1. The Univent Automatic Vent Opener Review

The Univent Automatic Vent Opener has the ability to lift 15 pounds and users find it as advertised in terms of its ability to work on its own without any power.

Univent buyers generally appear to be happy with their purchase, especially those concerned with the issues of their greenhouses getting hotter. Univent users feel that they have been ridden of this hassle.

Some users talked about having installed it on wooden windows and mentioned requirement of purchasing specialized screws for this purpose. The company offers standard parts for the greenhouse and the rest have to be arranged.

Other Univent buyers users felt that they had to go through the instructions quite a few times in order to truly understand them but the process felt quite easy to them.

Another user appeared quite happy with the adjustment option for the opening and temperature. One user required aluminum for his parts and felt that the opener was easily stripped particularly when it came to deposits of hard water. This user advised to utilize grease for protection of the threads before usage.

5. The Auto Vent Kit For Palram Greenhouses Review

This Auto Vent Kit, which is designed for all Palram Greenhouses, received a combination of both good and bad reviews.

The product has the ability to last in a range of temperatures and was adjustable as well. According to the user, the instructions required to place it in the refrigerator for a good thirty minutes for enabling the tube retraction.

The installation was apparently quite easy and simple. One user explained their experience by mentioning the fully open vent about fifteen minutes post the installation. The user posted about making minor adjustments in the opening temperature until the desired result was not produced.

The ease of making adjustments was appreciated by the user and ways to make the greenhouse warmer were discovered by them. The user suggested turning the product counter clockwise in case of having the opening of vent at cooler temperatures.

A user explained their experience to be quite pleasurable. According to the customer the arrival was prompt and the installation process was quite simple owing to the availability of necessary tools.

The directions have to be read carefully and the rest is a simple process. The user suggested that the auto vent should be chilled before installation. The variety of fasteners offered by the product for different greenhouse models was appreciated. Modification was easy and the aluminum offered ease of drilling.

The user has a specific case in which they had to adjust the unit till the thread’s end in order for it to start properly working. The user suggested need of improvements in the design particularly if another thread inch could be offered on the piston.The unit was said to be working with quite reliability and offered easy opening and closing at different temperatures.

Extra ventilation was suggested by the user to help keep the greenhouse from getting too hot on summer days. Protection was assured in case of cooler days and with the additional improvements the unit can be reattached and detached with ease without using any bolts or screws. 

3. The TruePower Univent Auto Opener Review

The TruePower Univent Automatic Vent Opener has many fans. One customer was apparently using it for starting up their garden seed with the help of a hotbed. The customer loved its smooth operation, especially in the unpredictability of spring climates. Users write that they don't have to constantly monitor the hotbed- eliminating a ton of daily hassle. 

2. The Sumnacon Solar Heat Sensitive Automatic Greenhouse Vent Opener Review

The Sumnacon Solar Heat Sensitive Automatic Greenhouse Vent Opener was generally appreciated by its users for its reasonable pricing.

Users felt that it was simple in terms of installation and worked in a range of temperatures.

According to a user, the loaded spring arm opens up due to force whenever the temperature goes up. It was advised that the bracket should be installed without the presence of the cylinder and the latter should be installed after full extension.

The item stops to function whenever it gets dark apart from whatever the temperature is, which is appreciated by the customers.

According to a customer, different competing brands of Sumnacon Solar are well suited for applications that require more wind but this particular model is good in case of combinations with stronger designs of openers. The adjustment ease offered by the opener is generally the favorite feature, as observed by its customers.

The Sumnacon does lack somewhat when it comes to the hardware and brackets of adapters that are used for universal installation.

One user reported to have used the product for six continuous months without occurrence of any problem.

Another user complained of missing fitting bolts along with narrowed window bracket slots which made it hard for them to drill the slots out. Its functioning, once up and running, was nevertheless appreciated and a quality fitting was eventually achieved.

Another user complained about having to make a lot of changes in their window because of the unavailability of fitting bolts.

4. The Yosoo Solar Heat Sensitive Automatic Thermofor Window Opener Review

The Yosoo Solar Heat Sensitive Automatic Thermofor Window Opener has received complaints from some of its users.

Some customers explained that it failed after an hour of operation, having sprayed oil over the greenhouse.

The customer was quite upset regarding Vendor’s refusal for any refund. 

Moreover, the assembly was criticized as well for being especially challenging. Another customer found the product to be working according to what was advertised by the company.

So, this one is somewhat of a toss-up. It will depend on your particular installation requirements and whether Yosoo has improved its design. Probably not a good buy.