Cooling
A conservatory is a lovely room for about three weeks of the year. For the rest of summer it can be like sitting in a greenhouse, and in winter it is often too cold to use at all. If you have given up on yours and started using it as a dumping ground for drying washing, you are far from alone. The good news is that a properly specified air conditioning system turns a conservatory into the room you actually wanted, usable right through the year.
We have cooled a lot of conservatories across the North-East and the physics is always the same. Understanding why they overheat is the key to fixing it properly rather than throwing money at something that will not cope.
It is worth saying at the outset that a conservatory is not a hopeless case. Plenty of people assume that because it is mostly glass it can never be comfortable, and they resign themselves to only using it in spring and autumn. That is not true. With the right system, sized and positioned properly, a conservatory can be one of the nicest rooms in the house to sit in on a hot day, cool and fresh with the garden on view. The trick is respecting what you are dealing with rather than treating it like any other room.
Why conservatories get so hot
A conservatory is mostly glass, and glass is brilliant at letting heat in and poor at keeping it out. On a sunny day the sun pours straight through the glazing and the roof, warms every surface inside and the room heats up fast. This is called solar gain and a conservatory gets more of it than any other room in the house. A polycarbonate or glass roof is the worst offender because the sun is highest and strongest overhead through the middle of the day.
On top of that, a conservatory often has poor ventilation and thin construction compared with the brick-built rooms around it. Heat floods in quickly and has nowhere to go. That is why a conservatory can hit uncomfortable temperatures when the rest of the house still feels pleasant. Cooling one is a bigger job than cooling an ordinary room of the same size and it needs to be treated that way.
The same thin glassy construction that lets heat flood in during summer lets it pour straight back out in winter. Glass is a poor insulator, so the warmth you put into the room leaks away fast, which is why a conservatory that is unbearable in July is often freezing by December. This swing between extremes is the defining feature of the room and it is exactly why a one-season fix, like a fan in summer or a plug-in heater in winter, never really satisfies. You need something that deals with both ends of the year.
Why portable units struggle
The first thing many people try is a portable air conditioner from a shop. We understand the appeal, but in a conservatory they almost always disappoint. There are a few clear reasons for that.
- Not enough capacity. A portable unit simply cannot remove heat fast enough to keep up with the solar gain pouring through all that glass.
- The hose problem. A portable has to vent hot air out through a hose, usually jammed through a gap in a door or window. That open gap lets warm outside air straight back in, which partly undoes the cooling.
- Noise and clutter. They are loud, they take up floor space and they drip into a tank you have to keep emptying.
- Running cost. Because they fight a losing battle, they run constantly and are inefficient for the comfort they deliver.
A portable is a sticking plaster. For a room that overheats as hard as a conservatory does, it is rarely the answer.
A properly sized wall split is the real fix
The proper solution is a fixed wall-mounted split system. That is the slim indoor unit you see high on a wall, linked by small pipework to a compact outdoor unit. It is quiet, it is efficient and, crucially, it can be sized to match the heat load of your particular conservatory rather than a one-size-fits-all box off a shelf.
Because the outdoor unit sits outside and rejects the heat properly, there is no hose and no open gap letting warm air back in. The indoor unit just quietly cools, filters and dehumidifies the air. On the hottest days it will hold the room at a comfortable temperature where a portable would be flat out and losing.
A fixed split also looks the part. The indoor unit is a slim neat panel high on the wall rather than a bulky box cluttering the floor, and once the pipework is run and the outdoor unit sited it simply becomes part of the room. There is nothing to put away at the end of summer and nothing to drag out again next year. You switch it on with a handset or your phone and forget about it, which is how it should be.
Sizing for all that glass
This is the part that matters most and the part a lot of people get wrong. A conservatory needs more cooling capacity than its floor area alone would suggest, because of all the glazing and the solar gain. Sizing it like an ordinary room will leave you with a unit that cannot cope on the days you most want it.
When we survey a conservatory we look at far more than the floor size. We take account of which way it faces, how much glass there is and whether the roof is glass or polycarbonate, how exposed it is and what shading it has. A south or west-facing conservatory with a glass roof needs noticeably more capacity than a shaded north-facing one of the same size. Getting this right is the difference between a room that stays comfortable and one that is still too warm with a brand new unit on the wall.
