Understand the fundamentals
Air must travel through the intended path
Fans pull or push air through a miner in the direction it was designed for. Cooler air enters at the intake, also called the inlet. It picks up heat from the cooling surfaces, such as heatsinks, and leaves as warm exhaust. The miner must face the right way, and hot air must be kept apart from cool air. This helps the exhaust leave instead of flowing back into the intake.
Blockages, clogged filters, built-up dust and debris, or changes to the facility airflow can all reduce useful flow. The effect can differ from place to place in a rack or container. One reading of the room temperature can miss a single miner that is pulling in hot air.
See how it works
Containment controls where the air goes
Containment means the barriers, such as walls, doors or curtains, that keep cool supply air apart from warm exhaust air. Gaps, open doors or unsealed openings in the containment can let the two mix. Two problems can follow. Recirculation is when warm exhaust flows back into an intake. Bypass is when cool air goes around the equipment instead of through it, so it is wasted.
Do not add homemade covers or close openings yourself. Any change must follow the approved design. A change that makes one spot feel cooler can cut airflow somewhere else or upset the air pressure balance. Instead, tell facilities staff where you saw the problem and what pattern you noticed. They need this to check the shared system.
Visual explanation
Useful flow and hot-air recirculation
- Intended path
- Cooler inlet air passes through the miner, collects heat and leaves toward the exhaust area.
- Recirculation path
- Some heated exhaust returns to an inlet, raising the temperature of the air supplied to the miner.
- Bypass
- Cool air goes around the equipment instead of through it, so it is wasted.
The arrows show a simple example, not the direction every miner must face. Any change to containment must follow the approved facility design.
Connect it to the field
Example: the end of a row runs hotter
Suppose a row holds identical miners running at similar loads. The miners at the end of the row show higher inlet temperatures than those in the middle. It is unlikely that all the end-row fans failed on their own at the same time. So look first at local airflow and at exhaust flowing back to the intakes. This is still only a hypothesis, an idea to test, until someone investigates.
From a safe position, note which way the miners face, their intake readings and where the hot ones sit. Compare only the same models running the same operating profile. Also record any recent maintenance or changes to doors, filters or containment. The airflow can change even when nothing on the miners has changed.
Terms used in this lesson
- Inlet
- Where cooling air enters a particular machine.
- Outlet
- Where warm exhaust air leaves after collecting heat.
- Recirculation
- Heated exhaust finding its way back into cooling inlets.
Optional references & further reading
Use current manufacturer instructions for the exact equipment and your site’s approved procedures. Course levels do not grant task authorization.