Looking for cheap heat supplement

[Derek]

We have a 5,500 sq ft building that I keep at about 60 degrees thru the winter.  My office is about is 15'x8' (120 sq ft).  60 is too cold for the office, but I dont want to heat the entire building.  I have an electric space heater, which does alright, but I'm afraid they use a ton of power though.  Anything solar powered would be ok, except the fact that its now been cloudy for 10 days straight here.  =(

So would I be better just running an electric space heater, something else, or possibly a 12v DC water heater?  Water holds heat better than air, but what would be more effecient in terms of power use?

[ghurd]

Watts and BTUs are convertable one to the other. X watts into water or air is Y BTUs either way. 1 kilowatt hour = 3,412.1414799 BTUs.

Does the office have hot and cold ducts, a normal ceiling, and the main area have a high ceiling? Insulating the office from the main area should help a lot.

But if it is 61' outside and in the main area, the heat won't kick on anyway, so a space heater is probably needed then.

There wouldn't be much control of the office temperature, but it's cheap!

The main area at 60' is losing heat to the 30' outside at a certain rate.

The 70' office is losing heat to the 60' area at a slower rate.

Its just bottling up the heat that is already there.

Saw it done before.

G-

[GaryGary]

Hi,

I agree with the note above that insulating the office from the main space should help quite a bit.

Solar heating can be a good supplement to your heating, and can be cost effective and reduce greenhouse gases at the same time.  Some ideas here:

www.BuildItsolar.com

Take a look at the Projects->Solar Space Heating area.

This is what I use on my workshop/barn:

http://www.builditsolar.com/Projects/SpaceHeating/solar_barn_project.htm

It only cost $350 to build, and saves about that much in propane each year at the current propane prices.

But, as you say, you will have stretches of cloudy weather, and you need some other form of heat for these.

[Laylow]

With electric heat you are not going to see much difference in efficiency.  The conversion from electricity to heat is very efficient; how much it costs depends on where you are getting it from.  Using fuel to make electricty to send to your office so it can be turned to heat is not very efficient.

Do you have solar panels?  If you already have another source for electricity other than the mains then you could use that with an electric space heater.

Your other option is some type of fuel heater.  Kerosene or propane probably.  If you have natural gas than use that.  The problem with the unvented units is the possibility of having unpleasant and in some cases dangerous fumes.  If your office is in a wharehouse type building this wouldn't be as much of a concern.  I would prefer installing a vented unit.

If you stick with an electric space heater, I would go with an oil filled radiator type that lets you choose between 600, 900, and 1500 watts.  Get a timer to turn it on a couple hours before you arrive in the morning and take some time to figure out where to set the thermostat.  The efficiency of the conversion from electricity to heat is the same as any other unit but it will still be cheaper to run.  The radiant heat will transfer to objects in the room instead of just sending hot air up to the ceiling.  The thermal mass of the oil allows the heater to stay off for longer periods of time.  With a 60° building, you can probably run the heater at 600 watts.  When you hook up your excersize bike generator you will produce so much heat that you won't even need to turn on the heater.

[Derek]

Excercise bike generator???  Sorry man, dont have one of those, haha.  Well, like I said with the solar, 10 days of no sun wouldnt work the.  I suppose a propane heater or just a small space heater would be the best then?  Neither are free.... but oh well, maybe just cheaper.

It would take a huge and expensive solar panel to produce enough power for an electric space heater wouldnt it???  I'd assume I'd want to hook this to a battery that would store lots of power too.  What would I need to do that then anyway?  Thats if I did go that route.  Thats probably going to be a lot more $$$$ though isnt it.

[Laylow]

Using solar electric to run a heater isn't a good idea unless you just have excess electricity that you need to dump.  Yes, you would need a big expensive solar panel and a bunch of other stuff.  I had a real brain fart and completely forgot about using the sun to heat directly.  If you are interested in a DIY project that can save you some money than this would be the way to go.  Someone posted a good link earlier on passive solar heating although you might also be interested in an active solar system.  You really need to search the internet and look at all of the possible designs out there.  The best one for you is probably going to depend on what resources you already have available and no one can figure that out for you.

An example of a simple active solar collector is a pump circulating water through some black hose on your roof and back into your office.  A passive system would attempt to do the same thing without a pump.

Search the internet, come up with a plan, and come back.  The forums work better when you've done as much research as you could and you still have unanswered questions.  Where you are starting from, there are just too many possibilities.

