Suction, Not Slogans: Eight Checks for Range Hood Orders

🎛️ The Number on the Box Is Not the Number in the Room

A range hood is sold on a number - 900 m³/h, 60 cm, 65 dB - and almost every one of those numbers is measured under conditions your kitchen will never reproduce. That is not automatically fraud; it is a test condition you were never shown. The job of an inspection is to measure the same things the same way, on the same unit, and to compare like with like. Category checks of this kind sit inside our China pre-shipment inspection scope, and hoods are a good reminder that measurement beats a spec sheet. 🍳

🌬️ The Eight Checks

1. Airflow, measured rather than quoted. A handheld anemometer at the duct collar, then at the hood face, on each speed. We record the reading and the condition we took it in, because suction falls away fast with a filter in place and a short, kinked duct behind it. A hood rated at 900 m³/h that moves 500 out of the box is a hood that will not clear a wok.

2. The duct adapter and the backdraft flap. Does the adapter match the duct the customer will actually install? Does the flap close under its own weight or spring when the fan stops? A flap that hangs open is a hole in the wall when the hood is off, and it is one of the most common findings on this category.

3. Noise, on every usable speed. Measured at one metre, low and high. A third speed that only exists on the label is a customer-service ticket waiting to be written.

4. Filters and their clips. Baffle or mesh, seated, removable without a screwdriver, no sharp burrs on the cut edges, and clips that hold a loaded filter without cracking. Ask what happens to the filter at 60°C in a dishwasher - that is where a cheap plastic clip fails.

5. Speeds that are actually different. Three positions on the switch and three measurable airflow steps. Occasionally the third step is wired but never connected, which is invisible in a photo and obvious on an anemometer.

6. Lighting and controls. Switch and touch-panel cycles, light colour consistency, no flicker, no labelling in a language your market will not accept, and a control panel that does not register a press through a slightly damp finger.

7. Stainless grade and finish. Panel grade against the PO, brushed grain direction consistent across units, no burrs on folded edges, no tool marks on the visible face, and a grease tray that is deep enough to be useful rather than decorative.

8. Mounting hardware and packing. Bracket gauge, wall plugs sized for the load, chimney or extension pieces present and matching the carton's stated dimensions, corner protection on a long, thin product, and the FNSKU label where it belongs.

📐 Sampling: What We Pull, and How Much

A hood is a large, expensive unit, so sampling matters more than it does on a carton of small parts. The plan below is the standard AQL 2.5, general level II schedule we work to unless the PO says otherwise:

Visual defects are counted against that sample. Performance readings - airflow, noise, flap behaviour, speed steps - are taken across the sample and compared unit to unit, because one quiet number tells you very little on its own.

💨 What 1,800 Hoods Looked Like on the Bench

A buyer ordered 1,800 wall-mounted 60 cm hoods at FOB $52.40 - about $94,320. On a 125-unit sample our inspector found 13 hoods moving 470-520 m³/h against the 900 m³/h printed on the carton; 11 with a backdraft flap that stayed open and sealed nothing; 9 where the visible front panel would not hold a magnet, suggesting 430-grade steel where the PO called for 304; 8 with a third speed that was wired but never connected; 7 with loose or cracked filter clips; and 6 cartons shipped without corner protection. 🔌

Nothing on that list is visible in a product photo. All of it is measurable in an afternoon. The factory replaced the flaps, connected the third speed, re-printed the rating artwork down to the airflow the unit actually delivers, and re-packed the cartons with corner pads. Re-inspection of 80 units came back at a single unit - 1.25%, inside the limit. The intervention cost two man-days at $169, $338, against a container of hoods that would have generated complaints about suction on every single review.

🔍 The Honest Boundary

What we do: measure airflow with an anemometer, listen at one metre, actuate the flap, run the speeds, compare panel grade against the PO, inspect edges and finishes, count the hardware, and photograph the loading of the cartons.

What we do not do: we do not own a laboratory flow hood, so our airflow figure is an indicative field reading rather than an accredited test result. We do not certify UL, ETL, CE or any other approval, and we cannot confirm that a certificate was issued by an accredited body - that requires the certificate and the laboratory behind it. If a supplier's paperwork is the whole story, our report is the cross-check, not the replacement.

📝 Four Lines for the PO

1. Minimum measured airflow at the duct collar, with the filter fitted, and the rating on the artwork no higher than what the units actually deliver.

2. Backdraft flap must close under its own spring or weight; third speed must be connected and measurably different from the second.

3. Panel grade named for each visible surface, not just "stainless steel".

4. Corner protection on every carton, hardware kit counted, FNSKU placement in the packaging drawing.

Write those four and the inspection stops being a lottery. CloudSpects has run 2,000+ inspections with reports typically returned within 24 hours - check pricing from $169 a man-day, run the numbers on the AQL calculator, or get in touch before your hood order ships. 🚀

❓ FAQs

Why is measured airflow so far below the rated figure?

Because the number on the box was measured under conditions your kitchen does not reproduce: a straight, unrestricted duct, a clean filter, a specific static pressure and often a motor tested on a bench rather than in a housing. We measure at the duct collar and at the hood face with an anemometer and report what we measured, alongside the condition we measured it in.

What is a backdraft flap supposed to do?

It closes when the fan stops so outside air, insects and odour do not come back down the duct. If the flap hangs open, or the hinge has no spring or weight, the hood has no seal when it is off. We lift and release it and watch what it does.

Does stainless steel grade actually matter on a hood?

On the visible panel it matters for how the surface ages. A 430-grade front panel and a 304-grade front panel look similar under factory light and behave differently in a kitchen with steam and grease. We check the panel against the PO, look at an uncoated cut edge, and note that a magnet is not a reliable test.

How do you sample a hood order?

With the AQL plan written into the PO - typically AQL 2.5 at general level II - and with functional testing run above the sample size, because airflow, noise and flap behaviour are measurements rather than visual checks. Visual defects are counted against the sample; performance readings are compared across units.

Can you certify a hood for my market?

No. We inspect and measure, and we compare the nameplate, the carton and the supplier's documents for consistency. We do not certify UL, ETL, CE or any other approval, and we cannot verify the accreditation of a certification body. For that you need the certificate and the issuing laboratory.