Air Conditioning Frequently Asked Questions

Yes, Airconco provides free site surveys, subject to the conditions for your property.

For flats and apartments, we require written confirmation from your managing agent that the proposed installation is permitted before we carry out a free survey. In our experience, around 95% of leases include a restrictive covenant covering this type of work. If you would like a survey before permission has been granted, the current fee is £240 + VAT. This fee is refundable against the installation cost if you proceed with Airconco.

A survey helps us understand your property, assess suitable equipment, and identify any installation requirements that could affect the quotation.

Next step: Find out about our air-conditioning installation service/.

The cost depends on the equipment, number of rooms, cooling and heating requirements, installation complexity, and any additional work needed at your property.

For example, installing a single-room system is generally a different project from installing several units across a large home or commercial building. Electrical upgrades, access requirements, and the position of the outdoor unit can also affect the price.

Airconco can provide a budget estimate through our AC price calculator. A site survey may be needed to confirm the specifications and final quotation.

Yes and no. For commercial entities we are able to recommend leasing options for 3-5 year deals.

Unfortunately, we cannot lease to domestic customers.

Domestic units that are not in constant use and are used for cooling only generally require one service per year. Units that are in offices should be maintained at least twice per year to keep them running at their optimum level. For server rooms, we recommend at least three service visits per annum. For areas with high levels of pollution or contaminants in the air such as kitchens, hairdressers or workshops, additional service visits are carried out.

Regular servicing and maintenance keep your unit running at maximum efficiency, significantly extends the lifetime of a unit and reduces operating costs. In addition, routine maintenance will ensure that the unit qualifies for the full warranty of up to ten years rather than just the standard manufacturer’s one year warranty.

There are several reasons why your system is leaking water.

The condensate that is produced in the coils on the indoor part of your system should fall into a drip tray which is either drained away by gravity or pumped outside.

If excess water is finding its way down your wall then it’s more than safe to assume that much or all of the condensate is not being drained away.

Sometimes the drain hole might clog up with dirt, so the water obviously finds the easiest route to drain away which can’t be anything other than down your wall! However, if the condensate is being drained away with help from a pump, then there is every probability that the pump may have failed and this will obviously need replacing quickly. So often we find that the coils in the system have been so caked up with dirt that it has ended up blocking the unit drainage system.

A leak can be caused by something as simple as a dislodged drainage pipe, making the water drain upwards, which, of course, eventually flows back into the unit and down your wall. In this case, it’s a simple matter of correcting the angle of the drainage pipe.

Finally, and in more serious cases, should the system have leaked a large quantity of refrigerant, this will cause the coils on the indoor unit to “ice up” which will also result in leakage when the ice melts. If you do see ice on the coils, it is vital to switch the unit off immediately and call your air conditioning engineer.

Finally, and I’m sorry to hammer the point home as I have in our other videos, but so many of these problems would not happen if your unit was regularly maintained.

No. We believe that all units should be correctly specified and professionally installed by qualified engineers from a recognised air conditioning company. If we provide 'supply only units, we have no control over their final installation.

Yes, Airconco provides free site surveys, subject to the conditions for your property.

For flats and apartments, we require written confirmation from your managing agent that the proposed installation is permitted before we carry out a free survey. In our experience, around 95% of leases include a restrictive covenant covering this type of work. If you would like a survey before permission has been granted, the current fee is £240 + VAT. This fee is refundable against the installation cost if you proceed with Airconco.

A survey helps us understand your property, assess suitable equipment, and identify any installation requirements that could affect the quotation.

Next step: Find out about our air-conditioning installation service/.

We aim to offer competitive prices and believe that comparable quotations should be assessed on a like-for-like basis.

Before comparing prices, check that each quotation covers the same equipment, cooling capacity, installation work, electrical requirements, warranty, and aftercare. A lower initial price may not include everything needed to complete the installation.

If you have a competing quotation, send us the details, and we'll review what is included.

Next step: Read our guide to comparing air-conditioning quotes.

The cost depends on the equipment, number of rooms, cooling and heating requirements, installation complexity, and any additional work needed at your property.

