (who got the wood stove) wife didn't like the idea...until they'd had it for a couple weeks. Now she loves it and is just as likely to be keeping it stoked as he is (although he still 'gets' to split and carry the wood in).
If my current house could fit a wood stove in, I would do so if for no other reason than to show her how great they are, but isn't an option for me....
And insulation is a no brainer (or is for MOST of us!). <sigh> Hope they don't expect many visits from me after about mid November until about mid March.
jt8
Edited 10/12/2004 5:14 pm ET by JohnT8
"...women LOVE woodstoves..."
I'd have to agree with that one. Women are naturally cold-herted, and are attracted to the warmth. (-:
Actually, my Mom is better at tending the fire than Dad is. Don't know why that is, but it's definitely the case.Love is like the sun: when it's there, you just want to wallow in its glow, and when it's gone, you just want to sleep and drink hot chocolate.
Heres my story. End room on a large house with high ceiling, could not get it warm or cool when needed. added 12" of insulation to the ceiling, refinished with T&G unfinished wood planks (this was 9 years ago). Heating now warms up great and turns off (used to run non-stop) A/C cools the room almost to much. And its all down to heat loss and gain control. Get your sister to insulate and get instant payback for the work done!!
The oiled-filled ones are inherently safe. No part of them gets near hot enough to support a flame.