If you are about to purchase a professional Vacuum Sealer, there are some differences between chamber and chamber-less machines you need to know before making a decission. We'll try to explain them.
Vacuum Sealers with chamber create the vacuum in a closed space, resulting in a more accurate vacuum. In technical terms, the vacuum created inside a chamber ranges between 3mb and 8mb. However, in simple or external Vacuum Sealers, being in open atmosphere, it does not exceed 130 mb pressure.
Another difference lies in the type of bags. For the external vacuum packing machines, the bags have to be special and are called embossed bags. They are composed of two different materials, one side is smooth and the other side is embossed. The side with the embossed texture imitates a honeycomb and technically, it is the specific bag to create outer vacuum. On the other hand, the bags for the Vacuum Machine with chamber can be normal, retractable, laminated, or even embossed.
In terms of space, the Vacuum Packing Machines without chamber tend to be smaller and more manageable than the ones with chamber.
Another important factor when choosing the type of Vacuum Packing Machine is to know the future use of the sealed products. If our goal is to cook food under vacuum or “sous-vide”, products sealed under External Vacuum machines will not do the job, since the embossed bags would lose the vacuum.
For maintenance, simple machines require less intervention since there are no oil changes or change of gaskets for the air-tight chamber seal.