Methodology

This is the page where we show our working. It’s less fun than the rest of the site and considerably more important: Aircon Wars’s entire job is telling you which portable air conditioners are actually in stock, and that claim is only worth anything if you know where the numbers come from and how fresh they are. So here’s the full picture, estimates and all, with no hand-waving.

Where the data comes from

We combine two sources. The first is Awin product feeds: structured catalogue files that participating UK retailers publish, listing each product’s price, availability flag and stock quantity. We download and re-process these feeds roughly every four hours. The second is the eBay Browse API, which we query for matching items sold on eBay UK and which hands back a near-real-time availability estimate.

The two sources don’t quite speak the same language, so we translate everything into one consistent stock status (in stock, limited stock, out of stock, pre-order or backorder) and store every price in pence so nothing goes astray to a rounding error. That tidying-up is what lets us put a feed-based retailer and an eBay listing next to each other and rank them fairly, rather than comparing apples to slightly different apples.

How fresh is “live”?

Fair question, since we keep using the word. Awin feed data is at most about four hours old, and usually fresher than that. eBay figures are closer to real time but are still a snapshot from the moment we last asked. So every listing on the site wears a last-updated timestamp on its sleeve, so you can see exactly how recent its information is instead of taking our word for it.

What “limited” and “estimate” actually mean

Limited stock means the source is flashing a low-availability signal, often just a handful of units left. Read it as a polite nudge to get a move on, not a precise headcount. Estimatemeans the quantity isn’t a hard figure straight from the retailer’s till. eBay availability in particular is something eBay models rather than counts, so we flag those numbers as estimates and never dress them up as gospel. When we’re guessing, we’ll say so.

Why we always deep-link

No feed is perfect, and stock moves at an indecent pace during a heatwave. So every product links straight to the retailer’s own live page, the one source that knows the true, this-very-second price and availability. We’d far rather pack you off to check the real thing than have you put faith in a number that quietly went stale a couple of hours ago.

Where we fall short (we’d rather tell you)

• Feed lag.A retailer can sell out, change a price or restock between refreshes, and until our next pull we’ll be blissfully unaware.
• Estimated quantities. Some stock numbers, eBay especially, are estimates rather than exact counts. Trust the trend, not the decimal.
• Coverage.We only see retailers whose feeds we ingest, so we’re a strong slice of the market rather than every seller in the land.
• Spec gaps. When a feed leaves a field out (energy rating, noise level, coverage), we leave it blank rather than invent something plausible-looking.

The candour is deliberate. This category is under active scrutiny from the Competition and Markets Authority over stock and availability claims, and our take is that the honest move is to show the working rather than hide it. For who’s behind the site (and why we were sweaty enough to build it), see About Aircon Wars.