[Derek]

I've researched quite a bit on the issue, but not found a lot that would be extremely helpful other than this website.  )  Would heating water, which would then heat the small room be a working idea though?  I know for heating water directly its fine.  But transfering the heat from the water to the air is the part I'm unsure of.  But again, that relies on direct sunlight, which we havent seem to have had much of lately!  (  Its cloudy still, geez.  But wind is one thing we do have, thats for sure.  

[Laylow]

Here are some search terms that you can use.  Try them alone or in combination:

passive active solar collector "build your own" "heat exchanger" "make your own" hydronic "hot water" heater "water heater"

Yes, heating water to heat a room works.  I have no idea if that is what you should do.

Heat is transfered with a heat exchanger.  A car radiator is a heat exchanger.

[nanotech]

Have you considered a corn burner stove?

Honest question here.  There's a HUGE hardware store here that's also a farm power and equipment store all in one.  I'm talking this building is EASILY the size of a Super Wall-Mart!!  And they heat this sheet metal, uninsulated, 4 almost constantly open doors building with a corn burner stove.  In northern Minnesota.  Where -40 temps are not unusual.  And thiers is the demo model for what they seel for $1,900.....

When tax return time comes around, that's what's going in my living room.  My baseboards are eating me alive on the electric bill.  So they'll become lawn art by February!!

[nothing to lose]

"My baseboards are eating me alive on the electric bill.  So they'll become lawn art by February!!"

Save them for a dump load

 Corn and pellets stoves are good. If he can vent them from the office it might be a best choice, far cheaper than electric heaters and cleaner than wood. Less ashes to clean also. No bugs.

I think some I have seen run on a thermostate even, feeding just enough pellets to keep the fire lit when the room is warm enough and when the room get cold feeds in more pellets for heat. Maybe they all do that, but I think I saw some you manually adjust the flow also, not sure about that.

As for Solar Heating, I would not give up on that if you can use it. Sometimes there is a good deal of heat even on a cloudy day. Solar pannels might not be producing much power, but the cars still get hot inside. Was  cloudy cool days for a bit here, cars nice and warm anyway. Warmer than my house even, I had let the fire die out because I was leaving for awhile in the afternoons. Closed room on the sun side of house was warmer than rest of house also, solar gain even with clouds.

 A good home built solar heating system would have been working ok, not as much heat as on a sunny day, but still some warmth. On those days you do have good sun then you may not need other office heat. I probably would not want it as the only option but could be good as a secondary system.

[Kwazai]

http://www.ruralenergyproducts.com/Alternative_fuels.aspx

cost comparison- I'm assuming the corn price is based on a winters worth or better(truckload...)

[Kwazai]

this may sound silly, but this ran thru my mind yesterday and a few years back I had read thru a government study on burning btu values of just about every crop I could think of which made me think it may be viable.

take yard waste(leaves, grass clippings etc.) and use a trash compactor to make a sortof cigar out of it to be burned in a tin can stove(gasifier type). the compacted waste would be like burning a  cigar from one end to the other. with a forced induction system and temp controller.... not real sure about the specifics on how the gasifier would look. I also wonder about a pellet stove being setup like a gasifier stove.

http://www.repp.org/discussiongroups/resources/stoves/index.htm#news

[Laylow]

His delta T from the building to the office space is only 15°.  If I had $2000 I would buy a corn stove and use it at my house.  A corn stove can burn pellets but a pellet stove can not burn corn.  Corn burns at a higher temperature so the stove has to be built to withstand the heat.

How much money do you want to spend?

Where is the building heat source in relation to your office?  If ghurd's solution is possible then it is THE correct answer.  It might just be a matter of closing all of the heating grates outside of the office and locating the thermostat in the office.  Set it to whatever you want and forget about the temperature in the rest of the building.

[Derek]

Well, point was to heat only the office.  Its not next to a window though either, but the next room back, about 25 feet from it.  Hey with the hydrogen fuel cells, basically it seperates hydrogen from oxygen in the water.  Wouldn't it be possible to just burn this hydrogen just like a furnace using natural gas?

[nothing to lose]

I did not look at the link for corn prices, here for me it would be $6 per hundred pounds bagged, maybe less if I took a truck load in bulk?

 Yes, I kinda wonder why people rake up leaves then burn them in that nasty smokey pile by the side of the road, then BUY fire wood and kindling.