For example, installing a single-room system is generally a different project from installing several units across a large home or commercial building. Electrical upgrades, access requirements, and the position of the outdoor unit can also affect the price.

Airconco can provide a budget estimate through our AC price calculator. A site survey may be needed to confirm the specifications and final quotation.

Our expert surveyors and engineers have many years experience in the industry. When there are various options or solutions, we provide you with all the information you will need to make an informed decision.

There is no single brand that is best for every property. The right choice depends on your budget, room size, system requirements, preferred features, appearance and warranty.

Airconco supplies and installs systems from Daikin, Gree, Mitsubishi Electric, Mitsubishi Heavy Industries, Samsung and Fujitsu. Our team can help you compare suitable options rather than choosing equipment based on the brand name alone.

Airconco also holds specific manufacturer credentials, including Daikin D1+ Premium approved contractor status for split and Sky Air product ranges, Fujitsu approved installer status, and registered distributor and installer status for Gree fitted systems.

Next step: Compare the options in our air-conditioning manufacturer guide.

First, go to the ‘CoolCulator’ on our website, where you can answer a few simple questions to get a budget estimate. Another option is to call us, and one of our experienced sales team members can help.

Yes. Our surveys and written quotations for new fitted air conditioning installations are free of charge. That means you get proper expert advice before you commit, and it gives us the chance to recommend the right system rather than a one-size-fits-all answer. We have been doing this since 1986, so we know a good installation starts with a careful survey and honest advice.

Yes. In many cases, we can give you a very useful ballpark figure before the survey, especially if you can tell us the room size, how the space is used, and what type of property it is. We then confirm everything after the site visit and turn that into a proper written quotation. It is a good way to get a feel for budget early on, while still making sure the final price is based on the right specification.

In most cases, yes. We can often give you a sensible guide price before we visit, but the survey is where we properly measure the room, assess the heat load, check pipe and drain routes, review electrics, and work out the best positions for the indoor and outdoor units. It is the difference between a rough idea and a system that is properly designed. We would always rather specify the right solution than guess, especially when we are backing the installation with a 10-year warranty.

We talk through how you use the room, what matters most to you, and which styles of units are likely to suit the space best. We also assess glazing, ceiling height, access, drainage, electrics, noise, outdoor-unit location, and appearance, so the final design works in the real world and not just on paper. By the end of the visit, you should have a much clearer idea of the best options, the likely costs, and what the installation would involve.

Our quotation is designed to be clear and upfront. In most cases it includes the equipment, standard installation materials, labour, commissioning, and normal handover, with any special items or work outside scope shown separately. That way you can see exactly what is and is not included and compare quotations on a like-for-like basis. We believe transparent quoting is one of the reasons customers trust us with both small domestic jobs and major commercial projects. 

Very often it comes down to the quotation not being like for like. Cheaper quotes can hide undersized equipment, excluded electrical works, lower-grade products, rushed installation methods, or weaker aftercare. The headline figure may look attractive, but it can end up being poor value if the system underperforms or problems appear later. We would always encourage you to compare the detail, the warranty, the equipment brand, and the service behind the price, and not just the cheapest number on the page.

If you have received a comparable quotation elsewhere, send it over, and we will review it properly. If it is genuinely like-for-like, we will always do our best to match it. The important part is making sure it really is comparable in terms of equipment, scope, warranty, and workmanship. We are very competitive, but we will not cut corners just to win a job, because that only stores up problems for the customer later.

You will need to clean the outside of the unit of any dust and frequently check and clean the air conditioning unit’s filter. Ensuring you clean your aircon filter during periods of heavy use and throughout the year will only maximise its performance and efficiency. To learn more about cleaning your Air Conditioning Filter, click here

We provide a comprehensive maintenance service. While many air conditioning companies simply hover your filters and leave, we fully service both the indoor and outdoor units, making sure that they are operating within normal parameters and are running at their full capacity.

Maintenance should always be carried out by a certified air conditioning engineer. It is not a simple case of just cleaning the filters. There are specialist tools required that only expert air conditioning technicians are qualified to use.

Air conditioning filters do not necessarily need to be replaced; they only need to be cleaned. Most filters require cleaning twice a year; however, if the system is heavily used or in dusty areas, the filters may require more frequent cleaning.

