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Greenhouse Thermal Screens and Energy Curtains
A thermal screen is a movable layer that holds heat in at night and cuts heating demand. FANGCHENG supplies thermal screens and insulation as part of the greenhouse, and plans them with the heating and ventilation systems.
Where greenhouse heat goes at night
After sunset the house loses heat through the cover and through leaks, and it radiates heat to the cold night sky.
Heat escapes through the cover and through leaks.
The screen adds a layer.
The roof is far from the crop.
It sits closer to the crop than the roof.
The house radiates heat to the cold night sky.
A reflective screen sends heat back down.
Tap a side, or the photo, to compare.
How thermal screens save energy
They shrink the surface that loses heat, because the screen sits under the roof
They trap still air above the crop, which acts as an extra insulating layer
They can reduce condensation dripping onto plants
They are drawn back in the daytime so the crop gets light
Types
Thermal curtain.
A fabric screen that holds heat in at night.
Aluminized screen.
Reflective strips send heat back toward the crop at night and can reflect sun in summer.
Combined shading and thermal screen.
One screen for both jobs, where the crop and climate allow.
Using the screen day to day
Close it at dusk
So heat is kept in.
Open it at dawn
So the crop gets light.
On humid nights
Leave a small gap so moist air can escape.
In winter
Run it with heating, so the system is not heating the whole volume of the house.
Screens and humidity
A closed screen can trap moist air under it. That is why screen control should be linked to humidity, and why ventilation has to be planned. A screen that is closed all night on a humid night can cause condensation problems.
Link screens to humidityInsulation beyond the screen
- Choose a cover with better insulation: polycarbonate, glass or double-layer film
- Seal the edges of the screen so warm air does not leak past it
- Close gaps at gables and sidewalls
Insulation options compared
Double-layer film.
An air gap between two layers cuts heat loss compared with a single layer. Lower cost.
Polycarbonate.
Hollow-wall sheet holds air inside it, so it insulates better than single glass or film.
Glass.
High light and long life. Insulation depends on the glass type, and a screen adds a lot.
Sealing.
Sealing gaps at doors, vents and gables stops leaks, which costs very little compared with extra heating.
What to check before you buy
Light loss: a screen that is drawn back should not block the crop
Humidity: closed screens can trap moisture, so ventilation must be planned
Drive and tracks: the screen moves every day
Payback: it depends on climate, fuel price and house type
Screen fabrics in plain terms
Clear or white fabric.
Lets light through while holding heat in, for use in light-hungry crops.
Aluminized strips.
Reflect heat and, in summer, sunlight. Can also be used for shading.
Dense or blackout fabric.
Blocks light as well as heat, and is used where light must be cut.
Light, retrofit and installation
The light trade-off
Every screen costs some light when closed. In low-light months the right fabric and a good control strategy matter, because a heavy screen that is closed too long can slow growth.
Retrofit or new build
Screens are easiest to plan into a new structure, because the frame is sized for the load and the tracks. They can often be added to an existing greenhouse if the structure can carry the weight.
Installation points
- 01
Tracks and drives that are strong enough for daily use
- 02
Tight edges and overlaps so air does not leak
- 03
Gables and sidewalls sealed as well as the roof
- 04
Access for maintenance above the crop
Common mistakes
Leaving gaps at the edges so warm air leaks past
Closing a screen on a humid night with no ventilation plan
Choosing the wrong fabric for the climate
Slow, weak drives
Judging a screen only by its energy rating and not by its light loss
Common questions
Straight answers. If yours is not here, ask us.
It varies with climate, greenhouse type and screen material. We do not quote a single figure. We estimate for your site.
Only when closed. Drawn back, they leave the crop in full light.
Often yes. Tell us the structure and we check.
They do different jobs and work together. A double cover reduces heat loss all day. A screen adds a layer at night and can be opened for light.
It depends on how many cold nights you have. In a mild climate it may not pay back. We help you decide.
Some can. Aluminized screens, for example, reflect heat out in summer and in at night.
Night temperatures hold better and heating runs less. Climate control can log this.
Screens sit inside the cover and do not carry snow. A heated, well-insulated cover still needs snow-load design. See our assessment service.
Explore other systems
Plan your insulation
Send your location, crop and greenhouse type. We reply within 24 hours.
Consultation and project proposals are free.
What to include
- Location
- Crop
- Greenhouse size