 I been looking at my woods, been letting leaves sit and composte or mulch, but now I see I seem to be loosing my privacy because of it. Where I once could barely see through the brush even in winter I can now see the road clearly. I have not cleared it!

 So I figure it's time to remove the layer of leaves that must be killing out the berry vines and other brush, let the sun get to the dirt and start some new growth here.

Now what to do with acres of leaves?? Thinking of several things for a leave burning stove. Told the wife I was gonna cut the firewood expense and no electric heat and burn leaves.

 She said, "What, you think leaves grow on trees"?

Oh well, lots of heat in those there leaves, good as firewood really. Burns fast, hot, clean, if dried properly in the sun. So my leaf burner stove will probably be an outdoor water heating system. Let leaves burn fast and clean and store heat in water or veggie oil to pump into house.

[Laylow]

I don't know where you are getting your hydrogen from but if you are making it yourself, you'll spend more in electricity to get the hydrogen than you would to just make heat.  Try again.

[Derek]

Well, essentially, a few volts of electricity is getting hydrogen out of water.  This electricity is obtained with a solar panel, then stored in a battery.  Anything that ignites will supply heat obviously.  Maybe I dont understand hydrogen that well yet though.  But if thats possible, that would seem like a good way to go about this.  So I suppose I'd like to know how to get the most hydrogen out of water, how to burn it, that sort of thing.  Any ideas?

Otherwise, its leaning towards an electric heater again.  haha  There's gotta be some good way to do it though, with some sort of cheap or free energy sources.

[Derek]

Hey actually, I just found this:

http://www.heatnglo.com/products/fireplaces/aqueon/aqueonhome.asp

It says 31,000 BTU's on it.  Now granted, they are selling it for $49,900, but I highly doubt it would cost very much to make such a thing.  It uses 220 volts, 60 amps I think is what it said.  Very interesting idea though, would a homemade something like this actually work?

I wouldnt see why not.  You'd just have to know exactly how to arrange all the parts basically right?  

[Derek]

Now this seems a little off the wall, but does anybody know if the idea works or how it works?  It supposedly uses motor oil which reacts with a zinc rod, and makes heat, thats all....

http://www.fuellesspower.com/Heater2FREE.htm

Sound like something that might work or not?

[Laylow]

220. V x 60A = 13200W
     
13200. W = 45,040BTUs
       
       

It's a very expensive science project that can teach you a very expensive lesson.

For a cheaper project just drop two carbon rods in a bottle of water, hook them up to a 9V battery, and light the gas that comes out the top.  It's fun, but it doesn't have a practical application for heat.

[Laylow]

Sorry, for some reason that come out correctly.

220. Volts x 60 Amps = 13200 Watts
     
13200. Watts = 45040 BTUs
       
       

again, better off going straight to electric heating element.

[Laylow]

Moderator:  This keeps coming out wrong, I don't get it. Is it some weird formatting problem?

13200 W = 45040 BTUs

Doesn't like the number 13?

It comes out fine in preview but when it posts it turns to 200 watts and with a period.

I won't try again after this.

[TomW]

I think you simply need to turn "off" autoformatting down under the typing area set it to "plain text".

Otherwise it thinks you are posting a list

so:

1. 
   
2. 
   
3. 
   
   

Cheers.

TomW

[ghurd]

I have hundreds of galvanized oily bolts, but none of them are hot, or turned magnetic.

[TomW]

G-;

Nyuck Nyuck.

Yeah that site is a HOOT i doubt if there is one practical, workable device on the entire thing. Surprised they don't list a 500% efficiency MPPT for wind.

As P.T. Barnum said "There is a sucker born every minute". And the internet seems to capitalize on that fact.

Just my mean and nasty opinion. or as my buddy says "sending internet bullets". Whatever that means.

I just can't help myself I get so giddy when these sites get posted like they are the holy grail. No offense to anyone intended.

Cheers.

