Alternative heating methods for GH during power outages

I've lived in the mountains for years but never had a GH in this climate. Before I was always in areas that power or lack of it were not a problem. Anybody have any ideas for alternative heat sources that will not kill the plants( mostly orchids ). Years ago when I lived in Cincinnati I had friends that tried to add more heat with a charcoal barbecue grill when the temps went down to zero and below (the river froze solid) and they lost most of what they had. Carbon monoxide will kill almost anything and can come from wood, propane, butane etc. Anybody tried anything else? All comments appreciated.

I'm an electrical engineer (retired) from the local power company. My responsibilities included Electric System Planning and operation of the Control Center. While our reliability was quite good, nevertheless, an outage is only a question of when, not if.

I have a 5kW generator and the proper wiring and isolation equipment to run the whole greenhouse and part of the "real" house too. I stress "the proper" wiring since homeowner generators represent a significant safety threat to the lineworkers who can be exposed to lethal voltages on a "dead" line caused by the customer generator "backfeeding" the circuit. So, please, if you install a generator (a good idea), make sure you also have equipment to ensure that the generator and the incoming electrical line CANNOT be connected at the same time. In my 28 years in the electric utility business, the only thing I really worried about was having a lineman killed on my watch. I am sorry to say it did happen one time and although there was nothing that anyone could have done, it was a very sad day. Here is a link to my interconnection system. http://www.generac-portables.com/generators/pts/components.cfm

Also be sure to actually test your generator every month or two to make sure it will start and (just as importantly) that it will start and run both your fans and heating system. Also be sure you have enough fuel for an overnight run. In a widespread outage, many gas stations won't be able to pump, and those that can will have long lines.

I also have two stand-alone kerosene heaters that will just about keep the greenhouse from freezing at an outside temperature of about 15-20 degrees. Remember that the heat required to keep a greenhouse at 32 is very significantly less than at 50 or better. Growing orchids, however, poses a problem of ethylene sensitivity, and kerosene heaters are certainly not the cleanest. I am no orchid expert, so hopefully others will elaborate. I do know that ethylene will cause many orchids to immediately drop their flowers. (Ethylene is a fascinating compound in the plant world. The effects and production of ethylene by plants is fascinating.) For example, it will cause mature Bromeliads to initiate flowering.
Dave.

i have a generator too, I think larger than Dave's, and when I lose power, I just unplug these elec lines that feed the grhouse from a socket ( that runs to the house breaker) and plug them into a another socket that goes to the generator-so its totally removed from the house breaker....Dave can probably explain what setup I have better than I just did!

Also, putting Stabil in the gas in the generator, and after you run it, turn off the gas line and let the generator run until it runs out of gas is a good thing to do-that way you keep gas out of the carborator ( sp?) and it will start much easier. I can't tell you how many nights at 2 am I am out there in a snow/ice storm trying to get the generator going because i was too lazy to take care of it right and then have to listen to my brother as he bailed me out once again...lol

digital_dave and tigerlily123, Thanks so much for your input, I think you may have solved my theoretical problem (right dave, it's just a matter of time). Ethylene is neat stuff you are right. I used to use apple slices in bromeliads to get them to bloom and I ripen fruit in a paper bag the same way by putting other fruit in a bag with an apple. Anyway, I think I can use tigerlilys idea to have a generator and plug the heater and fans into it so that it would be totally unrelated to the house power. I've thought about kerosene as well but am not sure what it will do to the plants. Don't mind losing a blossom but would rather keep the plants. Thanks again to both of you.

Good suggestions by tigerlily. My main fan is hard-wired in to the electrical system/thermostat and it would be difficult to hook it up to the generator. Electric-start is a nice option also on the generator.

One other thing of paramount importance. You absoultely need an alarm to let you know that the heating or ventilating system has failed. I have one of many models made by Oregon Scientific. The picture is the in-house unit showing the conditions in the greenhouse. My unit has a remote in the greenhouse and another out in the yard, and it (of course) also displays the indoor conditions. These are wireless remotes so no wiring to mess with. ...lots for sale on-line or eBay.

The main unit is also be set to alarm on:
High temperature (a fan failure is bad news) - typically I set this at 102 - (sometimes too low)
Low temperature (a heating system failure is generally worse news) - typically I set this at 47 (gives me time to react)
Low humidity (reminds me to turn on the misting system) - typically I set this at 20 (you would be shocked to see how low the humidity can get in the Summer in the GH)

You can be warm and comfy under that winter comforter while your tropicals are dying without even knowing it. Now that you know something is wrong you can take immediate action.
Dave

The problem with Oregon Scientific devices is the range. I ordered one, as well as the "range booster" or whatever they call it. Even with this system I cannot get a signal across the 150' from house to greenhouse. I sent it back. If anyone knows of a wireless system with better range, I would like to check it out. Sensaphone is a better option, but I don't really want to bury a Sensaphone cable across my yard.

This discussion highlights the plus/minus of hardwiring your fans, versus simply plugging the device into an outlet. I prefer the plug/outlet approach for the big things, like exhaust fan and heaters, because it allows you to plug into a generator if needed.

I actually think that i have it both ways...all the wires to the thermostats, fans, heaters, outlets ect are wired into the main breaker, ( I have a cable in a ditch running to the house) and from the main breaker, I think there is a romex wire going to a smaller breaker and from there is the wire coming from that smaller breaker to the outlet and the plug thing that i switch for the generator...its a big plug thing-about 2.5" round with 4 plugs (receptacles?) on it.

Does that make sense? lol An electrician I'm not....

If you are able to plug your exhaust fan into an outlet that's certainly the easiest way. Larger fans with 1/2-3/4 HP motors are more commonly wired permanently - in my case to the thermostat controling the fan. In any case, I'm I big believer in the KISS principle. Do whatever works for you, what you are comfortable with, so you can quickly react in an emergency.

SB - I have another GH friend locally with the same problem. He is about 150 ft. I think I've seen other brands with better range. Of course the alarm can be hard wired too but wireless is so convienent.

Dave.

Davis make units that claim a range of 1000 ft. line of sight. These units are somewhat more expensive than Oregon Scientific but they have a support staff you can actually talk to if you have problems.

http://www.davisnet.com/home_static.asp

Ken

Insulate your north side. I have the big metal cans (the ones that look like you would put toxic waste in or something) fill them with water and seal them. Paint them a flat black on the inside part facing the inside of your greenhouse. I have them lined up on the north side. They collect heat during the day and at night release it back into the greenhouse. I have read stories of this method totally saving plants from freezing when the electricity goes out. Also, my hubby does heating and ac for a living and he has the almost bubble wrap looking and silver reflecting rolls of insulation. I have this on my north side as well to try to keep the heat in and protect that side of the greenhouse. Also, we do have an electric heater and big lights producing heat. But if they ever went out we do have another heater that turns on when it gets a certain temp that is ran on propane. We just have the little propane containers inside hooked up ready to go just in case in the winter. My greenhouse does not get below 60 in the winter usually.