Ten Things To Consider About Conservatories
4. Heating and Cooling
All rooms in the home require heating and that is no different with conservatories – just more so. Most rooms however, can manage, in this country at least, without cooling, but it can be an important requirement in some conservatories, especially those which are south facing.
Here, we consider the different forms of heating, including underfloor heating, natural ventilation & air conditioning, the use of tilt & turn windows, conservatory window & roof blinds and the problem of condensation.
Heating in your conservatory
There is a wide range of heating choices available to the new conservatory owner but to satisfy Building Regulations the system must have its own separate control system to the rest of the house.
If your existing central heating boiler can cope with additional radiator(s) for another room, the simple answer is to extend the central heating system into your conservatory – though it must be fitted with a thermostatically controlled valve.
A variety of other heating systems are also available, including fan heaters, oil filled radiators, storage heaters and under floor heating.
Underfloor heating in your conservatory
Under floor heating was employed by the Greeks and Romans in around 500 BC but can actually be traced back to 5,000 BC from archaeological digs in the Middle East. Modern under floor heating systems can use either hydronic or electrical systems.
Hydronic systems use water, sometimes with anti-freeze added, which is re-circulated within pipes generally made from polyethylene. The fluid is heated by a boiler and pumped around a system of pipework underneath the floor and requires installers with skills similar to central heating installers.
The addition of a chiller unit means that some hydronic systems can also be used to cool the conservatory. Electrical systems are used for heating only and use flexible heating elements often embedded in pre-formed mats which are normally much thinner than the pipework in hydronic systems and easier to install.
Natural ventilation and air conditioning in your conservatory
As for cooling a conservatory, there is no substitute for designed-in natural ventilation – this can consist of simply windows which open, or a proprietary eaves and ridge ventilation system.
Some designers and installation companies will limit the number of opening windows in their proposed specification simply to keep their quotation low and improve their chances of winning your business – this is false economy in the extreme. And although air conditioning may be appropriate for some conservatories, it should never have to be installed purely to compensate for the lack of natural ventilation which should have been included in the original specification.
Tilt and turn windows in your conservatory
Tilt and turn windows should be strongly considered due to their large size and method of operation. When tilted inwards, any breeze from outside the conservatory will be directed towards the hottest area of the conservatory (the roof space).
Alternatively, when a tilt and turn window is swung open into the conservatory, it provides almost as much ventilation as a door. The British Board of Agrément (the body which assesses and registers building products) recommends that the minimum area of opening windows and doors to provide ventilation in a conservatory should be 15% of the floor area. This compares with a Building Regulations rule for other rooms in the house of 5%.
Another advantage of tilt and turn windows is that no horizontal transom bar is required as with outward opening casement windows. Horizontal transom bars in conservatory windows tend to be in the line of sight when you are standing, potentially spoiling the view of your garden.
Conservatory blinds in your conservatory
Another popular method of cooling a conservatory or orangery – at the same time as providing a degree of privacy – is by installing window or roof blinds. A wide choice of blinds is available but pleated, roller and Venetian blinds are probably the most popular for conservatories.
Blinds can also be installed in the roof but for conservatory roofs with triangular panels, roof blinds can be quite expensive, so the cost should be factored in at the time of budgeting for your conservatory – it may convince you to choose solar control glazing instead, or perhaps a different style of conservatory and roof.
Dealing with condensation in your conservatory
Condensation can be one of a conservatory’s worst enemies due to the large expanse of glass in the structure. Energy efficient windows and doors, loft insulation and fitted carpets have all contributed to making homes less draughty by virtually eliminating natural ventilation.
They can however, result in an increase in condensation due to this lack of natural ventilation. Water vapour is produced naturally as a bi-product of normal day-to-day living such as washing, cooking and simply breathing and the warmer the air the more water vapour it can hold.
When air can hold no more water vapour it is said to be saturated and when saturated air comes into contact with a surface cooler than itself – such as the glass in your conservatory – the air cools and therefore cannot hold as much water vapour.
The excess water vapour is deposited onto the glass, firstly as mist then in larger amounts as water droplets. The greater the temperature difference between the air and the glass, the more condensation there will be. Because argon is denser than air, argon-filled insulating glass sealed units will keep the inner sheet of glass warmer than air-filled sealed units would and therefore help to reduce condensation.
The situation with day-to-day condensation should not be confused with the initial condensation which appears just after a conservatory is built. Many gallons of water are used in the conservatory base, floor and dwarf walls during construction and these have to be allowed to dry out.
Opening windows and doors during dry, breezy days will generally work better than just heating. Heating the conservatory will allow the air inside to hold more water vapour so the condensation will simply evaporate and condense again later once the conservatory cools down.
Opening windows and doors allows the saturated air to escape and be replaced with drier air. De-humidifiers are also sometimes used to extract water vapour from the air but drying out too quickly may cause cracking on a screeded floor or plastered wall surface.
Ten Things To Consider About Conservatories