Greenhouse safety

[Tropicdoc]

So I know some of you use greenhouses. I use spring gardener greenhouses over planted beds with supplemental heat. I use small utility space heaters from Walmart plugged into an extension corId I have a wireless smoke alarm hanging inside that communicates to a smoke alarm in my bedroom. I also have a wireless temp probe with an alarm to sound at 105 F. This communicates to my bedroom also. Does anyone have comments on the safety of this setup or suggestions on how to make it safer? My wife is hounding me about this. I told her people have heated greenhouses all over the world, so there's gotta be a best way.

[KennyRE317]

I would be interested in this as well. although I don't have the room to build an actual green house and use those smaller hobby greenhouses I've considered giving them a little heat

[NorCalWill]

Maybe there is a safe way to use a space heater in a green house, but many fires are caused by them and hundreds of people die every year from space heater related fires.

I sometimes use a space heater to warm my small green house for short periods while I am nearby, but unplug it when I leave.

The biggest warning that is printed right on the heater is to never use an extension cord.

Heaters draw a lot of energy, and extension cords can overheat and cause fire.

Maybe an electrician can give better advice.

[richnorm]

Do you use circuit breaker?

[Patrick]

I've only used incandescent lamps or heat lamps. They put out 90% heat and I figure the light can't hurt. I avoid the space heaters because I think they put out too much heat and dry things out maybe a bit too much. I am not experienced with the Wal Mart heaters, though.

My only goal with the greenhouse (well, it's a shed actually) is to keep the temp above 40 degrees as to avoid the freeze. I'm not growing anything too tender, though.

The safety measures are a good idea. Problem is if there's a fire it's too little, too late. The temp probe is a great idea.

[KennyRE317]

I'm not sure if it changes with a more quality greenhouse but I've only had experiences with the small flimsy amazon/ebay ones and noticed that it doesn't do anything in terms of keeping The temperature any higher than outside. I put 2 thermometers next to each other with one inside the greenhouse and the other outside and there was the same reading on both. I still use them to protect msmaller plants from the wind and when I do get a bit of direct sun it helps warm things up slightly

[Tropicdoc]

I agree once the sun goes now the greenhouse holds no heat. It does heat up nicely on a sunny day.... About 15-20 degrees above ambient temp. I saw the no extension cord warning. I wonder if a heavier duty cord would be any safer. I do unplug the heater when no one is home.

[_Keith]

I did this for many years, with the only issue being the breaker tripping. Now some space heaters are safer than others. In later years, I used the oscillating ceramic type which is far less likely to cause issues relating to fire.

[Cindy Adair]

In my attached, glass and wood greenhouse, I have used 2 small utility heaters. I don't use extension cords and am careful not to get them wet. They sit on my interlocking paver floor and I make sure to have clearance all around them as directed in their instructions. I have had to replace them every few years, but they are usually around $20 each. The thermostats aren't very accurate, but other than that I have no complaints over the 15 years I've enjoyed this 12 x 20 foot greenhouse. They are unattended when I'm gone, but so far so good.

Of course mine is a permanent structure we built to code so probably not applicable to your perhaps seasonal/temporary structures?

[Tropicdoc]

This information is really good. That's why I started this thread. So, Keith, why is the ceramic heater less likely to cause fire? Does it draw less current? Maybe send me something showing the type of heater your talking about. I like the Wal Mart heater because it has a lower setting (1300 W) and a thermostat which I figured has less of a fire risk.

I do keep the heater dry. It is sitting on a cinder block and has clearance around it. I rarely water the plants in there. They soak up water from the ground around the greenhouse. It has anti-tip and overheat shutoff. I am plugged into an exterior GFCI outlet that of course is attached to a breaker box.

[Tropicdoc]

I went to Homed Depot at lunch and got a 12 gauge heavy duty 25 ft extension cord to use. From what I've read and calculated this should prevent any overheating of the extension cord. Before, I had a 50 ft medium duty cord.

[KennyRE317]

heavy duty cord would be perfect, but the fact that you're plugged in directly from an outdoor GFCI outlet on it's own dedicated circuit makes it pretty safe

[Alicehunter2000]

Used to use a heavy duty cord plugged to a GFCI outside outlet. Small space heater on concrete blocks and an ocillating fan place in front of the heater a couple of feet. This would keep a portable "parking garage" above freezing. BTW....I would be interested in selling the portable parking garage since I can't use it anymore at my new house. You can overwinter a large amount of plants and take it down/store it in spring. It comes with tie downs and has withstood some strong winds. I'll see if I can locate a picture.

[Tropicdoc]

Yes The GFCI outlet is a dedicated circuit that I just had installed. In the summer it is for my mosquito misting system. It is for the heater right now.

David, the Spring Gardener greenhouses are basically the same as the "parking garage". The cover is transparent, though, allowing the sun to heat the inside to 15-20 degrees above outside temps and promote growth. In fact, I have 4 potted coconuts in there right now, still pushing spears.

These greenhouses are way easier to use than any other cold protection methods. They go up once, stay up, then come down once. No running around crazy when a front comes through.

Yeah, yeah there are great palms that are rated for zone 9b, but I like my tropicals.