We are happy to quote for servicing and repairs to your systems even if we did not originally provide the installation. Please call our service department who can provide an estimate.

Domestic units that are not in constant use and are used for cooling only generally require one service per year. Units that are in offices should be maintained at least twice per year to keep them running at their optimum level. For server rooms, we recommend at least three service visits per annum. For areas with high levels of pollution or contaminants in the air such as kitchens, hairdressers or workshops, additional service visits are carried out.

After we have installed your system, we can offer a full range of backup services ranging from simple telephone support to regular on-site maintenance programs. We will service and repair your equipment for as long as you want regardless of whether it is still under warranty or not.

Regular servicing and maintenance keep your unit running at maximum efficiency, significantly extends the lifetime of a unit and reduces operating costs. In addition, routine maintenance will ensure that the unit qualifies for the full warranty of up to ten years rather than just the standard manufacturer’s one year warranty.

Maintenance is planned preventative care designed to keep a system clean, efficient, and reliable. Repair is what you need when something has already failed, stopped working properly, or is showing a clear fault. In other words, maintenance prevents problems, and repair fixes them once they occur. The two are closely linked, and we recommend regular servicing because it helps reduce the number of repair call-outs later on.

Regular servicing helps your air conditioning run more efficiently, last longer, smell fresher, and break down less often. It also helps keep running costs under control and is usually needed if you want warranty cover to remain valid. Many avoidable faults start with dirt, blocked drainage, neglected filters, or poor airflow, so maintenance is not an optional extra if you want the system to perform properly. A good service usually costs far less than a breakdown.

For most home systems, once a year is the sensible minimum. If the unit gets heavy summer use, runs in heating mode through winter, or sits in a dusty environment, twice a year can be even better. The ideal timing is usually before the hot weather starts, so the system is clean and ready when you need it. Preventative servicing is always better than finding out there is a problem on the first really warm day of the year.

For offices, six-monthly servicing is a common and sensible standard. Commercial systems tend to run for longer hours, serve more people, and work harder than domestic units, so they benefit from more regular attention. In busier or more critical environments, quarterly visits may be the right answer. We can advise on the most suitable schedule, but the key point is that offices usually need a more structured maintenance plan than a lightly used home system.

Server room air conditioning should be serviced at least twice a year, and in many critical environments quarterly maintenance is the safer choice. These systems often run hard, run continuously, and protect equipment that simply cannot be allowed to overheat. Because the cost of downtime can be far greater than the cost of servicing, server room maintenance is one of the easiest areas to justify proper preventative care. We would always rather catch a weakness early than deal with a failure in an emergency.

Yes, very often they do. Kitchens, salons, workshops, gyms, and other high-load or contaminated environments tend to put more strain on an air conditioning system because of grease, dust, aerosols, moisture, or long operating hours. Filters and coils can become dirty much faster, which affects efficiency and reliability. In those kinds of spaces, a standard annual service may simply not be enough. We can set up a more suitable schedule so the system keeps performing as it should.

A proper maintenance visit should be much more than a quick wipe-over. We check and clean filters, coils, fans, condensate trays and drains, pumps where fitted, electrical connections, operating temperatures, and general performance. We also inspect the outdoor unit, because that is just as important as the indoor one. The aim is to leave the system cleaner, safer, and running within normal parameters - and to spot wear early before it becomes a breakdown.

In most cases, yes. Maintenance contracts are usually cheaper overall than repeated one-off services, and they also make life easier because visits are scheduled instead of being forgotten until something goes wrong. Contracts are particularly useful for businesses, landlords, and anyone with multiple systems to look after. They help with budgeting, warranty compliance, and record keeping too. A planned approach nearly always works out better than a reactive one, both technically and financially.

Yes. We are very happy to maintain systems that were installed by other companies. In many cases the first visit gives us the chance to assess the condition of the equipment, note any existing faults, and then put the system onto a sensible service schedule from there. Plenty of our maintenance clients originally came to us because they were unhappy with their previous provider. Good maintenance is about the standard of the service now, not who fitted the system years ago.

