Do top down cellular shades still block heat well?
Yes. The honeycomb cells trap air and reduce heat transfer even when the shade is partially open.
Will they sag when opened from the top?
No. Quality designs use reinforced rails and tension systems for even support.
Can they provide blackout performance?
Yes. Top down cellular shades can be made with blackout fabric, but full darkness requires careful inside or outside mount selection.
Are they good for street-facing rooms?
Absolutely. You can keep the bottom section closed for privacy while bringing in daylight from above.