I need an electric space heater...

[ddrueding]

I need an electric space heater. Does anyone have a favorite? Room is stand-alone workshop about 10'x10' with no insulation. Outside temp could get down to 35F. I'd like to be able to keep the inside as high as 75F. Should I just look at somesimple insulation and a killer lighting system? Whatabout the oil radiator-style ones vs the electric filament ones?

Raining heavily outside right now, 60F...

 

[sechs]

I like to use Pentium 4s, but they're kind of expensive.

Usually, I just put on some extra clothing and/or blankets. I haven't used either heating or cooling since moving from Pennsylvania, and foresee any real need to so do. It used to get down into the forties *inside* during the depths of winter, *with the heat on.* I have yet to meet anybody near here that has experienced that here.

 

[ddrueding]

I'm at my GFs house and it has the remarkable capability of maintaing a temp LOWER than ambient when the heater isn't on. I need to figure out which wierd dimension it's using and harness it's power. Right now it's 60F outside and 56F inside. The heater was on earlier, so after turning off the heater the interior temp settled lower than ambient....wierd.


But the reason for this heater is because she's a jeweler. As such she can't wear anything on her hands while shes working, she sit's still for extended periods, and there's occasionally open flame. I'd feel more comfortable if she didn't have loose clothing hanging around.

 

[sechs]

If it's colder inside than outside... open the windows. Obviously, that's not as helpful in today's weather.

In reality, the house needs a check on its insulation. If she works from home and *needs* environmental control, she needs to invest in an actual system. A space heater isn't a solution to that problem; simply a new problem.

 

[ddrueding]

Her curent workshop is a 10'x10' freestanding shed built in 1935 that sit's in her garden. We can ignore the house and freestanding garage for now. The shed is 100sqft and has no insullation, one singlepane window and one door that doesn't close correctly. She is hesitant to put any money into the shed as she plans to abandon it as a workspace this summer. She is instead interested in getting an electric space heater to keep it warm during the (rare) cold days. I'm more inclined to add some insulation as well, but considering how crowded the space is, this would be a considerable amount of work. On top of all this, the space heater I just lent her keeps blowing out the circut, so something low-powered is likely a good idea. I was considering kerosene, but with the acetolene and oxygen tanks sitting around, it make me nervous.

 

[sechs]

There's not enough service to run something electric. Anything else is going to use a fuel and pose fire, asphyxiation, and/or gas poisoning hazard. You don't really want those in a shed. And if the building is going to be abandoned relatively soon, then there's no point in making much investment into it, anyway.

I'd suggest avoiding using the building when it's too cold or, alternatively, sucking it up. When you choose to use a space that's not fit for your purpose, then compromises are made; this is one.

 

[ddrueding]

Option #3 (currently employed) Extension cord from house to electric heater sitting in shed. Still looking for any efficiency info on electric space heaters.

 

[LunarMist]

I like to use Pentium 4s, but they're kind of expensive.

:mrgrn:

 

[Santilli]

Check with Costco for a low cost solution They sell HeatDish electric heaters that seem to work great. I use one in my room, and my house is likewise a bit on the cool side.

Gs

 

[Bozo]

I use a small electric 'ceramic' heater when my P4s are shut down.

The heater draws 13 Amps. You are going to need a pretty hefty extension cord to power any type of electric heater. Minimum should be 14 gauge wire. If you are going to be over 50' from the house, you might need 12 gauge wire or the extension cord could become a heater and really cause problems.

Some camping outfits have self contained gas heaters that use small bottles of gas. (Benz-o-matic type) These are usually pretty safe when used correctly and can be used indoors. Maybe leave the window open a crack.

Bozo :mrgrn:

 

[sechs]

Option #3 (currently employed) Extension cord from house to electric heater sitting in shed.

Danger Will Robinson. Fire danger ahead....

 

[time]

Combustion heaters chew up your oxygen, and to a greater or lesser extent replace some of it with Carbon Monoxide. Ergo, they can kill you in an enclosed space (although a shed is hardly likely to be airtight).

Here's a plan for keeping warm:

1. Seal everything, especially the ill-fitting door. Most heat loss is through air leaks. Unless you're incredibly overzealous, a shed will still allow air changes after you've stopped up everything in sight.

2. Insulate the ceiling. Warm air inevitably rises, and a bare metal roof is an excellent heat conductor. Even an ordinary ceiling helps, although it needs to be fairly airtight.

3. Cover the window, ideally at the top as well. Glass is a lousy insulator and the resulting convection (visualize a waterfall of air down the glass) will chill your room in no time. Come to think of it, if the walls are steel, you'll be up against it unless you can cover them with drapes or something.

