NADIR vs Open/Shut
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
NADIR
This app helps you optimize your home's temperature by comparing indoor and outdoor conditions hour by hour. It provides precise recommendations on when to open and close windows for natural cooling without air conditioning.
- Hourly indoor/outdoor temperature comparison
- Daily recommended window opening times
- 30-hour projected temperature graph
- Open/close window alerts
- Home thermal physics explanations
- Home screen widgets
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NADIR compare, heure par heure, la température chez vous à celle du dehors. L'app vous dit exactement quand ouvrir et quand fermer vos fenêtres pour rafraîchir votre logement sans climatisation. CE QUE VOUS POUVEZ FAIRE : • Renseigner votre ville (ou géolocalisation) et les caractéristiques de votre logement en 4 réglages simples • Consulter le verdict quotidien avec le créneau conseillé (ex: « Ouvrez de 22h à 07h ») • Voir le graphe température extérieure vs intérieure projeté sur 30 heures • Recevoir des alarmes au moment d'ouvrir et de fermer (notifications répétées à +3 et +6 min) • Comprendre la physique derrière les calculs et consulter les sources scientifiques • Ajouter des widgets à votre écran d'accueil pour suivre le créneau en continu POUR QUI ? Ceux qui n'ont pas d'autre choix que de rafraîchir la nuit. NADIR ne milite pas contre la climatisation, il aide celles et ceux qui veulent maîtriser leur consommation d'énergie. DONNÉES : Météo en temps réel (Open-Meteo), calculs physiques (modèle thermique 2 nœuds), zéro pub, zéro tracking. App iOS native (SwiftUI, iOS 17+). Créée par Solal Gendrin, conseiller métropolitain écologiste à la Métropole de Lyon.
Open/Shut
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Open or shut? During a heatwave, everyone answers this question with instinct, and instinct is wrong. We open the windows when the weather feels nice, while the air outside is hotter than inside. We let in air that feels dry, while it actually carries more water. Open/Shut ends the guessing. ONE GLANCE, ONE ANSWER A full-screen verdict, updated in real time: OPEN or SHUT, with the reason in one sentence. No charts to interpret, no thresholds to configure. PHYSICS THAT IS ACTUALLY RIGHT Relative humidity is misleading: hot afternoon air can show a low percentage while holding more water than your living room. Open/Shut compares absolute humidity, the grams of water per cubic metre, indoors and out. Airing never trades a cool room for a damp one. IT KNOWS YOUR HOME Describe your windows once: "garden side", "bedroom skylight". When the verdict is OPEN, the app crosses the wind direction with your façades and tells you which openings to use for cross-ventilation, in your own words. It also learns your building's thermal inertia and estimates the indoor temperature between your readings. IT PLANS AHEAD An hourly timeline shows the next favorable window over the coming hours, and a notification arrives at the exact moment conditions flip. Open at the right time, not when you happen to think about it. SUMMER AND WINTER In summer, flush out the heat as soon as the evening air turns cooler. In winter, air strategically to fight condensation and mould without throwing your heating out the window. PRIVATE BY DESIGN No account, no backend, no tracking. Your location is only used to fetch your local forecast. Free, with no subscription. Open/Shut. An open-and-shut case.
Screenshots
Verdict
NADIR and Open/Shut are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
| Parameter | NADIR | Open/Shut |
|---|---|---|
| Price | Free | Free |
| Positive reviews | 85.7% of reviews | — |
| Update frequency | — | Daily |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone | iPhone |
| Requires iOS | 17.0 | 16.4 — better |
| Further details — not scored | ||
| Size | 3 MB | 65 MB |
| Age rating | 4+ | 4+ |
| Developer | solal gendrin | Berenger.dev |
In-app purchases
NADIR
No in-app purchases
Open/Shut
No in-app purchases









