One factor that can dissuade someone from extending their home with a conservatory is the 'hothouse' effect in the summer. Glass magnifies the sunlight, and whilst this can be a wonderful feature in the winter, come the summer the conservatory can become unbearably hot. This is particularly relevant if your conservatory is to be built facing south-west (in the UK), where it will have sun shining on it for most of the day.

Blinds provide one solution, but then you lose the light, one of the main reasons people choose a conservatory over an extension with a closed roof. The most effective solution is air conditioning. This has become much more affordable in recent years and modern air-conditioning units now provide the added benefit of a heating supply in the winter.

Portable or Fixed?

There are essentially two ways to install air conditioning in your conservatory: portable or fixed. If you choose the portable option, not only is this very affordable with prices starting from £230 for smaller units, but it also does not require an external unit and the necessary holes to be drilled through to it from the internal unit. Instead, ducting simply takes the warm air outside from the unit through a window or open door.

Fixed systems do require both an internal and external unit, and careful consideration should be given to the location of both units before installation. The external unit will generate heat and noise, and it can spoil your barbecue if it is located right next to your seating area outside. The internal unit will blow cold air (as you would want) but again this can be uncomfortable if it is directed straight at the back of your neck.

Fixed air-conditioning systems are best fitted when you actually build the conservatory, and a reputable conservatory firm will be able to advise you on specifically where you should best place both the internal and external units as part of your overall design. This is important because fixed systems require a hole through to the outside for the ducting, as well as an electrical supply. The internal unit can be placed high on the wall and a remote control used to operate all functions. It is worth noting that you will want to familiarise yourself with the function for changing the vertical direction of the air. Because in the summer the cold air is best directed upwards as it will drop, whereas in the winter the warm air is best directed downwards where it will rise. Having warm air directed at the seating area is not so unwelcome in the winter, whereas the cold air would be in the summer.

Thermostats and Dehumidification

A real advantage of air conditioners is that they are thermostatically controlled, including most portable units and all fixed units. This means you can find your preferred temperature and keep the conservatory at that point, both when cooling and when heating. In a conservatory setting this is likely to be more accurate than a central heating thermostat as it is a single, isolated space. Another bonus of an air-conditioning unit is that it will remove moisture from the air inside your conservatory. This is often what causes the discomfort on hot days. A dry heat, such as that in a desert location like Las Vegas, is much more bearable than a wet, humid heat such as that of New York City in the summer. If you have experienced these very different kinds of heat, you will immediately see the potential benefit of a system that reduces the humidity of a room. When we do enjoy a hot British summer, it is often accompanied by heavy humidity.

How Many Kilowatts?

The key factor in choosing an air conditioner is how much power you need, that is how many kilowatts (KW) can the unit generate to cool your room. What you will need depends on the size of your conservatory (height as well as width and length) and which way it faces (north or south). It also depends on whether you intend to cool/heat just the conservatory or the adjoining room too. When calculating what you need, you should be aware that this is only applicable if that space is closed (doors and windows) otherwise the unit will attempt to heat/cool the space until it reaches a closed door or window. You wouldn't want to leave your windows open and let it attempt to cool the entire garden.

A good conservatory designer will quickly be able to tell you what you will need, and can advise on the heating aspect too. But as a rough guide: smaller, north-facing conservatories measuring 4 metres by 3 will only need a 2.5 KW unit; whereas larger conservatories or those that face southwards, will need 3.5 KW or even 5KW. The higher the kilowatts the higher the price for the unit.

Heat Pumps

If you are intending to use the air conditioner as a heater in the winter then you should consider what kind of heat pump it employs. Many air-conditioning systems will cope with heating a room if the outside temperature is above zero degrees Celsius, but once it drops below that they will become erratic and eventually shut down at very low temperatures. By paying a little extra, you can purchase a system fitted with technology that will be able to cope with sub-zero temperatures. In recent years this has become more relevant in the UK, with winters that saw thermometers regularly drop below zero. Again, a reputable conservatory firm will be able to give you advice specific to your needs.