It’s worth speaking in terms of energy not just heat. Sunlight bouncing off a reflective curtain and going outside is one of their benefits.
An awning is a net benefit over a curtain alone, but there’s overlap in functionality so having a curtain reduces the net saving from adding an awning.
An awning is a net benefit over a curtain alone, but there’s overlap in functionality so having a curtain reduces the net saving from adding an awning.