There are a handful of things we weigh up on every conservatory survey, and they all push the sizing in the same direction.
- Aspect. Which way it faces decides how much sun it takes and when, with west-facing rooms copping the fierce late afternoon sun.
- Roof type. A glass or polycarbonate roof lets in far more overhead heat than a solid or insulated one.
- Extent of glazing. Floor-to-ceiling glass on three sides is a very different job from a dwarf wall with windows above.
- Exposure. An open, unshaded spot takes more sun than one tucked behind trees or a fence.
- Existing shading. Blinds or solar film already fitted reduce the load and we factor that in.
Err on the side of a little more capacity rather than a little less. A unit with headroom will cruise on a hot day and sip energy, while one sized right to the limit will be flat out and struggling exactly when you want it most. We would always rather specify a system that copes comfortably on the worst day of the year than one that just scrapes by.
Positioning the indoor unit
Where the indoor unit goes makes a real difference to how well it performs and how it feels in the room. In a conservatory the choices can be a little tighter because so much of the structure is glass and frame rather than solid wall.
- High on a solid wall. Mounting it high lets cool air spread across the room and fall gently rather than blasting anyone sitting below.
- Away from direct seating. You do not want it pointing straight at the sofa, so we aim the airflow to circulate rather than dump cold air on one spot.
- Sensible pipe routing. The link to the outdoor unit needs a tidy, short run where possible, which is part of what we plan on the survey.
It heats in winter too
Here is the part people often miss. The same system that cools in summer is a heat pump, so it heats the conservatory efficiently in winter. That means the room that was unusable in July because it was too hot is also usable in January when it would otherwise be too cold. One system, both problems solved, and a conservatory you get the full value from all year rather than for a few weeks.
Heat pump heating is efficient because it moves heat rather than burning fuel to make it, so it is a sensible way to take the chill off a glassy room that loses warmth quickly. For a lot of our customers this is the deciding factor, because it turns a seasonal room into a proper extra living space.
Because the unit responds quickly, you are not heating an empty room all day waiting for it to be usable. You can bring the conservatory up to temperature in a reasonable time before you want to sit in it, then let it ease back. With a timer or an app you can have it warm and waiting for a Sunday morning with the papers, or take the chill off for an hour in the evening, without leaving it running when nobody is there. A conservatory with this kind of heating stops being the cold room at the back of the house and becomes somewhere you genuinely choose to spend time.
Blinds and solar film help, but only so far
You will see blinds and solar reflective film sold as the answer to a hot conservatory. They do help and we would never talk you out of them, but it is important to be honest about what they do. They reduce the amount of heat getting in, which eases the load. They do not actively cool the room or remove heat that is already there, and on a genuinely hot day they are not enough on their own.
Think of shading as a partner to air conditioning rather than a replacement for it. Good blinds or film cut the solar gain, which means the air con has less work to do and runs more economically. Together they keep a conservatory comfortable far better than either does alone. If you already have blinds, tell us on the survey because it affects the sizing.
The same goes for an insulated roof if you have had one fitted, or are thinking about it. Replacing a bare glass or polycarbonate roof with an insulated one cuts a huge amount of the overhead heat gain in summer and the heat loss in winter, and it pairs beautifully with air conditioning. You still want the air con for the glazed walls and for proper control of temperature and humidity, but the combination makes the room comfortable with a smaller, cheaper-to-run system. If a roof upgrade is on the cards, it is worth mentioning when we survey so we can size around it.
Talk to Air Con North
If your conservatory is too hot to use in summer and too cold in winter, we can make it a room you actually enjoy. We design, supply and install quiet efficient cooling and heating for conservatories across the North-East, from Durham and Sunderland to Gateshead, Newcastle, Middlesbrough and beyond, and with over 25 years in the trade we know how to size one properly. Call us free on 0800 246 5430 for a no-obligation survey. We will measure up, take account of your glazing and aspect and recommend a system that genuinely keeps the room comfortable all year.
