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Model # 701338

Internet # 202075434

2-3/4 in. x 15-3/4 in. Automatic Vent Opener

This item has been discontinued.
The Home Depot no longer carries this specific product.

$57.38 /each



Model # 701338

Internet # 202075434

The Automatic Vent Opener was designed to automatically control the temperature, humidity and provide additional ventilation when needed, making gardening easier. As the air inside the greenhouse warms, the vent gradually opens to allow the correct amount of air flow into the greenhouse and closes when the optimal temperature is reached. The vent arm was designed with a metal cylinder containing wax which expands when heated to push a piston, which raises the window, as the air gets warmer, then contracts as it cools, closing with the use of a spring and resetting the piston. All you need to do is to install it on your roof vent window and it automatically starts working. The Automatic Vent Opener operates without the use of electricity and works with all our Greenhouse models only.

  • Assembled dimension: 15.75 in. W x 2.75 in. D x 2 in. H
  • Opens roof vent automatically as temperature warms for air circulation and heat relief, Closes when temperature cools
  • Solar powered, heat activated - start opening point: 54-59 F degrees
  • Mechanic system - no electricity is needed
  • Suitable for all Palram greenhouses and easy to install


Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
15.75 in 
Product Type 
Product Weight (lb.) 
1.5 lb 
Warranty / Certifications
Manufacturer Warranty 


Rated 4.5 out of 5 by 15 reviewers.
Rated 3.0 out of 5.0 by The instructions are lacking detail I made a custom bracket to mount two of these in a Greenhouse from Harbor Freight. I could not find a photo of one of these mounted with the vent closed. The two I purchase worked per the instructions, but with the units at the halfway point on the adjustment and at 60 degrees the ends that are mounted to the frame and the vent are about 8 inches apart. I was not able to mount them without making the bracket. See the photo attached. Pay attention to the initial preparation where the unit is placed in the fridge for a while. This allows the rod to free up from its initial stuck postion. May 20, 2015
Rated 5.0 out of 5.0 by makes life easy and saves your plants Pretty straightforward installation and it comes with parts to fit most Palram greenhouses (I think there's only one model it doesn't fit). Although opening and closing the roof vent is easy, remembering to do it is hard. Lost a lot of good plants last year just because they were cooked in a closed greenhouse. Now I don't have to worry about when to open and close the vent, and it has made things so much easier - not to mention that the plants are a lot happier now. June 8, 2015
Rated 5.0 out of 5.0 by A handy accessory! I recently purchased the 8’x8’ Snap and Grow greenhouse and purchased this at the same time. I am so glad that I did! The temperature in my area fluctuates pretty often and I am a little too short to reach the standard arm that came with the greenhouse, so this was just what I needed. September 28, 2010
Rated 5.0 out of 5.0 by Just what I wanted! Wanted a hobby greenhouse to keep the rodents from eating all my veggies. If you take the time to sort all the parts so you can find them before you begin, the greenhouse goes up quite easily, although it takes a good 8 hours with 2 people for this particular kit. It is very substantial when together and I just love it. Stays quite warm inside even on chilly nights. The shed is great for all my tools. Couldn't be happier. May 7, 2014
Rated 5.0 out of 5.0 by Works great Easy to install and works great. One thing I have just noticed is that if you put a heater in the greenhouse the vent arm will open if it gets above 65 inside. We'll see if 30 degrees outside what happens. So it is really responsive to temperatures. November 11, 2014
Rated 1.0 out of 5.0 by We love the greenhouse but the vent arm does not attach The directions in the vent arm box do not match the parts that came with it. And so there is no way to attach the vent arm to the greenhouse. We even drove to another town to see the one of the friends who recommended it to us. Their vent arm parts were completely different from the ones we received. I hope this is a temporary problem. June 8, 2012
Rated 5.0 out of 5.0 by Best Purchase Ever This product is absolutely wonderful. I would highly recommend it to anyone, it works perfectly. I don't have the hassle of opening and closing the vent daily or being concerned about the temperature of the greenhouse if I am away from home. October 29, 2014
Rated 4.0 out of 5.0 by good features but product is intended to fit too many greenhouses The screws intended to fasten the product to the window/vent will not penetrate the thick metal without drilling a hole to get them started. Otherwise, useful and fairly easy to put up. December 15, 2013
  • 2015-08-26T09:18:49.833-05:00
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