Yes. Regular servicing is usually a condition of ongoing warranty cover, especially if you are relying on an enhanced warranty rather than a basic manufacturer position. Maintenance helps show that the system has been looked after properly and that avoidable damage has not been caused by neglect. It is one of the reasons we are so strong on maintenance after installation. A 10-year warranty only has real value when the system is serviced in line with the required terms.

Typical signs include weaker airflow, stale smells, reduced cooling or heating, higher running costs, unusual noises, icing, water leaks, or a room taking much longer to reach temperature than it used to. Sometimes the change is gradual, which is why systems are often overdue a service before the customer realises it. If the unit just does not feel as fresh, quiet, or effective as it once did, that is usually a good sign it wants professional attention.

Absolutely. Dirty filters make it harder for the system to move air, which reduces performance, increases energy use, and can contribute to icing, poor comfort, and wear on components. It is one of the simplest issues on paper, but one of the biggest causes of poor performance in real life. A system that cannot breathe properly cannot work properly. That is why even between professional visits, keeping an eye on filter condition is well worth doing.

Simply put, not all portable air conditioning units will have a hose attached; we will look at that in more depth in a moment, but first, let us start with the types of aircon units we can use in our properties for portable use. To learn more click here.

All air conditioners need to exhaust hot air from the room it is trying to cool. The most common exhaust method used on portable units is via a 6 inch (15.2 cm) flexible hose (on more industrial units this can be significantly wider).

In most cases, this hot air is also exhausted along with the excess humidity in the room, so the hose must be vented into the outside atmosphere (e.g. a window or external door).

There are a few exceptions to this rule, some dry exhaust air conditioners can be vented into a suspended (false) ceiling or into a spare room that you don’t mind getting hot. These units have built-in water tanks which allow the units to expel hot, dry air out the hose. You may need to empty the water tank a few times per day.

Here our Recommendations for Dry Exhaust Air Conditioners:

To Hire in Offices
· Gree 3.2kW (11,000 BTU)

To Buy for Server Rooms
· Ex-Hire Airrex HSC-2500 or Ex-Hire Airrex HSC-3500

To Hire for Server Rooms and Shops
· Airrex HSC-2500 6.1kW or Airrex HSC-3500 7.3 kW

In order for air conditioners need to cool a room, they need to get rid of the excess heat they create.

Air conditioners contain a refrigerant gas that needs to be pumped through a special expansion valve to get exceptionally cold. A powerful compressor is used to achieve this flow of refrigerant gas. The continual use of the compressor creates excess heat, and it’s that heat that needs to be exhausted to the outside atmosphere (through a window or an external door).

The internal compressor gets very hot in the process and this excess heat must be exhausted away. The usual method of exhausting away the hot air is with a hose that needs to go out a window or a door to the outside.

Portable air conditioning is designed for temporary or flexible cooling. It is plug-in, movable, and very useful when you need a quick solution without a full installation. Fitted air conditioning is the longer-term answer: it is usually quieter, neater, more powerful, and better for regular everyday use. In simple terms, portable is ideal for short-term needs or urgent cooling, while fitted is usually the better investment if you want a permanent comfort solution.

Yes. We hire portable air conditioners within London and can advise on the right size and type of unit for the room you need to cool. Portable hire is particularly useful for temporary problems, hot bedrooms, overheated offices, events, or situations where a fitted system has failed. Because portable cooling is part of our business rather than a sideline, we can normally guide you quickly and practically rather than leaving you to guess which unit might work.

Yes, in many cases we can offer same-day delivery in London if the order is placed before 1pm, subject to stock, routing, and how busy the day is. If you have an urgent requirement, the best thing to do is call us as early as possible so we can confirm availability straight away. Fast temporary cooling is one of the reasons many customers come to us when they need a problem solved now rather than next week.

Yes. We sell portable units across mainland Britain, so if you are outside London and want to buy rather than hire, we can usually help. London hire is where our rental service is focused, but sales are available much more widely. If you are not sure whether hiring or buying makes more sense, tell us how long you expect to need cooling for and we can point you in the right direction.

