Hi there! I'm running power out to my greenhouse because i need a fan and i am going to get a heater for the winter to keep it above freezing. The electrician asked how many outlets and where I want them.
Before I hire him I wanted to give this some thought and i figured I'd ask here. If anyone has outlets in their greenhouse, how many do you have and what do you use them for? i imagine grow lights, heat mats, fans and a dedicated outlet for a heater (depending on how much power it uses). Am I missing anything?
by c0okies
6 Comments
Shade cloth on the outside
Add up the amperage of all of the equipment you plan to run. If you are in the USA, take the wattage of the item and divide it by 110. You have now calculated the amp draw.
For example, a 220 W light uses 2 A. If you have five of these lights that would be 10 amps if they are all being run at the same time. In reality, LED lights and grow mats typically draw less than 30 W, but you will need to read the labels on your equipment and add up the amperage.
You can also show all of the equipment to your electrician and ask them to do the math, or to verify your math.
Once you have the total amperage, then go back to your circuit breaker panel and if you have an open circuit, read the amperage that the fuse is rated for. It will probably say 15A. This means it’s rated to handle 15 amps. Compare that to the load that you calculated.
Now that you know what you can power, consider where the equipment might be placed in the greenhouse and use some chalk to mark the outlet locations. It is always best to plug equipment directly into the outlet rather than using some type of extension cord.
in your case, I would consider putting an outlet in the ceiling for the lighting, often times lighting can be daisychained together, so you may only need one outlet. You will also want an outlet on the shelving for your heating mats. Your electrician could very easily install side-by-side receptacles, giving you four outlets in the shelf area.
If you are installing an electric heater, you will want to know detailed information about the amperage of the heater. Overall, this small greenhouse, I would expect that you would use two circuits. One would be for the heater and one would be for your lighting, heating mats, boombox. Especially if the heater draws more than 10 A. Your electrician can help guide you through that process.
How many outlets? More than you think you’ll need. Like the other person said, add up what you plan on running and give yourself some room for extra and then position extra outlets for it you want to move stuff or reposition or add a light etc.
My gh is 20×11, I put in a 60a sub panel and I have a 40a circuit for a 240v 25,000 btu heater, another 20a circuit dedicated to an exhaust fan which is a switched outlet controlled by a thermostat. I have 3 other 20a circuits for fans and thermostatically controlled roof vent and louvered intake. I also run a dehumidifier. I have no lights. It’s over-wired but I like flexibility.
I ran power to my greenhouse last year. I did all my main appliances (exhaust fan, circulation fans, blower, lights) off switched outlets. That way if I ever have a fan go out, I can buy a replacement and plug it in and hang it and its ready to go, its also great for expansion, like adding another fan, just plug it in, its on the same switch.
As far as how many, I’d say having one every 5 or 6 feet on the walls should allow you to plug in anything and an outlet should be within reach.
I set up my greenhouse about a year ago and kinda wish I’d put in an extra outlet or two, so you’re smart to plan ahead. Basically, I’d say you can’t have too many outlets, especially since it’s way harder to add more once everything’s done. Maybe put in at least one on every wall or wherever you think your stuff will go.