Heating G'house with Kerosene heater?

Hello,

So far this year I have been able to control my g'house with electric heater but for some unknown reason this is not working any longer. I bought a new electric heater but last night it didn't hold the temp up. So we used a kerosene heater which worked great. My question being, is kerosene dangerous to the plants? We are going to have about a week -10 days where we may need to use this as it is forecast to be lows night temps. We have a lot of seedlings going really well and I do not want to lose them due to poisoning.

Thank you,
Susan

Susan, I googled and found this DG thread from 2007, http://davesgarden.com/community/forums/t/799484/
Hope this helps.

Helped alittle but still isn't not helping me make a decision. I am keeping veggies warm but I leave an rotating fan running as well as my vent open. When I went in this morning I could smell fumes and took about 3 hours after the heater was turned off to loose the smell. I just don't know what to do to keep this stupid house warm, it is so frustrating.

Susan...this may not help...but in Alaska there are two "tried and true" solutions:

Lots of people have small wood-burning stoves in their greenhouses. (I don't have one, but wish I did). You have to get up a couple times a night to add wood, but it does work.

The other solution, which I DO use, is to keep a large garbage can full of water in the greenhouse. The water absorbs the heat during the day and slowly releases it at night. (Of course, this is assuming there is enough heat during the day). The bonus of using this method is plenty of warm water to water the plants. You just have to keep filling the garbage can.

I had considered using a Kerosun heater in my greenhouse but decided against it. I will just wait until it is warm enough here.

I like the garbage can idea. I may invest in one and try that.

Thank you Ice.

Susan

I've been using a kerosene heater for several years now. Really want to switch to wood eventually. But this winter has been extremely cold. I have found that while many plants do handle it OK, certain plants (tomatoes and lettuce in particular) are effected by the fumes. The foilage of sensitive plants can look diseased. I start my tomatoes in the house so usually by the time I move them to the greenhouse I'm done with the kerosene and just using a little 'milkhouse' electric heater overnight. The electric heater along with heating pads under some of my flats works great until we get below 20degrees at night. This winter has been something else! Colder than I've seen it here in years.

I have a stock tank that I fill with water and winter my goldfish in that's set in the middle of the greenhouse with a filter and fountain head for aeration. I also keep a large garbage can for watering in there so I'm not hauling water every day. Water really is the best heat sink. In a previous greenhouse I had collected milk bottles from all my friends and neighbors (you need quite a lot, think I had something approaching 300), filled them with colored water (blue or green food coloring) and placed them under all my benches along the outside walls. It did make a difference. There's a formula online somewhere to figure out how many gallons you need per square foot. 3.5 comes to mind. But it's been along time. Try googleing it. Someone a few years ago on this forum did a trial and found that painting the milk bottles black helps.

Just wanted to add a note here. I have heated my GH with propane all winter. It does a great job, without effecting the plants. It is cheap. I use a Mr Heater Buddy with a 15lb propane tank. They actually sell up 40 lb tanks here. Next year I might get a 30lb. I recommend this type of heat to anyone.

My HGA just did a seminar about heating and cooling. They talked about kerosene heaters. One of the members had used one for years with no problems, until. He said you must take them outside and completely burn them off every so often to keep the wicks in good condition to control a soot problem. He also said that as you button up your GH to keep out the draughts you limit the fresh air and they start to burn differently more sooty. He came in one morning and everything was covered with heavy greasy soot.

HollyAnnS, we've found that's quite true. We let ours burn itself out as much as we can. Some soot is still somewhat of a problem. Fortunately, or unfortunately it's impossible to totally seal off the gh the way my DH built it so there's always some fresh air. However some days I do have to crack the door open to let out the fumes. Now that night temps are in the 30's here the electric heater is enough and I'm looking forward to not having to use the kerosene any more this winter! This summer we're going to have to wash down the inside of the gh to get rid of any sooty residue. We're building a second gh behind the 1st one and hope to link them with a shed where we can have wood heat for next year. We'll see. Lots of other projects that need doing.

I've used a kerosene heater on really cold nights. It helps to carry it outside in the morning and then turn it off. My 9' x 24' greenhouse also has about 240 gallons of water for heat storage now.

I use a propane heater & with a fan running behind it. I got a bigger greenhouse in late fall, so needed to have back-up heat. We have some really cold nights, so the electric/fan heater is there so I can sleep at night if the propane one goes out. The propane is a very nice warm heat & the plants seem to grow well with it. (2nd year of using propane). I use a 30lbs tank, which is great.

I can't store that kind of water in my 6X8 gh. I can't put enough water period in there when all the plants are in there too. I like the propane too. it worked great for me. I make sure I keep track of the hours burned so I don't run out of gas.

