Cellular shades are the shade type most often discussed for insulation. Here is how they are built, what they can and cannot do and how to choose one.
A cellular shade, also called a honeycomb shade, is made from pleated fabric that is folded into hollow cells. When you look at the side, the cells form a honeycomb pattern. The shade raises and lowers as a stack, and it packs down compactly.
Cells can be single, double or sometimes triple layers, and the more layers there are, the more air pockets the shade holds. Fabric choices range from light-filtering to blackout. The construction is what sets the product apart from a flat roller shade, discussed in our interior roller and solar shades page.
Top-down, bottom-up versions let you lower the top of the shade while the bottom stays up, which opens a strip of light at the top while keeping privacy lower down. That feature is popular in bathrooms and street-level rooms, and it is available on a number of cellular designs, so ask whether the model you like offers it.
Still air resists heat flow better than moving air. The hollow cells trap air between the room and the window, which slows the transfer of heat across the window in winter and summer. A shade that fits snugly against the frame, with little air leaking around the edges, does the best job.
One building-science article noted that some cellular shades are marketed with an added R-value figure for the window opening, but R-values for window products depend on how they are tested and installed, so treat marketing figures cautiously and ask for the manufacturer's test method. We do not quote a number here.
They are not a substitute for efficient glass or for sealing air leaks. A cellular shade is an interior covering, so it helps with heat after the sun has passed the glass, as covered in the heat gain guide. For the strongest summer heat control, exterior shading is generally more effective.
Gaps at the sides, top and bottom reduce performance. Side tracks, a snug inside mount and a well-measured size all help. Use the measuring guide to get the fit right.
Look at the whole window, not only the glass. Heat also moves through the frame, and a shade will not fix a leaky frame. Weatherstripping and caulk around the frame can make a bigger difference to comfort than a covering in some homes, so deal with drafts first.
Single-cell shades are slimmer and lighter, and double-cell shades hold more air but are bulkier when raised. Which is best depends on the depth of your window frame and how much you want the shade to do. Check the headrail and stack height before you buy.
Light-filtering fabrics glow softly and give daytime privacy, and blackout versions add a liner that blocks light. For bedrooms, the blackout type pairs well with the advice in the bedroom shade guide.
Stack height is the pile of fabric left at the top when the shade is raised. A tall stack covers part of the window glass even when the shade is open, which can matter for a view or for a small window. Compare stack heights across the products you are considering.
Cordless lifts are common on cellular shades, which suits child-safe homes, and motors are available on many models. See the child safety guide and motorized and smart shades.
Cleaning needs care because many cellular shades should not be soaked. Dust gently and follow the manufacturer's directions, as covered in the cleaning guide.
Condensation is worth a mention. A tight shade can trap cold air against glass in winter, and in a humid room that can lead to moisture on the window. Keep an eye on windows after you install new shades, and open the shades during the day if you see moisture.
Choose cellular shades if you want a soft, tailored look, some insulating value and a stack that stays out of the way. Choose something else if you want a wide view through the shade, as a solar fabric provides, or if you need strong outdoor heat control.
Ask for fabric samples and the maker's performance information. Sun Shades Pro confirms product availability during a consultation and will not make unsupported savings claims about any shade.
Ask for the cell size, the number of layers, the fabric opacity, the stack height and the lift system. Ask whether the shade can be top-down, bottom-up, cordless or motorized. Ask what the manufacturer says about care.
Ask how the fit is handled at the sides. Some systems use side tracks, and some use a snug mount with small gaps. The answer influences both light control and insulation, and it is worth a question before you decide.
Finally, be skeptical of savings claims. Energy use depends on the climate, the house and the habits of the people in it, and no honest seller can promise a number without knowing those things.
Finally, think about how the shade will be used. An insulating shade only works when it is down, so a shade that is awkward to operate will end up raised all day. Cordless lifts, wands and motors make daily use easier, and that practical convenience often decides how much benefit a household actually gets from the product.
Samples help here as well. Compare cell sizes and fabric colors in your own window, since the same shade can look quite different against your walls than it does in a catalog photograph or on a screen.
Their air pockets slow heat transfer, and a snug fit helps. The size of the benefit depends on the product and installation, so ask the maker for test information.
They can help by adding a layer at the window, but exterior shading is generally more effective at blocking solar heat.
Double-cell shades have two layers of air pockets and are bulkier, and single-cell shades have one layer and are slimmer.
Yes. Cordless lifts are common, and motorized options exist on many models.
Tell us which kind of shade you are considering and we will reply about measuring and options.