Signs & diagnostics
Droplets gathering on the underside of a canopy mean the warm, moist air it should be carrying away is lingering long enough to condense. That is a humidity and airflow signal: the extract is not moving steam out fast enough, and grease is usually the reason it slowed down.
The short answer
Droplets gathering on the underside of a canopy mean the warm, moist air it should be carrying away is lingering long enough to condense. That is a humidity and airflow signal: the extract is not moving steam out fast enough, and grease is usually the reason it slowed down.
The detail
Cooking throws off steam as well as heat and grease, and the canopy is meant to draw all three away together. When it holds its design airflow, the moist air leaves before it can cool and condense. When airflow falls, that warm, humid air dwells under the canopy, hits the cooler metal and turns to droplets - the condensation you can see.
Grease is the usual brake on the airflow. It loads the baffle filters and duct, raises resistance, and the fan moves less air, so the steam that used to be carried off now hangs around long enough to condense. A canopy that stays dry in a healthy system starts weeping once the extract falls behind.
The moisture makes other problems worse. A humid exhaust degrades odour control, because activated carbon preferentially adsorbs water and spends its capacity on moisture instead of smell. And dripping condensate can carry grease with it back onto the line, mixing a hygiene issue into what looked like a simple airflow one.
Make-up air ties in too. If replacement air is short and the room runs negative, air movement under the canopy is disturbed and less effective at clearing steam, so condensation can appear even where the extract path is only moderately loaded. Balanced make-up air at around 85 percent of the extract rate keeps the moisture moving.
What it means for you
Condensation is an airflow symptom, so the fix is to restore the airflow. Cleaning the filters, plenum and duct back to TR19 Grease condition lets the fan move its design volume again, so steam is carried away before it can cool and drip, and the canopy stays dry through service.
It also lifts the knock-on effects: better airflow means lower humidity, which protects odour control and stops condensate carrying grease back onto surfaces. If dripping persists after a verified clean, inadequate make-up air or a canopy and duct design issue is the next thing to check.
Phoenix Duct Clean restores the airflow that moves steam out of the kitchen and measures the result, so condensation under the canopy is cleared at its cause rather than wiped away between services.
The service behind the guide
Sibling guides
Five signs it needs cleaning now · Grease dripping from the canopy · Setting a fit-out cleaning baseline
Questions
Because warm, moist cooking air is lingering under the canopy instead of being drawn away, so it cools on the metal and condenses. That points to reduced airflow - the extract is not moving steam out fast enough - and grease loading the filters and duct is the usual cause.
It can become one. Dripping condensate can pick up grease and carry it back onto the cooking line, and the damp, humid conditions are not ideal near food. Clearing the airflow that removes the moisture addresses the hygiene angle as well as the comfort one.
Yes. A humid exhaust degrades odour control because activated carbon preferentially adsorbs water, using up capacity that should be removing smell. So a steamy, condensing system often smells as well, and restoring airflow helps both.
If reduced airflow from grease is the cause, restoring the system to TR19 condition lets the fan move its design volume again, carrying steam away before it condenses. If dripping persists after a verified clean, make-up air or a canopy and duct design issue needs attention.
It can contribute. If replacement air is below around 85 percent of the extract rate the room runs negative and air movement under the canopy is disturbed, so steam clears less effectively and can condense even when the extract path is only moderately loaded.
Phoenix Duct Clean · by the numbers
It is a moisture-and-airflow signal. Book a clean to move the steam out before it drips.