Portable units are good for bedrooms, home offices, meeting rooms, shops, temporary workspaces, server rooms with the right model, and spaces that need quick, short-term cooling. They are especially useful when a fitted installation is not possible straight away or when you do not want permanent works. The main thing is to match the unit properly to the room and the heat load. A well-chosen portable can work very well; the wrong one will disappoint.

A portable air conditioner pulls warm room air across a cooling system, removes heat from it, and then blows cooler air back into the space. The heat it has removed has to go somewhere, which is why the unit uses an exhaust hose to discharge that warm air out of the room. Many models also remove moisture from the air at the same time, so they can make the room feel more comfortable in two ways, not just by lowering the temperature.

Not effectively, no. If the hose is not vented outside or into a proper exhaust route, the heat the unit removes from the air is simply released back into the room. The machine may still blow cool air from the front, but overall the room will not cool properly. This is one of the biggest misunderstandings with portable air conditioners. They absolutely do work, but only when they are set up in the right way.

If there is no suitable opening, we need to think carefully before recommending portable air conditioning. In some cases a window kit, fabric seal, door route, or another venting arrangement solves the problem. In others, a portable may simply not be the right answer and it is better to say so honestly. We would rather guide you to the right solution than sell or hire something that will never perform properly in your space.

Yes, generally they are easy to set up. Most units simply need to be positioned sensibly, plugged into a suitable power supply, and connected to the exhaust hose and window or vent kit. If the unit has been transported, it is often wise to let it settle briefly before use. We can talk you through the basics, and because we deal with portable cooling every day, we can usually help customers avoid the common setup mistakes.

Portable units are noisier than fitted systems because the working parts are in the room with you rather than outside or hidden away. That said, some are perfectly acceptable for daytime use in bedrooms, home offices, and commercial spaces when expectations are realistic. If low noise is the absolute priority, fitted air conditioning usually wins. Portable is a compromise between speed, flexibility, and convenience on one hand, and noise and neatness on the other.

Yes, many people do, especially during hot spells. The main thing to understand is that a portable unit will normally be more noticeable than a fitted bedroom system, so light sleepers may find it less ideal. If you need an urgent bedroom cooling solution, portable can be a real lifesaver. If you want the quietest long-term answer for sleeping comfort, fitted air conditioning is usually the better route.

Yes. Portable air conditioners remove moisture from the air as part of the cooling process, which is one reason they can make a room feel more comfortable quite quickly. That dehumidifying effect is especially noticeable in warm, sticky weather. It is also why some units may collect condensate or use self-evaporating systems depending on the model and the conditions. So you are usually getting cooling and dehumidification together.

Sometimes. Many modern portables self-evaporate a lot of the moisture they remove, but some units still need water emptied in certain conditions, especially in very humid weather or when used heavily. The answer depends on the model and the environment. If a tank does need attention, it is usually simple and easy. We will always explain the practical side of the unit you are hiring or buying so there are no surprises once it is in use.

Not well. A portable AC unit is usually best treated as a one-room-at-a-time solution. If you leave doors open and expect it to cool several rooms at once, performance will drop quickly. Portables work best when they are matched to the space, the doors are kept shut as much as practical, and the cooling is concentrated where it is needed. If you need to cool multiple rooms regularly, fitted air conditioning is often the better answer.

The right size depends on more than just floor area. We also look at glazing, ceiling height, occupancy, equipment, solar gain, and how quickly you need the room to pull down. Choosing by room size alone is one reason people sometimes end up disappointed. Tell us about the space and we can guide you towards a unit that is more likely to perform well, rather than simply picking the biggest or cheapest machine available.

It depends what result you actually need. A portable air conditioner is the answer when you want refrigerated cooling room. An evaporative cooler can be helpful in dry, well-ventilated spaces, but it does not lower room temperature in the same way and is much more limited in humid weather. A fan does not cool the air at all - it simply moves it. So if you want genuine cooling, portable air conditioning is usually the clear winner.

Some portable AC in London are suitable for server rooms, but not every domestic-style unit is a good fit. Server environments often need stronger, more specialist temporary cooling and careful hose management, especially if the heat load is high. The important thing is not to guess. Tell us about the room, the equipment, and the urgency, and we can recommend whether a portable unit is suitable and what type stands the best chance of protecting the space properly.