There are three types of automatic door closer available in the market today. Depending on the weight of the door and how you intend use it there’s a right type of door closer for you to choose from. The most common type is the spring loaded door closer hinge pin door closer which are good for light applications. Perfect for light weight doors like patio doors which is usually made of lightweight aluminum frame with mesh screen covering almost half of it. This door closer is usually made of aluminum tubing or cylinder with only the push rod exposed while the spring is hidden inside. The principle used is very simple, a spring mechanism pulls the door with a small tension and when you open it additional tension from the string is generated which force the door to close when released.

The common problem with spring loaded door closer is that the push rod can be easily bent if not installed properly or if you open the door too much. Also the piston rod bearing or bushing at the front end which absorbed the linear load wears overtime.

Another type of door closer is the pneumatic door closer. They are very similar to their spring loaded cousins with respect to load capacity and overall look. It also uses the same aluminum tube frame and has a piston rod. The main difference is that it uses pressurized air instead of springs which is generated when you open the door compressing the air inside then pulls and close the door when you release it. Also the internal construction is slightly different. In the spring loaded door closer there’s no rubber seal on the piston or it is not air tight while in pneumatic door closer, a rubber seal is installed to prevent the air from escaping. Without the rubber seal to hold the air pressure or when it’s broken will make the unit useless. Also the internal surface of the aluminum cylinder is mirror polished for smooth operation and to prolong the life of the rubber seal and the unit itself. Since the air is compressible this type of door closer has the tendency of slamming the door if not properly adjusted.

The last type of automatic door closer is the hydraulic oil filled door closer. This type is the most reliable and toughest among the three. It also has a very different construction and mounting construction compared to the other. While the spring loaded and pneumatic door closer is placed at the side of the door, near the hinge, the hydraulic type is installed at the upper part of the door. It is best to use in heavy weight doors and is commonly use in front doors or main doors. The closing speed is adjustable with the turn of the screw. With the mounting template (to mark holes for drilling) and installation instruction included in the package making it very easy to install (drill required) and doesn’t need a professional to do them. Unlike pneumatic air, hydraulic fluid is not compressible, so, it is possible to adjust the closing of the door at a very low speed and smoothly.

There are also other types of door closer like the motorized door closer. Actually it’s not only for closing but for opening as well which is very convenient for hands free, disabled and handicap access. This system uses a 24 VDC motor to operate and controlled by a microprocessor which enables you to open and close the door both manually and automatically. The encoder which is coupled to the DC motor detects the angle of the door at all times, meaning the encoder can determine if the door is open and how much and reacts accordingly. Compared to non electric door closer it’s pricier cost around 1.5k USD and probably hard to maintain because of too many moving parts and definitely needed an expert technician to install.