TomW

[Propwash]

If your office is on a cement slab it is like heating a room on a block of ice. I had a very similar set up in my last business. I was always cold while working in the office. I used a hot air furnace to heat the place. I kept choking off the ducts going to the main work area to force more hot air into the office ducts. This was fine during the day but during the evenings when doing endless amounts of red tape and paperwork I would have to heat the workarea as well as the office even though the work area was not being used. I ended up installing a small mobile home furnace in the office area. They work quite well and some of them can just be ducted out the bottom onto your slab to keep it warm and radiant heat the office by keeping the slab warm. Most of the guys around here are installing radiant heat in the cement slabs when building a garage with several zones so that the temps can be controlled in office areas independently from work areas. They are using an oil fired boiler or propane water heaters to heat the water. I am trying to find cheap heat to use in my home during evenings this winter. I am building a twelve foot mill and plan on using all of the power from it to create heat. Even though it may not be practical use of wind mill power I can't see that it will be costing me anything and I will consider whatever heat I produce cheap heat. I would think this would be a possibility in your situation as well but I have no facts yet to prove my theory.

                      Kevin

[Kwazai]

looks like a battery of sorts- galvanic corrosion of aluminum and zinc with the steel- to produce heat. I wouldn't think there would be very many btu in a tin can size unit-possibly something the size of a telephone pole transformer to heat a room??

http://www.howtobrew.com/appendices/appendixB-2.html

(simplified info)

putting sodium hydroxide into it would probably make it a prolific hydrogen producer (catalytic reaction), but would also consume the aluminum and zinc.

L8r

Mike

[Derek]

This "zinc rod in a can of oil" seems like an interesting idea though that could maybe be improved upon.  Although as always, I think if anyone had a great breakthrough idea that would improve the world, it shouldn't be sold, but thats just greed for you.  

Obviously there is a reaction of some sorts happening there though.  I would have to say that the zinc is being eaten away then most likely.  But havent to replace that every once in a while wouldnt seem too terribly expensive comparied to other types of heat.  Surely if it works on a small scale with a bean can, you could build a large type that put out more heat.

I've learned one thing though, surface area counts for a lot.  Many smaller rods with zinc would be better than 1 large one.  Anybody else heard of such a thing?  I guess what we'd look for would be how zinc reacts with motor oil.  But I cant imagine that it does it on its own.  I'd think it would take some current applied surely wouldnt it?

Very interesting idea though if we could re-create such a thing!  Paying $40 for a possible scam idea though, nah, dont have that much to waste on such a thing.  Now $40 in material for some trial and error, yeah maybe.  Anybody know anything about this idea though?

[richhagen]

Don't waste your time or money on that.  Rich Hagen

[hiker]

try a vent free propane heater--they cost about 150 bucks for a decent one..

dont know if you have a place for a small propane tank..

used one in my motorhome--worked great -i just kept one of the front windows cracked open a hair...or you could use the  smaller heaters that use the small bottles that screw in ..real hassle thou--plus they cost way to much.............

[Derek]

I've found a bit more info on such a project now.

http://www.miniscience.com/projects/airbattery/

http://www.creative-science.org.uk/sea1.html

http://www.ieee-virtual-museum.org/collection/tech.php?taid=&id=2345793&lid=1

Surely if we can get electricity from fruit, saltwater, or something else, then generating heat with such a system must be possible too.  Of course it wont last forever, I know this.  But buying zinc bolts might be fairly cheap as opposed to other methods.

What do you think of the above links?

[whatsnext]

How big is that corn stove? Corn, burned at 80% eff, produces 6400 btu/lb. Period. It is not an over unity fuel. The building you describe could easily use 1,000,000btu/hr. Is the stove burning 150lb/hr? I like corn as much as the next guy but it does not burn that cleanly as there are always clinkers to pull out of the combustion chamber and it is somewhat difficult to store because it is a food that animals want to eat if given the chance. I have yet to see a corn stove that produces more than 100,000btu/hour but nanotech has found one for sale that produces ten times that. More likely the $1900 that he has to spend will buy him a 50,000btu/hr stove that, while nice, wouldn't raise the temp of a Wal-Mart more than a couple of degrees. This is the problem with this board.

John...

[TomW]

John;

This is the problem with this board.

Whats that, john, self proclaimed know it alls like perhaps the person making that observation about the board? Not that I feel you qualify just holding up a mirror.

Just curious what you mean here. If that is what you mean I guess anyone with any sense at all should know that anyone can play "expert" online with absolutely no requirement of any real knowledge of a subject.

Just calling it as I see it. Personally I don't know a BTU from a CPU I just know it takes a big pile of firewood to heat a large space. Usually it comes down to weight once dried. Of course I am no expert on wood heat I have only heated with wood about 40 years or so.

T