HeatwaveReady

Cooling gear reviews that tell you the whole truth — including who shouldn't buy.

We do the homework — specs verified on manufacturer pages, patterns from hundreds of owner reviews, prices with dates on them. Then you decide.

  • Specs verified at the source
  • Prices stamped with a date
  • Honest about the downsides
El Niño Advisory — Niño-3.4 at +2.6 °C · 56 active US heat & cold alerts (2026-09-02) · see the live map

Size it before you buy — three working calculators

Drag a slider, answer a question, get your number — the same cited math that runs our guides: ENERGY STAR for air conditioners, the US DOE formula for evaporative coolers, the National Weather Service for heat index.

What size air conditioner?

Answer a couple of plain questions and we’ll size it with ENERGY STAR’s official table and adjustment rules — then point you to the unit here that fits. Nothing invented; open “show me how” for the full math.

Where this number comes from

A sizing guide built from ENERGY STAR’s published table, not a full Manual-J load calculation. For odd rooms (lots of glass, top floor, extreme climates) an HVAC pro’s load calc is worth it.

Evaporative cooler: how many CFM?

Evaporative (“swamp”) coolers are rated in CFM airflow, not BTU. This uses the US Department of Energy’s formula — CFM = (volume × air changes per hour) ÷ 60 — then points you to a unit that meets it, if your air is dry enough.

Where this number comes from

Formula, the 20–40 ACH range and the wet-bulb ≤70 °F effectiveness threshold are the US DOE Building America Solution Center (PNNL)’s own — validated against its Salt Lake City worked example (16,000 cu ft × 20 ACH ÷ 60 = 5,333 CFM).

Heat index & humidity check

Enter your air temperature and humidity — or pull the latest reading from your nearest US National Weather Service station — to see the “feels-like” heat index, the NWS caution level, and whether an evaporative cooler will actually help at your humidity.

Where this number comes from

Heat index uses the National Weather Service Rothfusz regression. Live readings come from api.weather.gov (US only, public domain) and stay in your browser — we don’t store your location. Not medical advice.

Live US extreme-heat warning map

Every active National Weather Service extreme heat warning, heat advisory and cold alert, plus significant open events from NASA's EONET — fetched live from the official sources the moment you open the page. Click anything for its source. An alert on this map is not "caused by" El Niño; El Niño shifts a season's odds, and any tracker claiming otherwise is overclaiming.

Map data © OpenStreetMap contributors · Tiles by OpenFreeMap · Alerts: NWS/NOAA · Events: NASA EONET · ENSO: NOAA CPC · Sea-surface imagery: NASA GIBS

Want the full picture — ONI value, advisory status, the odds of a very strong event, and what El Niño does and does not mean for your weather? Open the El Niño tracker.

Start with your problem, not a product

Three of the trickiest cooling situations — each with its guide and its own calculator. Answer one question, get an honest fit (or an honest "nothing we cover fits").

No window? No hose? Cooling a room without a standard window What actually works, what's physics-defying marketing, and the honest decision tree. Read the guide Size it: BTU calculator
Sliding or casement window ACs that fit vertical windows Fit-first guide: measure, then buy. Units and vent kits that actually fit tall narrow openings. Read the guide Measure & size your room
Quiet air, small footprint Bladeless & quiet tower fans What "bladeless" really means, decibel numbers you can compare, and the honest DREO vs Dyson math. Read the guide Pick your fan in 30 seconds

Desert-dry air? Size an evaporative cooler (DOE formula) · No mains power? Battery-run AC for tents, vans and outages · Want one guided flow for everything? Use the all-in-one finder.

Why trust a site you found five minutes ago?

Fair question. Three answers: every spec we print links to the manufacturer's own page; every price carries the date we saw it; and every recommendation includes the case against buying it. When we haven't physically tested a unit, the review says so — our method is documented, and our funding is disclosed.

Data-driven tools, now available: a heat-index checker that answers "will an evaporative cooler even work at my humidity?" using your local NWS numbers, plus an El Niño tracker showing the latest official NOAA figures, updated monthly, for the 2026–27 season. Not sure what to buy? Start with the cooling gear guides.