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Indoor growroom electrical hookups

I want to make plans to get outta this condo and into a house with an unfinished basement where I can build a large solid wall indoor greenhouse/grow chamber that I can walk in.
The highland chamber would be 10 x 20 with two 1000w Metal Halides, 5000-10000 btu air conditioner, several circulation fans, two humidifiers and a humidistat. Probably about 2500-3500 watts total.
The lowland chamber will be the same lighting and humidity minus the air conditioner and fans.
Will I be able to simply plug all this in or will I need to have some electricians hook up something special to allow the house to handle two grow rooms sucking up aproximately 5000W?

I suppose a visit by the DEA would probably be customary as well!
wow that doesnt seem like it wouldnt be to much
lol jk
Basically your wanting to know how many amps everything is pulling. So you need to add up the total for all the items on the circuit and make sure it doesn't exceed the circuit breaker and wire (the wire should be matched to the breaker but still worth checking.)

Most likely the airconditioner will need to be on it's own circuit. This will be easy to tell since it should have the amp rating on it somewhere.

As for lighting and other stuff that doesn't have an amp rating..
watts/voltage = amps

so a 1000 watt mh lamp will pull
1000/120 = 8.33 amps

I suspect the problem you will have is that you will only have a single existing circuit which may be wired just for the basement or might also include a portion of the house. Most household circuits are 20amp. So to answer your question.. You will need more circuits put in most likely.

For the highland room your probably looking at a 20amp and a 30amp so you have a little breathing room. The lowland you would be comfortable with a 30 since your not running an AC unit.
i dont understand a thing you said
Thanks Tony! I will have to include an electrician in my home buying plans! Perhaps have a house with two basement grow rooms built in...

I've already blown my circuts at this condo a few times! I've had to stagger the timers so all the terrariums and fishtanks can run in one 24 hour period without the power going out in the apt.!
The good news, if it is an unfinished basement then just be sure the circuit breaker box is easilly accessible and has room for more breakers. As well as having a good supply from the power line ie 200amps. It is very easy to add a circuit when access is open to the breaker box and the final point for the outlets. So even if you did need an electrician to run some circuits it shouldn't be overly expensive.

Keep in mind that any outlets inside your grow room should be ground fault outlets or wired to a ground fault breaker.

The rooms will be the same setup as my terrarium size chambers except built with GH polycabonate walls (cheaper and sturdier than that fiberglass shower wall) and double layer pond liner for the flooring.
Inside there will only be the thermostat, humidistat, fans and humidifiers and the AC output (on the highland one). The power plugs for these (and the lights) will all be plugged in outside the rooms where it'll be dry. The lamps themselves will be above the rooms shining through a  sheet of glass on the lid/ceiling (with another fan blowing over the lamp to keep the temps down-for the highlanders).
hey swords,

I run a 1000 watt mh, a large AC and a couple of humidifiers and fans in my basement. the AC only runs at night when the light is off so it isn't an issue as far as current pull (make sure you don't buy the nice electronic ones, they won't work on an autotimer). The simplest thing to do is plug each metal halide light into a different socket running off a different circuit breaker and you will be fine. With an 80% efficient magnetic transformer the 1000W lights only pull about 10 amps, not too bad. If your greenhouse is about in the center of the basement you will find that the electrical outlets on either side are most likely on different circuit breakers making life easy for you. I do find it necessary to leave a basement window open.

Believe it or not, a nice vacuum cleaner from walmart pulls more current than a 1000W halide so don't be too worried.

By the way, depending on ceiling height and greenhouse height, you may find the fan on the MH light to be overkill. I have a foot above and below with no fan and my highlanders are happy as clams.

  • #10
Thanks Joseph!

I have a 400W MH over my lowland showerstall chamber in the living room and it doesn't need the fan setup that I built into the light box (I assumed I would need to fan to keep the plexiglass lid from melting) but infact the 400W MH doesn't even heat the terrarium like the flourescents did (it is a remote ballast type however).
I figured that the 1000 watters might be too warm though. Maybe not! That would be nice!

Can anyone explain to me how many watts equals an amp, or how to figure out amperage? I thought 1000 watts equalled 1 amp but Joseph said a MH will draw around 10 amps. Is every 100 watts an "amp"?
  • #13
Here is my contribution to stupid questions:
When using a AC unit to cool a highland chamber in a basement, does it have to be fixed into a window , or can it just be fixed to the side of the chamber with the back just inside your basement?


  • #14
A window AC unit doesn't "have" to be out a window but AC's will drip as they pull the moisture out of the air. A pail beneath the rear of the AC unit to catch condensation is a must.
Other than not sticking the rear of the AC out a window (as I do now) I plan to set up everything else the same that it is now. Have the AC outside of the grow room (but at head height so the cooling effect would be better than it is for me now) and the output directed through a much shorter length of duct tube with a humidifier interception so that the AC will not dry the cold air when it blows into the chamber at night.
  • #15
As far as a dripping AC, I made the floor of my greenhouse out of linoleum (sp?) and tilted the AC down a few degrees so that it drips into the greenhouse.  The water evaperates off the floor pretty quick and helps a little with the humidity.

My AC is not hanging out the window, but I do keep a window open during the summer.

swords, figuring that you are going to be using standard magnetic ballast and MH bulbs (not the expensive pulse start systems) you can figure on your system running at about 80% efficiency, meaning that for every 1000W of MH light your transformer will dissipate about 250W of heat for a total of 1250 watts.  Watts/volts=current.....1250W/120V~10.5Amps

The new overprices pulse starts only run about 84-90% efficient and you have to buy thier bulbs, I wouldn't bother.

1000W bulbs get very warm...very very warm...but if you don't touch it and the air is allowed to freely circulate around it then there is no prob.  The end effect is that you will be putting the equivalent of a 2500W heater in your basement and running it all day.  With free air circulation you aren't going to melt your greenhouse, but surely you can see that basement ventilation will be necessary to keep temperatures from rising.  A simple exhaust fan or open window works for my little basement.

What is really neat is if you run the lights past 8
0pm or so and then go outside and look at the view your neighbors get....."o ya, he's growing pot"....

  • #16
ummm...that goofy looking head isn't supposed to be in my last post.
  • #17
I know!
That's what I'm most afraid of is the neighbors or cops thinking exactly that and come busting in and destroying plants cos they have no idea what they are.
Judging by the newspaper and TV news MN police are not known for knocking and kindly asking to view the premises. Perhaps if I were to hang a big sign next to the door advertising my website "Jurassic Gardens carnivorous and exotic plants". Perhaps they would knock instead of come through the front door with a battering ram!
It would be no problem to give a tour (I'd talk their ear off and they'd soon be rolling their eyes like the people at work do when I start in with the plants) but I don't want my place destroyed and get some cheezy apology letter from the cops when they've killed my priceless plants.