4. Radiant heaters offer more comfort than convection heaters (eg oil-filled), particularly if the place is drafty. Multiple lower power units may be better than a single high power unit (more even coverage). If you're feeling adventurous, I'm not sure there's anything to stop you wiring a two-bar heater in series rather than parallel (if they're of equal resistance and note that I've never tried it). A low position is obviously the way to go.

 

[Bozo]

The efficiency of an electric space heater is almost 100%. For every watt of electric used, you get 1 watt of heat...minus a small amount for the fan if so equiped.
But, electric is usually the most expensive for of energy.

Bozo :mrgrn:

 

[timwhit]

But, electric is usually the most expensive for of energy.

This might have changed recently with natural gas prices up ~40% this season.

I'm trying to figure this out.

I pay 8.275 cents for the first 400 kilowatt-hours of electricity and after that I pay 3.734 cents per kilowatt-hour.

1 Therm costs ~$1.55 and contains 105,480,400 joules or 105,480.4 mega joules that equals .0000172 cents per mega joule (this includes efficiency of 85%, new natural gas furnaces run at around 85% efficiency.)

1 kilowatt-hour contains 3,600,000 joules or 3,600 mega joules that equals .0000229 cents per mega joule after the first 400 kilowatt-hours the price drops to .0000103 cents per mega joule

Electric heaters run at 100% efficiency, not including any kind of fan. But, gas furnaces also have a fan so we will not consider the fan at all.

So, it appears that gas is cheaper if you are only going to use up to 400 kilowatt-hours of electricity (33% cheaper), but if you are going to use more then electric is about 59% cheaper.

Note: There could be errors in my math. Anyone feel like checking it through?

 

[timwhit]

I made a couple errors in the above post. The numbers should be 3,600 kilo joules and .0000172 cents per kilo joule instead of mega joules. Same for the electric conversion that I did.

Either way the math behind it is correct.

For a normal sized home (say 2500 sq ft), in a northern climate (like Chicago), electric would most likely be cheaper.

 

[ddrueding]

Very interesting math timwhit, I wonder what that means in a broader sense.

 

[sechs]

The efficiency of an electric space heater is almost 100%.

Keep in mind that your average incandescent lightbulb is 95% efficient as a heater. You can slot some 100W lightbulbs in there and get the light *and* heat.

That doesn't fix the hazard caused by an extension cord running from the house....

 

[Bozo]

Come to think of it, I use a 300 watt quartz light to work on my car and warm up the garage.
A 300 watt quartz light should be great for jewlery work

Bozo :mrgrn:

 

[Bozo]

http://www.lowes.com/lowes/lkn?action=productDetail&productId=74012-290-WQ300&lpage=none

Bozo :mrgrn:

 

[ddrueding]

nice idea bozo...

 

[Explorer]

> I need an electric space heater...


Easy. Make a space heater out of a few dozen old 1.4 GHz Willamette Pentium 4 processors. Simply increase the clockspeed towards 2.0 GHz to dramatically increase room heat.

 

[sechs]

You're a little behind the second post, but we love you anyway.

 

[Tannin]

it has the remarkable capability of maintaing a temp LOWER than ambient when the heater isn't on. I need to figure out which wierd dimension it's using and harness it's power.

Send it over here! Send it over here!

 

[ddrueding]

Just a bit o' braggin'...

11PM December 22nd, 62F with light rain. I love our seasons here (rain in the winter and summer, fog in the fall, and sun in the spring)

 

[Tannin]

That's about ... er 15 or so isn't it? (I haven't used degrees F for 30 or 40 years now, and don't relly remember how they translate anymore. And I'mm too lazy to look it up or multiply it out.) Isn't that rather warm for the time of year in your location?

 

[sechs]

According to my handy thermo-rule:
68F = 20C
61F = 16C

So maybe 17C.

 

[Stereodude]

Don't those Halogen work lights say to not use them indoors?

 

[mubs]

62F = 16.66667C. Freeware called Convert is pretty good; I install it on all systems I set up.

It's been rather warm for this time of the year in S. CA as well; I'm sure Buck and the other denizens of this area will concur.

The last few years have been very atypical as far as weather and rain patterns go, in many parts of the voild.

 

[Pradeep]

Hi Tim,

Is that electricity pricing including supply charges etc? A high efficiency gas furnace can get you close to 95% efficiency. It wouldn't surprise me if electric was cheaper this year, after the insane increase in natural gas.

 

[timwhit]

I'm not at home right now so I can't check my bill. But, most of the bill is racked up with the 8 cent and 3 cent charge based on how many kilowatt-hours have been used.

The price of electricity is set by the state of IL (I don't know how other states do it). They basically have to OK any kind of price increase before ComEd (Exelon) can increase the price.

For reference the cheaper price of electricity (3.734 cents per kilowatt-hour) is only in effect for the winter months. So don't assume that when you are using your air conditioner in the summer that it will get cheaper after 400 kilowatt-hours have been used.