Chamber vs External Vacuum Sealers: Which Does a Kitchen Need?

How the two types work

An external sealer, also called a suction or edge sealer, works with the bag outside the machine. You lay the open end of the bag across the seal bar, close the lid, and the pump draws air out through the bag's textured channels before the bar heats and seals it. Because air is pulled out of the bag itself, the bag must have an embossed or channelled surface for the air to travel through.

A chamber sealer holds the whole bag inside a closed chamber. The pump removes air from the entire chamber, so the pressure inside and outside the bag drops together; the seal bar then closes the bag, and air rushing back into the chamber presses the bag tight against the food. Because nothing is sucked out of the bag directly, liquids stay inside it and smooth bags work.

Some commercial external sealers use a retractable nozzle inserted into the bag instead of relying on channels, which lets them work with smooth bags and larger packages. They sit between the two main types and are mostly found in packaging operations rather than restaurant kitchens.

Chamber vs external, side by side

The differences come down to liquids, volume and running cost. Here is how the two compare on the points that matter in a kitchen:

• Liquids and wet foods: chamber sealers handle soups, sauces, marinades and brines; external sealers draw liquid toward the pump and struggle with anything wet.
• Bags: chamber sealers use smooth pouches; external sealers need embossed or channelled bags or rolls.
• Speed and volume: chamber sealers seal one or several bags per cycle and suit continuous use; external sealers are slower and suit occasional use.
• Vacuum level: chamber sealers reach a deeper, more consistent vacuum; results from external sealers vary more with the bag and the product.
• Size and weight: external sealers are light and portable; chamber sealers are heavier and need a permanent spot on a counter or stand.
• Purchase and running cost: external sealers cost less to buy; chamber sealers cost more up front but usually less per bag over time.
• Maintenance: external sealers need seal-bar care; chamber sealers with oil pumps also need oil changes.

Which kitchens need which

For most restaurants that vacuum pack every day, a chamber sealer is the practical choice. It seals portions of protein, stocks, sauces and prepped vegetables in the same machine, and the lower bag cost adds up quickly when you seal dozens of bags a day.

External sealers still make sense for a small café sealing dry goods, a food truck with little counter space, a caterer who needs something portable, or as a backup for occasional jobs. They are also a reasonable first step for a kitchen testing whether vacuum packing fits its workflow.

Butcher shops, commissaries and production kitchens packing all day usually move to floor-standing or double-chamber machines, where one chamber is loaded while the other runs its cycle.

Sous vide, marinating and compression

Chamber sealers are the standard tool for sous vide cooking in restaurants because they seal liquids, oils and marinades cleanly and produce tight, consistent packs that heat evenly in a water bath. Use bags rated for cooking at the temperatures and times you plan to use; not every vacuum bag is designed for extended cooking.

Deep vacuum has other uses. Compressing fruit such as watermelon or pineapple in a chamber changes its texture and colour, and some kitchens use vacuum to help marinades and brines work into thin cuts. Vacuum tumblers go further, turning meat in a drum under vacuum to distribute marinade or brine through larger batches.

Liquids boil at a much lower temperature under deep vacuum, so hot or even room-temperature liquids can bubble up and spill into the chamber. Chill soups, sauces and marinades before sealing, and use a lower vacuum setting or a liquid-sensing mode if the machine has one.

What to compare on a chamber sealer

Pump capacity is commonly given in cubic metres per hour. A larger pump empties the chamber faster, which matters when you seal many bags in a row, but it adds cost, weight and noise. Match it to the number of cycles you run in a busy session rather than buying the largest available.

• Pump type: oil-lubricated rotary vane pumps are the commercial standard; dry pumps need no oil changes and appear mostly on smaller machines.
• Seal bar length: sets the widest bag you can seal. Machines with two bars, or bars on two sides, seal more bags per cycle.
• Chamber size and depth: set the largest and tallest product. Measure your biggest roasts and containers.
• Controls: sensor-controlled machines stop at a set vacuum level for repeatable results; time-controlled machines run for a set period. Presets help when several staff use the machine.
• Soft air: lets air back in gradually so sharp or delicate products are not crushed and bags are not punctured.
• Gas flush: some models replace air with a protective gas, such as nitrogen, for crushable or delicate products; it needs a gas supply and training.
• Double or cut-off seal: a second seal line adds security, and a cut-off seal trims the excess bag.

Bags and pouches

Bag choice affects seal quality, cost and food safety. Chamber pouches are smooth and made in many sizes and thicknesses. Thicker bags resist punctures from bones and shells, and bone guards add protection for bone-in cuts. Cook-in bags are made to withstand the temperatures and times of sous vide and reheating.

External sealers need embossed or channelled bags or rolls. Rolls let you cut bags to length, which reduces waste on odd-sized products. Whatever the type, match the bag width to the seal bar, leave enough empty bag at the top for a clean seal, and keep the sealing area dry and free of grease.

Shrink bags, passed through a hot water tank or heat tunnel after sealing, tighten around meat and cheese for retail presentation. They are a separate system worth considering if you sell packed product at a counter.

Maintenance and food safety

Many performance complaints about chamber sealers trace back to the pump. Oil pumps need their oil changed on the manufacturer's schedule, and many machines have a conditioning or drying cycle that runs the pump warm to drive out moisture drawn in from wet products. Run it as the manual recommends, especially if you seal liquids often.

Clean the chamber after each session, wipe the seal bar and the pad opposite it, and replace the seal bar's heat-resistant tape and the silicone strip when seals start to fail or show gaps. Inspect the lid gasket for cracks, because a worn gasket slows the vacuum. External sealers need their drip tray emptied and the seal area kept clean.

Vacuum packing slows spoilage but does not make food shelf-stable. Removing oxygen can favour bacteria that grow without it, including the one that causes botulism, so packed food still needs refrigeration or freezing and a clear use-by date. Many Canadian health units expect a written food safety plan before a restaurant vacuum packs food for storage or cooks sous vide; ask your local public health unit what they require.

New equipment sold by Norpex carries the manufacturer's warranty, passed through in full. Keep the model number, serial number, install date and order number so Norpex can open a claim with the manufacturer. Floor-standing machines ship by freight and are not returnable once delivered in good condition.

Common questions