Glossary

Unit of thermal power still widely used to indicate the cooling capacity of an air conditioner, especially on portable models. The higher the BTU/h figure, the more the unit can theoretically cool a large or heavily sun-exposed room. Cooling capacity is also increasingly expressed in kilowatts (1 BTU/h is about 0.293 W).

An air conditioner's cooling capacity, expressed in kilowatts (kW) rather than BTU/h on the most recent spec sheets. As a rule of thumb, allow roughly 100 W of cooling capacity per m² of room, assuming reasonable insulation.

A device that cools air by evaporating water held in a tank or a filter cartridge. Effective mainly in dry air, it stays noticeably less powerful than a real compressor-based air conditioner, but uses far less electricity.

An air conditioner made up of an indoor unit and an outdoor unit linked by a refrigerant line. More efficient and quieter than a portable model, but its installation requires a certified professional to handle the refrigerant.

The two blocks of a split air conditioner: the indoor unit distributes the treated air into the room, the outdoor unit houses the compressor and expels the heat it captures. They are linked by a refrigerant line fitted by a professional.

Technology that lets an air conditioner's compressor adjust its power continuously, rather than simply switching fully on or off. The result is a more stable temperature, quieter running, and generally better energy efficiency than a conventional compressor.

A function that automatically swivels a fan's head from side to side, to spread the airflow over a wide angle instead of concentrating it on a single spot.

An air conditioner you can move from room to room, which vents extracted hot air through a hose run out of a partly open window. Needs no installation or professional work, unlike a fixed split unit.

A setting that lowers a fan's or air conditioner's speed to reduce its noise level, usually at the cost of a lower airflow or cooling power. Designed for overnight use without disturbing sleep.

A propane-based refrigerant valued for its very low impact on global warming (GWP close to 3, against several thousand for older gases), but mildly flammable, which imposes strict safety limits on the quantity allowed per appliance. Increasingly used in recent air conditioners and compressor coolers.

The refrigerant that has become the standard on recent air conditioners, with a much lower impact on global warming than the older R410A, while staying non-flammable under normal household use. Handling it still remains reserved for a certified professional.

The substance that circulates inside an air conditioner's or a compressor cooler's circuit, absorbing heat as it evaporates then releasing it as it condenses. Handling it (charging, topping up, recovery) is strictly regulated and reserved for certified professionals.

An air conditioner able to reverse its refrigeration cycle to produce heat in winter instead of cooling, then working as an air-to-air heat pump. A single unit thus covers summer cooling and economical supplementary winter heating.

An electric cooler with no compressor or moving mechanical parts, and therefore completely silent. Less efficient than a compressor cooler, it maintains a more modest gap from ambient temperature.

A design feature that limits the vibrations a wine cooler's compressor transmits, which can disturb wine over the long run by speeding up certain chemical reactions in the liquid. A point worth watching mainly for storage spanning several years, less critical for short-term serving use.

How long an electric cooler or portable fridge can run on an auxiliary battery or power station before needing a recharge. Depends on the appliance's power draw (in Wh), the battery's capacity, and the outdoor temperature.

The continuous maintenance of a low temperature for a food product, from production through to consumption. Even a brief break in the cold chain encourages bacterial growth and shortens the food's safe shelf life.

An electric cooler fitted with a real compressor, just like a conventional fridge, able to reach sub-zero temperatures and stay effective even in high outdoor heat. The most efficient technology, but also the heaviest and most expensive.

A scale (from A to G since the 2021 EU labelling reform) indicating the electricity consumption of an appliance such as a fridge or a freezer. Since such an appliance runs 24/7 all year round, choosing a good energy class usually pays for itself within a few years through the savings made.

A freestanding wine cooler vents its heat from the sides and back, so it needs clear space around it to ventilate properly. A built-in cooler vents air only from the front, letting it sit inside an enclosed kitchen cabinet, provided the model is actually designed for that use.

A fridge with a separate built-in freezer compartment, most often in a 70/30 configuration (70% of the volume for the fridge, 30% for the freezer). The most complete solution for a main kitchen, as opposed to a standalone fridge or freezer.

Technology that circulates cold air in a way that prevents frost forming inside a freezer or the freezer compartment of a fridge-freezer, avoiding the need for regular manual defrosting.

A removable wooden or metal shelf that bottles rest on inside a wine cooler or a fridge. On wine coolers, sliding shelves make it easier to reach bottles at the back without having to move the ones in front.

A single-zone wine cooler keeps one uniform temperature throughout, suited to long-term storage of one type of wine. A dual-zone cooler splits the interior into two compartments at different temperatures, handy for storing reds and whites together, or for storing and serving at the right temperature at once.

A type of compressor used in some premium compressor coolers, designed to be insensitive to vibration, shocks and tilting. Especially valued in motorhomes, 4x4s and boats, where movement is constant.

The difference between the temperature reached inside an appliance and the ambient air temperature around it. A figure that reveals an electric cooler's real performance better than the minimum temperature alone, which depends heavily on test conditions.

