H2S PLA cooling — feature request for active chamber cooling

Bambu Lab H2 Series Bambu Lab H2S
1

Hi Bambu team and community,

I got an H2S with AMS 2 Pro for small-business production work and ran into an issue I wanted to raise: the H2S chamber runs too warm for optimal PLA printing, with no built-in way to actively cool it.
The issue: During PLA prints, my chamber sits around 32°C with the default exhaust fan running. This degrades overhang quality because the part cooling fan recirculates warm air onto fresh extrusions. PLA softens well below 60°C, so 32°C ambient meaningfully reduces cooling on thin overhanging features.

Why this matters:
The H2S is marketed as versatile for both engineering filaments (which want heat) and PLA (which wants cool). But the design biases toward engineering use. For PLA production work, current options are:

-Crack the door open — defeats the enclosure, loses noise damping, releases fumes
-Aftermarket mods — voids warranty, no official solution
-Accept degraded overhangs — not acceptable for client work

Feature request:
Please add active chamber cooling to the H2 series, as either:
-Firmware that more aggressively manages exhaust and intake vents for low-temp filaments
-An official accessory (intake fan module, chamber cooler) using existing expansion ports
-A hardware revision with active cooling comparable to the X1

Questions:

  1. Are there planned firmware updates to improve low-temp filament handling on H2S?
    2.Are any cooling accessories planned for the H2 series?
  2. there an officially supported workaround for high-ambient environments? (my garage and entire house exceeds 40°C in summer :sob:)

What I’ve tried:
-Nozzle temp lowered to 205°C via temp tower
Part and auxiliary cooling fans maxed
-Bed temp reduced to cut radiant heat
-All fans verified running at expected speeds

These help but don’t solve the issue. The H2S is an excellent machine — PLA cooling support would make it significantly better for production use relying on standard filaments.

2

If you already tried maxing out all the fans, then what would you expect from a firmware update?

In its current design, the temperature will never get below ambient temperatures.

Reducing the ambient temperature is the only solution, if you ask me.

My chamber also gets around 30-32C during printing of PLA and PETG but don’t cause any issues here.

I have not heard of any active cooling to come for the H2 series.

3

That’s good you don’t get any nasty overhangs. What pla /pla plus filiment do you use?

4

I am using Bambu PLA Basic and Matte.

5

You can specify the chamber temp within the filament profile settings. By default it’s set to “0” for PLA, which basically disables temp control from my knowledge.

If you set it to say 30c, it should regulate the exhaust fan speed to keep the temp you have specified. At least it does during my testing.

6

So you’ve tried maxing out the fans and you’re still getting poor overhangs and higher chamber temps? This leads me to think your ambient air temperature is too high.

My H2S keeps the chamber temp around 32-33°c for pla by automatically adjusting the exhaust fan as needed.

7

According to official specifications, the H2D supports:

  • PLA

  • PLA-CF

  • PETG

  • PETG-CF

  • TPU

  • PVA

  • PA (limited support for PA/PA-CF)

Most of these materials, especially PLA, PETG, and TPU, do not benefit from active chamber cooling at standard ambient temperatures and actually suffer from it.

Curious what the difference would be , although this github post is concerned with the H2d , could it be a reason the H2s relies on venting either through the exhaust fan or the top vent , as im pretty sure both ways can help keep a temp constant

There is also this from the latest firware update

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