After a sweltering week with sleepless nights in the sticky heat and with summer still ahead of us, households across the country are asking if it is finally time to take the plunge and invest in air conditioning.

While an AC unit is common in most American homes – and even some in southern Europe – households in typically grey Britain stick to trusty desktop fans and old-fashioned open windows to keep themselves cool.

But with this May reaching record temperature highs, it could be a worthwhile purchase.

Any household willing to buy a unit, however, will need to have deep pockets. Unlike a basic household fan, these heavy-duty units don’t come cheap and can cost close to £10,000 in some cases.

Money Mail picks apart the four main types of systems you can purchase – and whether the costs are really worth it.

What are the different types of air conditioning – and which is right for me?

Wall-mounted units

The most common aircon unit that you’ve probably seen in a neighbour’s home or in a small shop is the wall-mounted unit.

It is also known as a split system and is among the most popular – it makes up around 80 per cent of work for Aria Toupchi, company director at London-based Debonair Cooling.

They look like large white rectangles with a vent or grate on the front.

It cools the air by passing air between an indoor and outdoor unit, connected by a pipe that is fed through the wall.

Air from the hot room is drawn into the wall-mounted unit indoors and travels over pipes filled with a cold refrigerant.

The air is cooled by the pipes and the excess heat is emitted through the outdoor unit, according to Midland Aircon. The cold air is then released into the room, cooling down the space.

It is possible to get a wall-mounted air conditioning system without an outdoor unit, which is beneficial for those that live in flats or listed buildings where changes to the exterior aren’t permitted.

These wall-mounted systems only cover one room, however, so you’ll need to pay for a unit and installation for each room you want to cool.

It will work well for families who only want to cool a particular space, perhaps a bedroom or living room.

You will need adequate wall space to be able to install these units.

Floor-standing systems

Floor mounted or standing systems work like a wall-mounted system, but the AC units are instead placed on the floor or low on a wall.

They also comprise of two units – an indoor and outdoor – but can be an eyesore as they will be more visible than a wall-mounted version high up.

These are great for homes with little overhead or wall space, says Mr Toupchi, and he commonly installs them in loft spaces. They are also good for sunrooms or areas with floor-to-ceiling windows.

Ducted systems

Families with a bigger budget or a large house with multiple rooms that need cooling could consider a ducted system, often called a central air conditioning system.

These are discreet systems that are recessed into the ceiling that use the same technology to cool the air as wall-mounted units.

They work with only one indoor unit but can still cool every room in your home without an unsightly air conditioning unit in each of them.

The unit pulls in the air, cools it and sends it to other rooms in the house by ducts in the ceilings and walls. This links to a vent in each room, where the cold air will flow from.

They are far less common than the wall mounted system, however, making up just 10 per cent of Debonair Cooling’s business.

That’s mainly due to their cost – they are far more expensive to install due to the amount of labour needed.

Plus, British homes aren’t ideal for this type of system as they need a large ceiling cavity or void.

Portable aircon

If you’re on a tighter budget and want something you can pop away in the attic when the summer months end, then a portable air conditioning unit may be for you.

These are small block units that you can plug in yourself and do not need to be installed.

They work like other air conditioning units – pulling in hot air, cooling it with a refrigerant, and sending the cold air back out into the room.

The unit will come with a ‘window kit’ that will allow you to vent the hot air to the outside via an exhaust hose.

The hose is placed into the back of the unit and connected to a cut out in a piece of plastic or fabric that is attached to the window.

You can move them from room to room, instead of installing a system in each one. However, they don’t cool as well as the permanent units. Plus, they are noisier than other options.

How expensive is air conditioning?

If you want an affordable way to cool your home, then air conditioning isn’t for you. The hit to your pocket will depend on the type of aircon you choose to install.

For the most common wall-mounted options, expect to pay anywhere from £620 to £890 for the equipment, but some £960 to £1,380 for installation, according to traders’ website Checkatrade. If you want an even more powerful unit, expect to pay more.

Mr Toupchi says his clients often pay between £2,000 to £3,000 for one of these systems, and that they take around a day to install each unit. So if you are buying two units for two rooms, allow two days.

Don’t attempt to install it yourself, as the law dictates that an F-Gas certified engineer must do so.

Floor standing units can be slightly more expensive than their wall-mounted counterparts, says Mr Toupchi, at around £2,500 to £3,500.

Ducted systems are even more costly, which is why they are typically only used in commercial properties such as hotels or affluent residential homes.

But Mr Toupchi says it can cost between £6,000 to £8,000 for one of these sleek systems. Other installers place the cost at around £8,000 to £12,000 for even a small home.

Installation times can be three to four days, as ducting needs to be installed to connect each room to the central AC unit.

A portable unit is the cheapest option at around £300 to £420, according to Checkatrade. Plus, it requires no professional installation.

Although price tags are high, having such a system already installed could soon add value to your house price when you sell.

Jo Lambert, of Mitsubishi Electric, says: ‘Air conditioning is still quite a new concept in the UK, so there isn’t a uniform measure to say how much value it could add to your home.

‘It is, however, becoming an increasingly attractive energy-efficient feature and increases appeal to buyers, especially as we continue to experience extreme swings of temperature throughout the year.

‘Modern air conditioning also has dual barrier coatings which help to remove dust, mould and pollen from rooms, which helps improve the indoor air quality and will also really benefit asthma sufferers.’

How much will it cost to run?

The costs don’t stop there. In addition to the unit and installation costs, you’ll also need to pay for the energy needed to cool the air.

While a pedestal fan costs just 84 pence a week to run, air conditioning units guzzle energy.

An average ‘built-in’ unit uses £42.43 worth of energy per week, according to calculations by comparison website Uswitch. For a portable system, it is £15.71 a week.

This assumes the cooling system is used for nine hours every day and the household does not have a fixed rate tariff and is charged according to Ofgem’s energy price cap.

Checkatrade estimates it will eat up between 20 to 60 pence per hour it is turned on.

Of course, the actual amount you need to spend to run the system will vary depending on the unit you have.

You should also service your cooling system at least once a year, at a cost of £70 to £120 each time. If an engineer finds any parts need replacing, these can run up to hundreds of pounds.

Keeping your cooler in good nick will reduce running costs in the long term.