An electric cooler that uses the Peltier effect (an electric current through two different materials creates a temperature difference) to cool, with no compressor or gas. Light and simple, but its gap from outdoor temperature stays limited, typically around 15 to 20°C below ambient.

Two freezer formats: an upright freezer opens via a front door and makes organising its contents easier (drawers, shelves), while a chest freezer opens from the top and keeps the cold in better, since cold air, being heavier, doesn't escape when opened.

A tinted glass door that filters ultraviolet rays, which can alter a wine's taste and speed up its ageing if exposed to light for too long. A feature worth prioritising on a wine cooler that sits in natural daylight.

A safety feature that automatically shuts off a misting system's water supply if it detects a leak or excess pressure, to prevent water damage during a long absence.

A misting system fitted with a pump that raises water pressure to several dozen bar, compared with plain tap pressure for a basic kit. That higher pressure produces a much finer mist, which evaporates before reaching the ground and cools the air without soaking the patio.

Spraying a fine cloud of water droplets which, as it evaporates on the skin or in the surrounding air, brings instant relief. Used on personal devices as well as on patio or pergola installations.

A portable device combining a classic fan with a water tank sprayed as a fine mist, for extra cooling outdoors (festivals, sport, gardening) compared with using a plain fan or a plain mister separately.

A small fitting pierced with a very fine hole, installed on a patio or pergola kit, that turns pressurised water into a fog of fine droplets rather than a jet. The hole's diameter determines how fine the resulting mist is.

A set of pipes and nozzles connected to a garden tap, installed on a patio, pergola or deck, which releases a curtain of fine droplets that cools a whole outdoor area rather than a single person.

Thermal water sprays (Avène, La Roche-Posay, Jonzac...) are enriched with trace elements and designed to soothe the skin as much as cool it, while a classic mineral water spray (Evian...) mainly aims for a simple cooling and hydrating effect, at a lower cost.

A function that automatically alternates misting phases with pause phases over an adjustable duration, rather than misting continuously. It cools a patio effectively without wasting water or oversaturating the air with moisture.

A metallised coating used inside some insulated bags to reflect heat rather than simply insulate against it, an alternative to PEVA that slightly improves thermal performance at the cost of slightly trickier care (not dishwasher-safe).

A closure system that automatically seals a mug's or bottle's opening as soon as the release button is let go, preventing any leak even if the container is on its side or shaken inside a bag. A practical alternative to a classic screw cap, especially for use in a car.

A claim indicating that a food container (box, insulated bag, bottle) contains no bisphenol A or phthalates, two families of chemicals suspected of migrating into food and controversial on health grounds. A common selection criterion for containers meant for repeated use.

How long an insulated container keeps a drink or food below (cold) or above (hot) a given temperature threshold, usually measured over 6, 12 or 24 hours depending on the manufacturer. A figure to compare with some caution, as testing protocols vary between brands.

A stainless steel alloy (18% chromium, 8% nickel) commonly used for quality insulated bottles, flasks and boxes, valued for its resistance to corrosion, its lack of any metallic taste transferred to food or drink, and its durability.

Describes a container (bottle, cooler, bag) designed to limit heat exchange with the outside, so it keeps a temperature, cold or hot, for a long time. Not to be confused with 'insulating', which refers to the material used to achieve this effect.

A soft, foldable container with insulated walls, lighter and less bulky once empty than a rigid cooler. Suited to short outings and carrying several meals or drinks, usually at the cost of lower thermal performance than a rigid cooler of the same volume.

A double-walled insulated lunchbox that keeps a meal hot or cold until it's time to eat, with no microwave or ice needed, handy for the office, school or a picnic.

A flexible plastic material used as the insulating lining in many insulated bags, marketed as an alternative to classic PVC because it contains no chlorine or controversial plasticisers. A frequent claim on product pages aimed at food use.

The construction technique behind an insulated bottle or mug: two metal walls separated by a vacuum, which sharply limits heat transfer by conduction and convection. This is what lets a bottle keep water cold, or a drink hot, for many hours.

A highly porous material fitted alongside a HEPA filter, which absorbs odours, smoke and volatile organic compounds (VOCs) that mechanical filtration alone can't catch. It wears out over time and gradually loses its absorption capacity, which is why it needs changing periodically.

A standardised rating (Clean Air Delivery Rate) that measures the volume of air an air purifier actually clears of particles, smoke or pollen, expressed in m³/h. Unlike a fan's plain airflow figure, CADR accounts for filtration efficiency and lets you objectively compare two units.

A dehumidifier that cools air over a cold coil to condense the moisture into liquid water, much like a fridge does. The most efficient technology in a heated room (above roughly 15°C), but it loses performance in a cold, unheated cellar or garage.

A function that lets you connect a hose to a dehumidifier's tank to drain the collected water continuously towards an outlet, instead of having to empty the tank by hand regularly. Handy for extended, unattended use in a cellar or utility room, for example.

A dehumidifier that passes air through an absorbent material (usually silica gel), then heats that material to release the moisture it captured. Less efficient than a compressor model in warm air, it stays effective even at low temperatures, which makes it a better fit for a cellar or garage.

