A solar air heater is one of the simplest heating systems to install: no water, no fuel, no boiler. But almost all of its performance depends on where and how you place it. In this guide we explain, step by step, how to choose the spot, how to mount it and which mistakes to avoid.
1. Choose the right spot: direct sun and no shade
The collector heats the air with direct sunlight, so location is what matters most:
- South-facing. This is ideal. South-east or south-west also work, although the collector gets fewer hours of sun.
- No shade between 10 am and 4 pm. Look out for trees, neighbouring buildings, eaves or chimneys. In winter the sun is lower and shadows are longer than in summer: check it at that time of year.
- As close as possible to the room you want to heat. The shorter the air path, the less heat is lost on the way.
2. Wall, roof or ground: what tilt to give it
In winter the sun is low on the horizon, so a collector mounted vertically on a south-facing wall or steeply tilted makes very good use of the sunlight in the cold months. It also gets less dirty when vertical and does not collect snow.
You can also place it on a roof, a terrace or a frame on the ground. In that case, a steep tilt helps capture more sun in winter, which is when you will use it.
3. Fix it securely
Our collector measures 1300 × 1000 × 80 mm. As it is a large surface exposed to the wind, you should:
- Use anchors and plugs suited to the type of wall or support (brick, block, concrete, wood…).
- Check that the structure is firm and has no play.
- Keep the polycarbonate cover accessible so you can clean it.
4. Connect the flexible duct and the fan
The hot air reaches the room through a flexible duct; in our kit it is 102 mm in diameter. To get as much heat as possible to the room:
- Keep the duct run as short and straight as possible. Every metre and every bend reduces airflow and temperature.
- Insulate any section that runs outdoors or through cold areas.
- Seal the wall opening well so that no water or cold air gets in.
The fan is what moves the air. Usually you switch it on once the collector has warmed up, in the middle of the day. If you would rather not think about it, you can add a thermostat or a timer that switches it on only when the sun is out.
5. Indoor air or outdoor air
The collector can work in two ways:
- Recirculating room air: it takes in air from inside, heats it and returns it.
- Taking in outdoor air: it brings in fresh, warm and dry air. This is very useful in second homes, garages, basements or cellars that tend to build up damp.
6. Check that it works
With a simple thermometer at the duct outlet you can see how much it heats. In our test on 20 January 2024 in Valladolid, at 1:30 pm, with a perceived outdoor temperature of 2 °C, the air left the collector at 40 °C: a temperature rise of 38 °C. We explain it in detail in this article on temperature rise.
Common mistakes to avoid
- Placing it where it is shaded for part of the day, especially in winter.
- Long duct runs with lots of bends.
- Leaving the duct uninsulated where it runs outdoors.
- Switching the fan on before the collector has warmed up: at first you will only move cold air.
- Forgetting to clean the cover: dust and dirt reduce the light that gets in.
Shall we help you choose where to put it?
Send us a photo of the wall or roof where you would install it and we will tell you whether it is a good spot. You can see the prices and models or write to us directly.
Ask about my installation or call us on 686 227 287.