3D Printer Enclosures and Air Filters: What They Do and Cost

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Many entry-level printers are open-frame. For PLA and PETG that is not a problem. As soon as you want to print ABS or ASA, though, or the printer stands in a living space, or noise and dust bother you, the question of an enclosure comes up. This article explains what an enclosure does, which variants exist and when an air filter makes sense in addition.

What an enclosure is good for

• Heat in the build chamber: ABS and ASA shrink strongly as they cool. An enclosure keeps the heat of the print bed in the build chamber and so reduces warping and cracks between the layers.
• No draughts: even an open window or an air conditioner is enough to make corners lift off the bed.
• Less noise: fans and stepper motors are dampened, but not silenced. How much it helps depends heavily on material and how well it seals.
• Less dust: on axes, print plate and filament.
• Containing emissions: particles and gases initially stay in the enclosure. Without a filter or exhaust, though, they escape at the latest when you open it. An enclosure alone therefore does not make the air cleaner.
• Protection: children and pets cannot as easily reach into hot or moving parts.

What particles and gases are produced during printing and how to ventilate properly is covered in detail under 3D printing safety.

Variants at a glance

A Lack side table costs around €10 at IKEA. For a typical enclosure you stack two tables and add side walls made of acrylic or polycarbonate panels. Panel prices depend heavily on size and material.

If you print a lot of ABS, ASA or nylon, you should also take a look at enclosed printers. A retrofitted enclosure with a filter quickly reaches the price difference to an enclosed machine.

What to look for in an enclosure

Electronics and power supply

It gets warm inside the enclosure, quickly 40 °C and more with ABS. The mainboard, stepper drivers and power supply are not always designed for this. Many enclosure build plans therefore move the power supply and electronics outside. If that is not possible with your printer, ensure ventilation for the electronics and keep an eye on the temperature with a simple thermometer. The filament extruder and plastic parts on the printer itself can also soften at high chamber temperatures, especially if they are printed in PLA.

PLA in an enclosed chamber

PLA does not like heat. If the chamber gets too warm, the filament softens above the nozzle and the extruder clogs. The Prusa Knowledge Base names a room temperature above 35 °C, or above 30 °C with some filaments, as a common cause of this so-called heat creep. A fully closed, unventilated enclosure is very likely to be a problem for PLA. For PLA and usually PETG as well, therefore open the door or lid or fit a fan. More under Clogged nozzle.

Fire protection

An enclosure shuts the printer in, including in the event of a fire. Therefore:

• Prefer non-combustible or flame-retardant materials, for example metal, glass or aluminium composite panels. Acrylic burns, polycarbonate is more flame-retardant. Wood and wood-based materials, as in Lack tables, are combustible.
• With fabric tents, check the manufacturer’s heat resistance information and do not let them rest directly against the hotend.
• Do not store filament spools, papers or cleaning agents in the enclosure.
• Smoke detector above or next to the enclosure, not just somewhere in the room.
• Design cable pass-throughs so that nothing chafes.

Air filters: what they can and cannot do

Filter modules for retrofitting into enclosures are available, often as a combination of two stages.

HEPA against particles

HEPA filters retain solid particles. Filters of class H13 according to EN 1822 capture at least 99.95 % of particles in the most difficult size to filter. That makes them the right choice against the ultrafine particles produced during printing. Make sure the class is stated precisely. Wordings such as “HEPA-type” or “HEPA-like” are not a protected class.

Activated carbon against gases and odours

Gases such as styrene from ABS simply pass through a HEPA filter. That is what activated carbon is for. It binds some of the volatile organic compounds, but not all equally well, and at some point it becomes saturated. Then it lets more through again. How long a filter lasts is stated by the manufacturer. For a printer manufacturer’s filter module, for example, at least 600 operating hours are stated. More carbon and a slower airflow generally work better than a thin carbon fleece.

Recirculating or exhausting outside

Exhausting outside is the most effective solution for ABS, ASA and nylon. Recirculating filters are a good compromise if no window is within reach. Neither replaces a ventilated room. After printing, wait a few minutes before you open the enclosure so that the filter can keep working.

Filter prices

• Retrofit filter modules with HEPA and activated carbon: about €50 to €150
• Replacement filters: about €15 to €50, depending on the module
• Exhaust with inline fan and hose: about €30 to €80, depending on the fan

Include the replacement filters in the running costs.

Decided quickly

• Only PLA and PETG: an enclosure is not necessary. If you want one, then for dust or noise, and with the door open or a fan.
• Occasional ABS or ASA: a fabric tent or Lack enclosure plus ventilation is often enough for small parts.
• Regular ABS, ASA or nylon: sturdy enclosure, electronics outside, exhaust outside or a filter with HEPA and activated carbon.

Continue with: Printing ABS.