Portable Air Conditioners, Air Coolers and Fans
Summer 2020 has been a bruiser: Record temperatures, lockdown, self-isolation, quarantine and staying indoors as much as possible. Here on the south coast, my garden thermometer read 41C in August and my portable AC units were working overtime.
The warmer it gets the more uncomfortable it is, and the MET office is predicting another hot one for 2021 so here are our tips on keeping cool with advice on buying and using fans, air coolers and portable air conditioners.
- Use a Fan:
If you want the feeling of air blowing over you or you need to keep circulating air around a room. Skip to About Fans
- Use an Air Cooler:
If you want cool air for a short while and are not fussed about wet (humid) air, or need to humidify your room (e.g:- if you are in a dry climate). Skip to About Air coolers
- Use an Air Conditioner:
If you want to keep a room at a constant cool temperature, clean the air and are not fussed about dry air or need to dehumidify your room (e.g:- if you are in a wet climate). Skip to About Air Conditioners
A fan blows air around, it does not cool air down because the fan motor generates heat while working it actually heats the air up a little.
Your body naturally cools itself by sweating, as the moisture evaporates it takes heat away from your body
A fan cools your body down by blowing air over your skin causing sweat to evaporate more quickly.
Fans do not clean the air or change its moisture content if it's a hot humid day they blow hot wet air around. If it's a hot dusty day they blow hot dusty air around.
Fans are cheap to buy, they are useful for:
Freshening rooms by moving air around without the need for cooling, cleaning or changing the airs moisture content.
Venting rooms, dispersing odours or water vapour, a bathroom extraction fan is a good example of this.
This fan circulates air around a greenhouse
If you want to cool air then you need an air cooler or a portable air conditioning unit.
There are a huge variety of styles and sizes, from very small personal desk fans which drive air a single person to giant pedestal fans which push air through an entire room.
A small personal fan
Use a slowly rotating large diameter fan for circulating air around a room, a speedy smaller diameter fan will give a faster-directed air flow.
You can even buy pocket-sized battery driven fans like this one to keep you cool on the move.
Directed flow fans channel a stream of fast-moving air towards a particular spot. Oscillating fans swing from side to side blowing air towards every corner of a room. Take a look at a range of Fans on Amazon
Before choosing your fan, decide what it is you want it to do, then choose from those designed for that purpose.
Check the manufacturer's warranty and look at the customer reviews before you buy.
For a desk or pedestal fan, we recommend VonHaus, as they are reasonably priced, well built and have 2-year guarantees
Dyson Tower Fans
They are fans, very clever fans with a brilliant air purifying system, but they are not air coolers or air conditioning units. Like all fans, they push air around but do not physically cool it.
The Dysons clever design produces a very high airflow rate, cooling you down by evaporating sweat quickly. When it gets very hot and you've no more sweet to evaporate then like all other fans it will be blowing warm air around your space.
Air coolers also humidify (add moisture to) the air because the water evaporates as the air passes through the machine.
They will cool the room but only as long as the water in them is cold.
Pros: We've tested many of these appliances, the only positive thing we find with them is they do not dry out the air.
Cons: Noisy and inefficient, the cheaper models are unreliable and break down frequently.
Most of them leak, especially when moved, as they are full of water.
Reliable ones are expensive, cheap ones are not worth buying.
The average domestic user would be better off using a fan and a bowl of ice. As shown in our article 7 Cheap & Easy Ways To Keep Cool This Summer.
If you buy one: The bigger & more powerful the fan the greater the airflow as more cold air is pushed around quickly, the larger the reservoir the longer it will keep the room cool for.
Also look out for multiple speed settings, air coolers don't have thermostats so you control the cool air flow with the fan speed.
Unless you need to keep your air moist we would recommend buying a portable air conditioning unit instead.
If you need moist air and must have an air cooler we recommend the Honeywell CS10XE as the best of the domestic bunch, it outlasts and outperforms the others we have tested. See here for our full review.
Our recommended best buy is the top performing Honeywell CL48PM.