You folks in the south your propane might not be a big expense, but up here in northern Ohio it wouldn't be cost effective. I'm working on a project and I'm going to give hot water a try to see how that works. I've never heard of this type of heating so I'm looking for any information I can.

Great greenhouses yall.

Janet
formerly owned by Blessing & Acacia

I think if I had my greenhouse in a permanent location, I would go with a solar hot water panel and a backup gas hot water heater, then loop water lines under the plant locations. I have a
4' x 9' panel which could be set up near the greenhouse. This one was salvaged from a home remodel. I use two similar panels to heat a 880 square foot studio. The containers I have now in the greenhouse will store about 35,000 BTU on a sunny day, keeping the temperature inside about 5-6 degrees warmer. That won't be enough tomorrow night when the temperatures are supposed to drop to 20 F.

If I had a permanent big greenhouse, I would do a boiler heater

I have heated my 10x12 greenhouse with a kerosene heater for ten years now. I only use it when I'm germinating seeds, to keep the temp nice and warm, and after the seeds sprout, I use it if the temp dips below 20. Otherwise I use electric once seeds have sprouted.

When I first started using the kerosene heater, I read somewhere that plants liked the kerosene fumes (not the soot, of course). At any rate, my seedlings have alwasy done well and been very healthy. I do clean the inside of the greenhouse every year and make sure that the wick is trimmed and burning cleanly.

Last year, though, kerosene was SO expensive that I had to only use electric. Germination was very much slower in the cooler temp.

When I worked in commercial green houses we used salamanders for emergency heat. They are large metal base (5-10 gal), and a stack with a air flow control, even the fumes from these didn't hurt the plants. You had to be more careful of the CO levels than anything. Any unvented fuel heater produces some. The once or twice we used them because of mid-winter boiler failure, we aired the houses before working in them. Ric

Made it through the night with no problem, even though it hit 19 F. Used a few blankets to cover up. It's been crazy weather - we got 8" of snow in just 3 hours.

sanpedro:

I noticed your beds look to be in the ground? If in fact that is the case, how do you keep the ground from freezing? Do you have cables in the dirt?

I hope this hasn't been asked before if it was please just send a link with the answer and I'll go there.

I love seeing your GH.

Janet

I have enjoyed your converation about heating. I have always done my seed starting inside and resisted the jump to green houses. This year my inside space is overflowing with wonderful young plants and I cried "uncle" and purchased a cheap portable plastic green house. What is your threshold for how low you allow the temps to go in your greenhouses? I do not want to heat more than I have to.
Thanks,
Epazota

I try not to go below 50, but it has a few times for short periods with no problems. Some may go lower, I'm just a nervous nellie when it comes to my plants. It seems the protection from cold wind makes a huge difference. I'm still starting my seeds indoors, but they move outside once they have been up for a week or so.

Appreciate all the hints. I have only moved a few flats outside since this is an experiment. It is colder this week at night than what I had anticipated. I have put some buckets of water in the green house, but I have to use the heater. I hate using fossil fuels for my plants. It does not seem right.

I agree and have been researching ways of heating my water buckets with a solar water heater instead of just passive collection. If it works, it should reduce my need for the heater except for cloudy days.

I also do not go below 50. I also do not go above 80, these seem to be the perfect temps.

susan, do you have auto vents or exhaust fans to keep the high temp at 80? I'm still working on that, too.

Cathy,

I have a fan and a foundation vent and a window and a dutch door. I keep the oscilatting fan next to the window on a shelf. The vent and door are at the opposite end. It seems to work well. The other day when it was 80 here outside I had a harder time keeping it at 85, so I took most of the plants outside.

Last year I knew nothing about the temp limits, my Ag agent told me this year because I asked him why my seedlings got about 3 inches tall then just stopped. They were in the greenhouse for about 3 months and never got any bigger. I would water and water and let the greenhouse go up to 95. ( it was my first year having a greenhouse) Then he told me that was the problem, he said when it gets too hot the plants shut down and just stop growing. This year I have been diligent about keeping it between 50-80 and my seedlings are about 2 ft tall with lush growth! What a huge difference.

Thanks Susan, a vent down low sounds like the best idea to pull in cooler air, I can open the roof vent & wall window but it just doesn't seem to let out the hot air. The Ag info is interesting, I noticed that this week I've had more growth and it has been cooler during the day. Maybe that is the reason, I've hit over 90 quite a lot in the afternoons on sunny days.

cathy you'll probably find that cooling is MUCH more difficult than heating your greenhouse. About the only thing left in mine, in the summer, are succulents and cacti, and even they pitch fits about St. Louis summers. The good thing is, with the greenhouse nearly empty, it's a lot easier to clean and sterilize everything. =)

Eggs, I don't plan to have much in there during the summer, probably not much past the beginning of June. It will be in the shade by then, too, so that should help some?? Using it in the fall/winter/spring is my goal, I actually have a rare medical need to get out in the sunlight as much as possible, sort of like moving to Arizona but staying in Missouri. Having plants is just a great extra. I'll have a lounge chair in there in cool weather so I can be warm when I lay in the sunlight.

