Need Help!! I have an electrifying question!

[BVGardener]

I need to think about supplying heat to the green house and I'm probably going to have to do this for next Saturday nights' forecasted low temps. I have a couple of radiator type electric heaters that I believe would generate not only enough heat but in a safe manner and without worry of overheating the hoophouse.

My problem is that I do not have electricity anywhere near that area. Just guessing, the nearest source of electricity is at least 100' away. If I run an extension cord, what can I do to ensure the connections are waterproof? I don't want to hard wire electricity out there at this point. Any other things I need to keep in mind?

Thanks,
Jay

[jwr6404]

Assuming you are going to use more than one(1) extension I would cover the connecting plugs and/or any areas of concern with shrink tubing. I'm certain that HD or Lowes has shrink tubing in the size you need.

[dcarch]

No electricity nearby?


On a temporary basis, all entry points where water can get in, wrap with plastic shopping bags, duct tape tightly.

I would not plug in more than one heater (1,500 watt+/-) in one outlet/extension cord)

I would replace the recepticle where you plug in the cord with GFP type outlets (not expensive).

Afer everything is done, plug in the heater, a few minuits later, touch the critical points of the cord, if you feel the cord is kind of warm, than it is not good. Your cord may be undersized or the contact points may be too dirty. re-do everything.

*The above is water-resistant, not water-proof. If water ponding is expected, then you need to elevate everything above ground.
* Do not use the same plugs where you plug in computers, refrigerator, house heating system, hair dryers, microwave oven, toaster, etc.
* Some extension cord rubber gets very brittle in freezing weather.

good luck

dcarch

[Worth1]

Ok this is coming from someone with a LOT of experience in this sort of thing.

First you need to have 100’ extension cords that have12 gauge wire DO NOT use smaller cord as this will overload the wire in the cord and or cause the heaters not to run efficiently.

IF you have to use a smaller cord with the 12 gauge cord do not put it on the beginning of the run put it at the end and it should be at least 14 gauge wire and no longer than say 25 feet.
It would be best to just use 12 gauge cords.
If you only need 25 more feet then just get a 25 foot cord not another 100 foot cord.

Next, no need for shrink tubing just go to home depot or an electrical supply house and buy 3M 88 electrical tape and wrap the tape around the plug connections so no water can get into the live circuits.
If they don’t have 88 then get 33 DO NOT buy the cheap tape, get good tape as it will hold up in weather.

About 5 layers of tape will do fine

Make sure you are plugged into a GFI outlet if you don’t have one, then get one and plug it into the outlet first then plug your cords into them.
It should be of 12 gauge wire also.

Now this is for the paranoid.
If you are worried about the GFI tripping and you are asleep or in the house you can get a relay powered by 120 VAC and connect a 12 volt battery to a car horn.
Connect one leg of the wire to the horn directly to the battery.
Connect the other wire to the battery then to the common on the relay then the other wire from the horn the normally open contact on the relay.
Check to see which one is normally open while the relay is powered.
This way when the power goes off the relay will close and the horn will blow from the battery power until it runs down.

To make it simple if you use a 12 amp hour battery and a ½ amp horn you should get around 24 hours of horn blowing.

Another option would be a secondary power source then you would just connect a different power cord through the relay so when the primary power tripped then the secondary power would kick in.

Just make sure the relay can handle the amperage that the heaters draw.

Worth

[johno]

I have a similar problem, or at least I will have when I get my greenhouse built.

It's really not a huge deal to run power underground in outdoor rated plastic conduit... And by all means do use a ground fault circuit interrupter like dcarch said! You wouldn't need the heat very often, but the electricity would be useful for other things like lights and timers.

For my situation, it seems like a small propane heater fits the bill better than electric. I'm in north Arkansas, and we get a total of about two weeks or so when I'd have to run it (solar heat would do for the rest of the time.) Seems like in zone 8 it would be even less. You can get a little burner that screws on top of a small bottle, or use something like a turkey fryer or camp stove that uses the propane grill type refillable bottle. Depends how big your hoophouse is...

When I worked at a nursery in zone 7, we used a propane grill to heat a 40 x 100 greenhouse to about 55 degrees...

[Worth1]

For a small green house simple heat lamps would be just fine with a small fan to circulate the air.
you really only need to keep the plants above freezing.
In this way the plants are better acclimated for the finale planting in the spring.