This is a commercial grade model that works efficiently year on year. It has a 48-litre tank and can be plumbed directly into the main water supply. It is one of the best-selling air coolers in the world, see our full review here. It is designed for function, not looks and it is very noisy.
An air cooler is a cheap substitute for an air conditioner, why not get a portable air conditioner instead?
These come in two types (if you want to know how they work look here)
Fixed air conditioning units:
They draw in air from outside cooling it using a heat exchanger set outside of the building before blowing it into the room. We don't review this type.
The vents for air flow are fixed in windows or walls.
Portable air conditioning units:
These are compact portable appliances which suck air from the room into the unit which contains a heat exchanger.
They draw heat out of the air and a fan then blows the cooled air back into the room. The hot air is exhausted out of a ducting hose which is usually hung out of a window. These are the type we review.
Air conditioning units purify and dehumidify (remove the moisture from ) air passing through them, filtering out dust and blowing out cool, clean, dry air.
They all come with thermostatic controls to keep the room at a constant temperature and, like heaters, there are a range of extra options you can have depending on your needs.
Air conditioners were originally designed to remove moisture from the air and will dry out air in the room, they also need an external vent to get rid of waste heat (with a portable air conditioner a flexible ducting hose is used).
For general domestic use, we recommend portable units as they can be moved from room to room, during heatwaves you can use yours in the lounge during the day and in the bedroom on those hot sultry nights.
During winter they can be used as dehumidifiers to remove damp from the air, preventing mould, mildew and condensation problems.
We also review a model with a heating function which you can use for all year round climate control. The Trotec 4-in-1
Choosing a portable air conditioner
A too small unit will burn excess energy as it will overwork to keep your room cool, a too large unit will keep switching on and off too quickly, either way, they will cost you more to run than the right sized air conditioner for your space.
In the UK Air conditioners are usually rated in British Thermal Units (BTUs) 1 kW = 3,400 BTUs
Roughly calculated you will need about 30 watts (115 BTUs) for each cubic meter ( m3 ) of space.
We advise buying an air conditioner with a minimum output 7000 BTUs this is the minimum required to cool a small room (40m3) on a hot day.
Larger rooms up to 60m3 need around 10,000 BTUs and open plan rooms, lofts and office spaces up to 90m3 need at least 15000 BTUs.
Choose the right size for your room, then select the extra controls for your needs (remote control, timer etc...)
To see other options please visit our award-winning air conditioning expert partners at Airconcentre
Tip: If you have issues with dry air then a bowl of water placed across the room from your air conditioner and topped up regularly will keep the air moist.
Our Recommended Portable air conditioners:
Our best buy recommended portable Air Conditioner is The TROTEC PAC 2000 E Portable Air Conditioner. These are great units and such good value that they sell out quickly.
If you've missed out then our best selling Igenix IG9901 3-in-1 Portable Air Conditioner. Would be our next choice. Both are in stock and on sale with massive discounts now.
Air conditioning units were originally designed as dehumidifiers to remove moisture from the air to keep paper stock at a publishing company dry during humid summers.
Because cold air holds less moisture than warm air the warm moist air was cooled by blowing it across cold pipes. As the air cooled water condensed out of the air drying it. Cooling the air was a fortunate side effect of the process.
An air conditioner does this by refrigerating the air using a technique known as phase conversion, this is a law of physics which states that when a liquid changes to a gas it absorbs heat, so air conditioners use a closed system of coils containing chemicals called refrigerants which constantly change from gas to liquid and back again.
When the fan blows air over one set of coils (evaporator coils) the refrigerant changes from a liquid to a gas absorbing he
at from the air, this cold air is channelled into the room cooling it.
The gas is then pumped into a compressor which pressurizes it causing it to turn back into liquid. This now warm liquid flows through a second set of coils (condenser coils) and a second fan blows over these coils removing the warm air (which is channelled outside) and cooling the liquid, which is then routed back to the evaporator coils and the process starts all over again.
With portable air conditioning units, the hot air is vented out via a ducted hose which can be hung out of a window or attached to a wall vent, similar to the way a tumble dryer is vented.
For more info on buying and using air conditioners see the Air conditioner buying guide at aircon centre