Greenhouse heat - kerosene

I have a cool greenhouse. That means heated to minimum 38 degrees F in winter. Just enough to save over my tender perennials. Question: We use a portable kerosene heater. One of my fuchsia friends asked me if we had trouble with this sort of heat? Seems that propane is more popular. Are the fumes from kerosene heat a problem?

My DH says that if you have a really clean burn the only by-products are water and carbon dioxide; however, he also says there is no such thing as a clean burn, and therefore you will also have unburned hydrocarbons and carbon(soot). This can settle out on plant foliage, and should be rinsed off occasionally.
Propane is cheaper and burns cleaner, so it is the fuel of choice. Both types of heat can create carbon monixide which is poisonous to people, and should be vented to the outside.

I agree with sky. Propane is much cleaner to heat with and in my opinion less dangerous to use. Check this out.http://davesgarden.com/t/142706/kerosene+heater

We heat with propane also, but in my first ghouse I used a kero heater as a back up (was mainly heating with wood in that ghouse).
The kero did just fine and I didn't notice any problems with growth or soot. (I'm sure you know tho that it sure does stink when you are running out of fuel, and even turning it off...that's when I'd smell the fumes.)

I put a small propane heater in my "shoffice" last yr (to back up my wood stove) and love it. They can be purchased for as little as $150 at Lowes or Home Depot, can be wall-mounted or left on the floor, and will run off small tanks of propane. They burn really clean (so clean they don't need venting), have built-in thermostats, and don't require electricity to operate. I think that would be a great heat source for a small greenhouse.

Shoe, I think it was you that told me last year of a company that sold the propane heaters that don't need electricity.I bought one for a backup in case we lose power. Only problem is when it is turned on it throws off so much heat it will melt the roof of my 7ft high GH. Any suggestions as to what I can do to regulate or reflect the heat. I think I bought the smallest one they had.

Snow...sounds like yours doesn't have a thermostat that turns the heat on and off; your's must just have settings (Low, Med, High)? The one I have will automatically turn the heat down to just a pilot light when the temperature gets to where you want it.

If it gets that hot in there maybe you could leave the heater on the floor. Is it mounted on the wall now? Maybe too high up and close to the ceiling?

Perhaps a piece of galvanized tin placed above the heater and angled over the top of it will displace the heat.

I'd also check the color of the flames...do they burn a nice blue color? And a steady flame? If not maybe there is an orifice that is missing, or perhaps the wrong one in there. Often-times those heaters work for both propane AND natural gas, and each gas requires a different size orifice. Do you still have the papers that came w/the heater that would give you that info?

Hope you're not mad at me for recommending something that is giving you a head ache...:>(

Shoe, no,no I'm certainly NOT mad at you. LOL
If my ceiling were higher I don't think it would be a problem.I can't remember the company I bought it from but this is the heater. http://www.mrheater.com/new/mh80c.htm
It has a little red handle on it that goes from light to high. Even on the lowest setting the flames throw out some wicked heat. It is made for propane only.
The galvanized tin might just work. We've only tested it out.It was bought to use in an emergency if the power went out and I could'nt use the GH furnace. So far I haven't had to use it for heating.

Ahah! I see what you mean now. I have a bigger version for ghouse for a back up. Mine has a "cap" on the top to help the heat not just go straight up tho.
I'm sure by suspending some tin over yours that will definitely keep all the heat from shooting straight up to your plastic. You should also be able to run that heater w/out it being wide open (on high) all the time. After you light it just turn the lever/knob thingamabob only half way on, that will turn it down. Or is need be maybe you can turn the propane tank knob and only open it part way to slow down the amount of gas, eh?

I'd still go with the tin, no matter what. Maybe rig a piece so you can hang in from the ceiling (when you need to) and put it a couple feet above the heater. Think that would work?

I think that's the best bet shoe. I'll look around for some tin this weekend. No hurry though as the weather is warm now but I'll get it ready for next year. Thanks.

We've never had a soot problem with the kerosene. Heat does rise so DH put a ceiling fan in the peak of the greenhouse over the kerosene heater. This should help with the melted plastic! My greenhouse is not really airtight, but snug (one layer of plastic) and the kerosene heater has no trouble keeping the greenhouse 38-42 degrees even on nights down into the teens. Greenhouse is about 350 square feet. Back up heater is electric just in case the kerosene heater goes out or the temperature outside dips and we were not prepared. Kerosene heater burns about $2 of fuel a night so that is not too bad. Of course, this temp just saves tenders overwinter and is not warm enough to keep them in active growth. Box with lid and heat mat for cuttings and the like.

Now that GH season is just around the corner, I'm skimming through last year's threads...

Our first heat source was a hand-me-down kerosene heater, and yes we had BIG problems with it - it smoked up the whole GH on its 3rd night of use. We switched to propane and haven't had any problems since. In fairness, part of the problem was that it was a used heater, and even though we replaced the wick and everything, it wasn't in tip-top shape. But I still trust and like my propane heater better :)

Yep! I agree, the propane works great in our ghouse. Wouldn't have it any other way.

Hi Shoe - the propane heater you mentioned back in May sounds exactly like what I need; can you give me the specific brand? TIA-

>>Sandy

The one I have is a "Glo-Warm" (got it at Home Depot or Lowes). I bet they are getting their heaters in now. Be sure to get one w/the thermostat, NOT just one with a Low, Medium, High knob.