I turn off the heater vents in my extra bed room where I start my plants and it gets to around 40 degrees in there.
In this way they do not go through cold shock.

Worth

[TomatoDon]

Run a propane burner. They are pretty cheap. Even a fish cooker if you have one with a bottle of gas. You can even set a wash tub of water over it and it will put off a little steam through the night which seems to help keep the chill off. That's the way I used to do it in my greenhouses.

Don

[BVGardener]

Many thanks to all for the feedback. Short term, I'm think I will go with the propane ideas. It just so happens that I have a propane fish fryer (had several years, never used it) and what I will do is set my weather station alarm to go off at a certain temp during the night. Then I'll just go out and turn the propane burner on and let the temps get back up to a decent level. I will probably start by turning the propane burner on about 10:00 pm and let it run for a while until the temps inside the hoophouse go up a good bit and then see how long they hold. That should get me through this weekend. Not sure what the forecast is beyond that.

At some point though, I would like to have the electric radiators hooked up even if it was only one of them. These are the oil filled type and they have a thermostat I think....have not used them in a while. They would be something that I could let run inside the hoophouse without any worry.

Now that I think about it, I could tap into the electricity at my water well and run conduit from there. I would still be looking at close to a 100' run though. I've been down the electrical road before - wired the electrical meter pole at my house, trenched and ran wire/conduit to the house and passed inspection on both of them. Then ran wire/conduit to the water well and had to replace the pump and rewire that too. Still, I can't help but think about all of those tree roots I would have to go through if I run conduit to the hoophouse.

I think running conduit will ultimately be the way to go but I'll probably have to run an extension cord out their temporarily if the temps stay low for several days. I've still got some of that special electrical tape I had to use when I replaced the water well pump that is used for making electrical connections that will be under water. Good point!! Definately need to use GFP outlets.


Thanks again,
Jay

[dcarch]

May be Santa will get you a remote temperature reader/alarm?

dcarch

[TomatoDon]

And if the power goes out you are up a creek.

Also, and we did this some too, is get some of those inexpensive kerosene heaters. They run pretty cheap. I'm not sure the size of your greenhouse, but keresene heaters or fish cookers with bottled gas are the best for places that don't have ready access to electricity. And again, if the power goes out, you are up a creek. Also, I've seen them put a wood burning heater in a greehhouse, pipe it out the top, and the pipe even helps keep things warm all up to the top where it vents out, rather than venting it straight out the back near the wall. If you have a good access to wood, and won't be needing heat many nights, then this may be a good choice. A wood burning heater puts out the most heat, too.

Hope this helps.

Don

[BVGardener]

My hoophouse is 16' wide x 24' long and about 6.5' high at the center.

The wood burning stove idea reminds me....it just so happens that I have one. It weighs about 500 pounds though and of course, it is located about 150' from the hoophouse but I could move it there - it's not in use.

It looks like I will just need to get through Saturday night and Sunday night. The weather forecasts are all over the place....the local forecast is for mid thirties both nights and weather.com say high twenties. Either way I'll have to be prepared.

Jay

[Worth1]

With all of this talk about wood stoves and gas heaters and so forth, I would like to mention ONE THING!!!!!!!

I know this is out there but please be careful going into the green house as the oxygen levels may be low and the carbon monoxide levels high.

I know that it probably has plenty of ventilation but be careful.
I would hate to hear on the news that, "Area man found dead in tomato house after succumbing to CO poisoning."


Worth

[BVGardener]

Or it might read:


"Area man found dead in tomato house with a Brandywine in one hand and the temperature gauge in the other after succumbing to CO poisoning."

Jay

[dice]

I was thinking that if you had one of those wall-mounted
instant hot water heaters in your house, you could string
together a set of salvaged heater cores or a radiator or two,
run a hose out there from a hot-water outlet in the house
(need some adapters for all this to get the appropriate
sizes for the garden hose, and pile something around the
hose to keeping it from losing any significant amount of
the heat on the way), and just turn the water on at night.
You can put a short hose on the other end and let the water
drain to some innocuous part of the garden.

No fan, so only convection would move the warm air
around the greenhouse.

Not that this sounds more practical than other methods,
and if your power goes out, the instant water heater
goes out with it. No CO, though.

[orflo]

And this could be the future: insulation means no heating, or less heating, depending on your climate:
http://www.solarbubblebuild.com/
Frank