Yup. If it's in shade in the afternoon, then yup it'll help. =)

Interesting conversation I have learned lots. I have a very cheap super basic set up. We will see how I can maintain these goals.
Epazota

Tell us more epazota!

Sorry about the delay in response. I have started seeds inside under shop lights for several years. I had more plants than I had room for this year. I guess I had poor self control. I saw a $100 plastic temporary green house. It is small, about 4'x8'. I live in zone 4 so it gets cold at night. We have an electric heater set to go off at 40 degrees. We have four 5 gallon containers with water hoping they help with swings of temperature. I probably need more, but it is all we had around the house.

I have a pump placed in our adjacent pond that I use for water. It is handy and the water is full of nutrients.

I have tried to keep the temperatures in the greenhouse closer to the range you have mentioned. Since then the plants are starting to take off and really grow. If I continue with this success I may need to explore what kind of greenhouse I would aim for next. I will need to take some time and learn more about them.
Thanks for the help.
Epazota

Something we learned here in S.C., dig down 2feet or so before putting up the greenhouse. Then build over it. The IN_GROUND part helps to keep warmer since it under ground, less power needed to heat. and the plastic on top still lets in light and warm sun in the day time. You will find it IS less costly to heat AND cool. The ground insulates for heat and cool. Try it. It works great for me. Mekos

A sunken greenhouse - that is a great idea. Like a root cellar with a glass roof. It would definitely be warmer in the winter and maybe a bit cooler in the spring and summer. I have a small swamp cooler in mine now to move the air. It is pretty efficient here with the low humidity.

Mekos, That is an interesting idea, it would give you more head room also. My planed GH is a lean to type that will go alongside the house the roof of the GH will go under the house eaves. We will need to dig footers down and if we excavated too I could get an extra foot or two for some larger plants that I would like to put in there. Have to talk to Ric and see if it's feasiable for us.

HollyAnns If you put the gh on the side of the house I hope you are making plans to capture excess heat in the winter and pump it into the house. I have a friend who has a basment and the gh is hooked to his house. He has a computer controlling the heat in the gh. If the gh needs heat it gets it from the basement first before the heater starts. Same with the house if it needs heat it gets it from the gh before the furnace starts.

Way to complicated for me but he says it is a simple system but then he is smart lol.

Lacking a basement boy could you ever make a neat deal with a two story house or in a single story by digging down. Install a set of glass sliders in the side of the house.When the sun is hot and the temp is soaring open the slider and turn on a fan. Yep you will probably want stairs .Nice in the rain and snow.

Years ago done right it was a tax deduction but don't know about today. Ernie

Our house is passive solar with an active solar system for hot water. We also use a wood/coal stove. We don't have a basement just a crawl space under part of the house. The greenhouse will be built directly against the exterior wall with a door put into what is now the dining area of my great room. So I would have a door and window that opens directly from the GH to the house I should be able to get some kind of heat exchange with that and a fan. It would be easiest to fit it in under the eaves so that will limit the height. Not that it would be short just that I would love to grow a few larger plants and I could use the extra height. My goal for this year is to get the foundation in. I would love to have the greenhouse up and working but would be happy if we can just get the foundation in. Here is the space where it will go. It will fit between that bump-out and the brick patio the door will go in between the window and the glass doors. That kitchen window will open into the GH. It is just over ten foot from the ground to under the eave so an extra foot or two would really open up some overhead space. I haven't talked to Ric yet to see how that would work for us. He would be the one to know. Thanks so much for this idea, I had been looking up at those eaves for a year now and thinking just a little taller. LOL

Now you got the right idea, let nature work for you. It can save you a lot on heat for one, and if you work it just right, you can use the heat for your house as well and save there, plus the plants you can grow and sale or grow and use so you don't have to purchase so much for your gardens. Mekos

I plan to make mine more of a conservatory than a working GH although there will be some benches for starting seeds. That was why I wanted more height. I was thinking about a banana tree or possibly a tree fern both are on my wish list.
Edited to add:
Just talked to Ric, he thinks we will have ground water issues. I will say that it's not unusual for us to have standing water in the yard and we even live on top of the hill. We could seal the side walls but the floor will not be sealed it will be a mix of dirt stone and brick.

This message was edited May 26, 2009 8:21 PM