Shoe - thanks for the info; I apologize for not remembering you gave me this same answer back in the spring when I was asking about heaters in a different thread!! (a mind is a terrible thing to lose...)
Anyway, I'm off to look at heaters - hope you had a great gardening year!

Great! check back in and let us know whatcha got. Hope you find one!

Shoe, got the Glo-warm, now tell me, how far away from it do I have to put plants?

Cool, tiG! Yay!!!!

I would put it where the direct heat doesn't directly go to your plants. There are blowers that hook up to those heaters (don't know if that is what you got). You don't want to blow hot air directly on the plants. If yours has no blower, never mind that part. Just don't put the plants super close to the heater.

As a test, just hold your hand in front of the heater...if it's too hot/uncomfortable for your hand then it's too hot for you plants.

To distribute heat around your g-house, a small fan circulating the air will really help lots (and also knock the potential for disease WAY down!) (stagnate air/air pockets will become nil).

Yay for tiG! (Bet your are gonna be swamped w/brug cuttings in there soon, eh?)

it's going to be full, that's for sure:) we didn't get the one with the blower, will put a small fan in there. should I put it near the heater?
ummm.....just from your experience, how close is super close? ;)

"super close" would mean putting the plants right in the 'heat wave' that is coming outta the heater.

tiG, didja get one w/the thermostat? or the "low, medium, high" control on it?

As for the fan, can't remember what size/type ghouse you have. However, a fan strategically placed will offer different options (in my mind, anyway!).

One placed on the floor will merge the cooler air into the warmer air and, as the warm air slightly cools (then falls) it'll benefit your plants.

A fan place behind the heat source, at a level equal to or just above, and with a strong force (high speed) will pull the lower cool air and warm air together and blow them across your tables of plants (or whatever is in the path).

A fan place up high, and angled downwards will blow the hot air downward (of course) and if that air hits a "target" (table of plants, wall, etc) it'll then be dispursed and benefit a given "micro-climate" in the ghouse...that micro climate will be governed by the force of the fan and by the heat offered.

Sounds educated, eh? NOT!

Walking in your ghouse with a candle will tell you where your fan/heat is going, where it is strongest, etc.

I have no doubt that within a few weeks you will know your g-house, and heater, like the back of your hand!

Congrats! You're gonna go wild in there now!

thanks so much for the encouragement. it's 12 x 24 and yes, I took your advice to get the one with the thermostat. I'm sure I'll come back and read all this 100 times in the next month:)
thanks big guy

okay, Shoe, we're still fighting with the GloWarm cutting out in the coldest of temps. Have vent, line is buried deep and we want to know if you have yours running off line from main gas tank (that serves house too) or a small tank? If it's a small tank, how often do you have to fill it up?

Good thing we have electric backup tonight.

My main heater (a big 200,000 btu)in the greenhouse has its own tank. I also run a water heater off that tank. But that heater is huge, has a blow fan, and is a commercial type heater.

The Glo-warm like you have I use in my shoffice and is on a separate tank, 120 gallon size. The shoffice doesn't get near as cold as the greenhouse so I don't run it full blast much...very seldom have to fill the tank.

I also have a tube burner propane like the one snowhermint hyperlinked to above. That one also doesn't require electricity so I use it in the greenhouse when the power goes out. (When the power goes out for extended periods of time tho I hook up a generator tho.)

I think it may be the moisture in your greenhouse that might be turning your heater off. Did you ever put a circulating fan in there? That seems like it should help matters. Or is it possible to lower the heater so it remains in cooler/lower air? Also, is it mounted flat against the wall or is there an air space between the back of the heater and the wall? If no airspace it may be getting too hot.

The gas company brought me my separate tank out and didn't charge me except for the gas they put in it. You might want to have them bring you a 120 size AND while they're there pick their brain. :>) Usually they can tell you what might be a problem (from their experience).
(I still keep thinking you need more air in there.)
If it were me I'd try all the above, then check into a separate tank, and pick brains. Sorry you are having to deal with this. :>(

Hope you check back in tho and let us know.
Anybody else out there have an ideas on this? Why her heater burns just fine for a while, then turns itself off?

Shoe, we put the vent in there like you said, just below and beside the heater. It's on a side wall mounted on wood. He took the glass front off last night and then it stayed lit. To get another tank, we have to pay monthly rental, was wondering about one of those tanks that you get for grills and can turn in and get a refilled one?
The moisture has really gone down in there, I had it opened up and fans going to dry it out some. It's still got some on the ceiling but can't get to it to dry. Yes, I have a fan going in there all the time now.
I appreciate yours and anyone else's help:)

Ohh...good! So if you leave the glass off it ran all nite?

I hope that fixes your problem.

Those small grill tanks might not burn very long. Most are 20# tanks, altho they make 30# tanks also. And at a farm store you can get 100 gal tanks for about $80 or so.

I should have a chart here somewhere that tells you how much propane burns in an hrs time. I'll look it up (when I find it).

so it will be okay if we leave the glass off? don't have to worry about anyone sticking their hand in there, and he did put the grate back on. thanks and looking forward to the chart.