Hello All,
I have a small attached greenhouse with my kitchen. Which is around 700 feet. It was a screen room but i converted it to greenhouse by using plastic sheets. I was thinking to get a heater. I do not know much about heaters. Any suggestion for the safest electric heater for grrenhouse?

I read about this heater on amazon:
http://www.amazon.com/Dr-Infrared-Heater-Quartz-Portable/dp/B002QZ11J6/ref=sr_1_1?ie=UTF8&qid=1381636622&sr=8-1&keywords=Dr+Infrared+Heater+Quartz

Should i get this one? Can i operate in common power outlet without any fear?

Thanks for the suggestion,
Best

Just grab the cheapest 1500 watt at HD. Almost all are the same wattage, and there is not advantage to one that is 2 or 3 times the price. As long as they stay dry, they are good to go. if you water them, they don't take it well. $20 should get you what you need, and now with winter approaching is the season when they bring them into stock.

Ditto to what Jon said. I use an oil filled tower heater with a thermostat for my GH. It has 2 settings, 750 or 1500 watts. For my shed and garage, this year I plan on using those portable coleman heaters just to keep temps from dropping below 30 degrees.

Thanks a lot Jon & Dennis for the advice.
Best,

Great thread. I just made a hoop house and was wondering about winter heat.  Thanks for the advice.

Very nice, thanks for sharing.

Best,
Tam

In my zone 5 winters,  I heat my un-insulated garage with two small 750 watts oil-filled heaters. Both have 750 Watts and 1500 watts settings but I use them in 750 watts position.

Normally I keep one ON until Christmas and one in reserve for those months when it gets really zone 5 cold. 
Then if the two 750 watts can't keep it above freezing on some very cold periods during the deep frreze winter (when it is -25C~ to -30C outside) I switch one to 1500 watts settings during the nights. It has worked OK so far but I am insulating the garage right now.

I blame others for the 2 to 5% kill inside the garage for keeping the garage door open too long after taking garbage bags out to the to the curb.

You mentioned this was attached to the house. I personally like electric oil filled radiator type heaters for you. There are no exposed heating elements with those.

The best greenhouse heaters are the ones with a blower. I use a 220v heater with a thermostat... it all depends on how warm you wanted to stay. a small heater like the one you posted may not keep you above freezing in your area. I've been there and it's not fun when your trees get a freeze inside the greenhouse. 

The quartz heaters are your worst option.  They'll heat whatever's in the line of sight but not the air between.  The more water something has, the better it will absorb the infrared.  So part of a plant stem lit by the quartz heater might get to 70 F while another part is below freezing.  You want something that heats and circulates the air.  The oil filled ones work fine.  You can put them at the coldest parts of the room (windows or least insulated part) or put them ~1/4 of the way in to the room with something to circulate the air if it doesn't happen naturally.

Good information, thanks for sharing.

Best,
Tam

Thanks a lot!