A humidifier that passes an airflow through a water-soaked wick or disc, which evaporates naturally into the room with no visible mist. It self-regulates to some extent, since evaporation slows on its own as the surrounding air becomes more humid, at the cost of a slower rise in humidity than an ultrasonic model.

The amount of water a dehumidifier can pull from the air in a day under standardised test conditions (typically 30°C and 80% humidity), so the figure is always higher than what you'll actually see at home. Comparing this value between models is still useful, as long as you keep that lab-versus-real-life gap in mind.

A high-efficiency filter able to trap at least 99.95% of particles down to 0.3 microns for the H13 grade, the most common class on home air purifiers. It catches pollen, fine dust and much of airborne bacteria, but needs replacing regularly to keep its efficiency.

A sensor that measures the air's humidity level and lets a humidifier or dehumidifier automatically target and hold a set percentage, rather than running continuously. The equivalent of a thermostat, but for humidity rather than temperature.

A function that electrically charges particles suspended in the air so they clump together and settle to the ground faster, on top of filtration. Some models produce a small amount of ozone while running, worth checking in the spec sheet for anyone sensitive to it.

Airborne dust classified by diameter in micrometres: PM10 for particles smaller than 10 microns, PM2.5 for the finest ones, able to penetrate deep into the respiratory tract. Most purifiers include a sensor that measures this level in real time to automatically adjust their power.

The percentage of water vapour actually present in the air compared with the maximum it could hold at that temperature. Indoor comfort generally sits between 40 and 60%, below that the air is dry and irritates the airways, above it, mould and dust mites thrive.

A humidifier that vibrates a membrane at very high frequency to turn water into a fine cold mist, with no heating or boiling involved. Quiet and energy-efficient, it does need demineralised or filtered water in return, to avoid white mineral dust settling around the unit.

A family of chemical substances (paints, glues, cleaning products, new furniture...) that evaporate at room temperature and can degrade indoor air quality. An activated carbon filter is generally needed to catch them, since a HEPA filter alone only acts on solid particles.

An insulating sleeve kept in the freezer then slipped around a wine or champagne bottle to keep it cool at the table, without the dampness that comes with a classic ice bucket.

A small device, often wireless, that measures the actual temperature inside a fridge (ideally between 0 and 4°C) or a freezer (-18°C), more reliable than the sometimes-approximate display on some appliances.

A compact electric appliance that produces several kilos of ice cubes a day in just minutes, without going through the freezer's ice tray or waiting hours for it to freeze.

A pouch filled with a cooling gel, kept in the freezer then slipped into a cooler or insulated bag. Melts more slowly than a regular ice cube and leaves no meltwater behind once thawed, unlike loose ice cubes.

A sealed, hollow metal rod, kept in the freezer then inserted directly into a bottle's neck to cool the wine from inside without ever touching the liquid, so it never dilutes it the way an ice cube would.

The volume of air moved by a fan or air conditioner in one hour, expressed in cubic metres per hour. A higher airflow generally cools a larger room faster.

The unit of electrical current. For a 12V-powered appliance (an electric car cooler, for example), the amps it draws give a direct sense of how quickly it drains the vehicle's battery.

The unit of measurement for noise level. For a fan or an air conditioner, the lower the stated dB figure, the quieter the appliance. As a reference point, a normal conversation sits around 60 dB.

A unit of power equal to 1000 watts, commonly used to express an air conditioner's cooling capacity or a large appliance's electrical power, rather than the watt alone which suits smaller appliances like a fan better.

A unit of length equal to one thousandth of a millimetre, used to indicate an air purifier's filtration fineness (the size of particles it traps) or a misting nozzle's fineness (the size of the droplets it produces). The smaller the micron figure, the finer the filtration or the mist.

Energy-efficiency indicators for a reversible air conditioner, calculated over a whole season rather than at a single point in time: SEER for cooling mode, SCOP for heating mode. The higher these values, the less electricity the unit uses for the performance it delivers.

The storage volume actually available inside a cooler, fridge or freezer, often slightly lower than the stated gross volume once insulating walls and internal fittings are accounted for.

The unit of electrical power. An appliance's power draw (in watts) determines its impact on the electricity bill in use: a fan typically draws a few dozen watts, against several hundred to over a thousand for an air conditioner.

A unit of energy (not power) that indicates the amount of electricity consumed or stored over a given time, used to express a battery's or power station's capacity, and therefore the runtime it gives an appliance such as an electric cooler.

The service a manufacturer or retailer offers to handle complaints, repairs and exchanges after a product is purchased, especially during the manufacturer warranty period.

A unique numeric code (often shown as a barcode) that precisely identifies a product and its manufacturer, useful for tracking down an exact reference or checking you're comparing the same model across different retailers.

The manufacturer's commitment to repair or replace a faulty appliance for a set period after purchase, generally 2 years in Europe, sometimes longer on certain premium appliances (air conditioners, compressor coolers). Distinct from statutory conformity guarantees, which apply regardless.

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The document provided by the manufacturer explaining an appliance's installation, settings and maintenance. Often also available as a downloadable PDF on the manufacturer's website if the paper copy is lost.