[MattyB]

I've got a question:

I don't heat my greenhouse, but I do have 2 small oscillating house fans that run on a timer during the day. I have them plugged into a GFCI outlet with small gauge home extension cords. The cords are up high and don't get wet, but I'm concerned about possible overheating of the cords or fire hazard for whatever other reason due to the cords. Why would these cords be ok to use in the house, but not ok in my dry greenhouse? Or is this just a concern for heaters? What if my fan rusts up and causes resistance, would that overheat my cords? Any insight is greatly appreciated.

[paulgila]

tropicdoc,you & Kenny look exactly alike! never noticed until I saw you (your avatars) together in this thread.

ok,i admit that was lame.

[_Keith]

tropicdoc,you & Kenny look exactly alike! never noticed until I saw you (your avatars) together in this thread.

ok,i admit that was lame.

[MattyB]

pshhhh, 17 people died in greenhouse fires while you were writting your post Paul!

[KennyRE317]

Matty, you should be fine ... most of the time people put heavier duty stuff outdoors so those small extension cords aren't recommended. even if it's outdoors and the cord itself sees some water that's usually not a big deal but the thick outdoor ones just have a lot thicker of a sleeve to help resist against cracking, rips, and the occasional cuts from equipment or being dragged around

[KennyRE317]

it's funny because i have avatars in all the other forums i participate in

[Patrick]

Extension cord fires in houses, a lot of times, start if the prongs aren't plugged all the way into the receptacle or work loose over the years. Dust and debris get between the hot and neutral prongs, arc, and start a fire. Same with the power strips- especially with power strips; so much debris builds up on them over the years (after you've stuck it behind your couch and forgotten about it) that arcing actually happens across said debris and anything nearby eventually becomes a fuel source. Dust bunnies burn goooooooooood.

Newer homes actually have breakers that sense this arcing and trip when it occurs. It's a technology that's been put in new homes for probably 10 years or less.

Your fans draw a very small amount of current and will probably never be a problem. You're probably using 1/4 the capacity of a cord with 16 gauge wire. If the motors on the fans did seize, the breaker would trip most likely and that would be all. Space heaters on the other hand use a LOT of electricity for their size and it is very possible to use too small of an extension cord. The extra power causes heat in the cord wire if it is improperly sized, the heat breaks down the insulation, the insulation falls apart, wires short out and *blam-o* you have a decent spark and a tripped breaker or blown fuse.

You're fine with your fans, but I would recommend to continue using the GFI since you're in a wet-ish situation. You'll probably never need what it was designed for, but it's cheap insurance. Those gfi's are a common fail item, fyi. They just stop working, though. Nothing too dramatic.

[MattyB]

Thanks

[MKIVRYAN]

Can someone tell me a brand for these wireless remote smoke detectors or a link to them. I was unable to find them on amazon. Thanks

[JT in Japan]

I have a portable, self-contained, oil-filled radiator of sorts (see pic) which, as the name implies, radiates heat without any exposed heating elements. It's in my 10x12 sunroom, dry, plugged into a power bar that's plugged into a household extension cord. After reading this, I see that the power chain is a problem I'll have to deal with, but I wonder about the heater itself? I don't know that it gives off a lot of heat, but it manages to keep the sunroom about 12-14C, when outside it's getting down to 5-6C at night. Has anyone had any bad experience with radiators?

Cheers,

JT

[Tropicdoc]

Kidde RF-SM-DC Smoke detector

[palmsOrl]

I am in no way officially recommending that fellow enthusiasts utilize space heaters to heat their greenhouses. I have, however, used an indoor space heater (actually several over the years) in my fairly small greenhouse for the last 12 years and have never had a problem with either heater failure or safety issues. The heater and plug/connection gets somewhat wet as I water (many times over years and years) and I have never had a problem whatsoever. Earlier on, I was occasionally worried and kind of puzzled at my lack of issues, but now I just conclude that it is a great (by far the most economical and practical) way to heat my greenhouse. That said, proceed at your own risk and take precautions to ensure your safety.

Mine has been on despite the heat since I have coconuts to germinate and ultra tropicals in the greenhouse and I figure it couldn't hurt. 70s at night and 100F by day.

[edbrown_III]

I have a portable, self-contained, oil-filled radiator of sorts (see pic) which, as the name implies, radiates heat without any exposed heating elements. It's in my 10x12 sunroom, dry, plugged into a power bar that's plugged into a household extension cord. After reading this, I see that the power chain is a problem I'll have to deal with, but I wonder about the heater itself? I don't know that it gives off a lot of heat, but it manages to keep the sunroom about 12-14C, when outside it's getting down to 5-6C at night. Has anyone had any bad experience with radiators?

delonghi-safeheat-electric-oil-filled-radiator-ew0507.jpg

Cheers,

II tented one side of the house where I have the Jubeopsis and triangel and use this type of heater---- it gets hot but never really burns --- I have done this when we had all those nights in 20'sF a few years back. [[[[[[ use a heavy duty cord and feel the cords after a few hours to see if they are h0ot. ------ one thing everyone needs to know about breakers are they are mechancial devices and if they trip a bunch of times their springs will break or become brittle and frequently trip but are reallly on. ----- if you hear buzzing or the breaker is real hot you need throw it bak -- you can burn wall wires and start a fire in severe cases.

Best regards

Ed

JT

[Tropicdoc]

Nice disclaimer! I feel much better hearing others experiences and now that I have a larger gauge extension cord. Looks like I will keep my 8 foot tall zone 10a jungle!