insights
insights
“Most people think blinds are about light and privacy. They are. But the right blind on the right window is also a thermal barrier. I have seen clients drop their heater usage noticeably after fitting honeycomb blinds in just three rooms.”Duncan Kane Founder, Custom Blinds Shutters & Awnings
The weakest thermal point in any home. The US Department of Energy puts up to 30% of a home’s heating energy leaving through the windows, and most South African homes have single-pane glass with no double glazing. A blind cannot replace insulated walls, but it sits exactly where the most energy is lost.
Hexagonal cells trap pockets of still air between glass and room. Still air resists conduction and convection, which is what makes it one of nature’s best insulators.
46% less winter heat loss, 78% less summer heat absorption, potential annual energy savings up to 12% (Coulisse, in line with US DOE and Oak Ridge research). A DOE field study at Oak Ridge measured up to 24% heating-energy savings.
Costs more than a roller. Passive after that: every day, no maintenance, no electricity, no moving parts. Cordless and quiet for nurseries.
A tight inside-recess installation leaves the warm air nowhere to travel around the edges. That is where the figure is earned.
Heat-loss reduction, side gaps and budget, side by side.
| Performance | Honeycomb | Duo roller | Blockout roller | Zebra | Wooden venetian | Aluminium venetian |
|---|---|---|---|---|---|---|
| Heat-loss reduction | Highest of any blind | High, double layer | Moderate, dense fabric | Moderate, double-layer fabric | Low to moderate | Low, metal conducts cold |
| Side gaps | Minimal, inside mount | Small hardware gaps | Small hardware gaps | Small hardware gaps | Gaps between slats | Gaps between slats |
| Budget | Higher | Mid-range | Most affordable | Mid-range | Higher | Most affordable |
| Best for | Maximum insulation, nurseries | All-round, day and night | Budget insulation, bedrooms | Living rooms, continuous adjustment | Looks plus some insulation, dry rooms | Light control and wet rooms, not insulation |
Dots show how well each performs on that row; three dots best. The last row is words only.
The budget entry point, or the step up.
Blockout
Most affordable insulator
Duo
Sheer plus blockout
05 The fit decides it
A loosely mounted blind with gaps at the edges lets warm air circulate behind the fabric and escape. A properly measured inside mount sits close to the glass and traps a still layer of air, which is the insulation. Width at three points, use the narrowest; drop at three points, use the longest; millimetres. Custom Blinds Shutters & Awnings makes the recess deductions for you, and the Custom Fit Guarantee covers the sizes you send: too big, trimmed free; too small, remade at a reduced price.
HabitsClose east-facing blinds in the morning and west-facing in the afternoon. In winter, open north-facing blinds by day for free solar heat, and close them before sunset to keep it.
Honeycomb. Coulisse testing, in line with US Department of Energy and Oak Ridge research, shows 46% less winter heat loss and 78% less summer heat absorption. Custom Blinds Shutters & Awnings delivers honeycomb blinds free nationwide.
Yes, at the window, where most heat is lost. They cannot replace insulation or double glazing, but a well-fitted honeycomb or blockout blind reduces the load on heating and cooling every day it is fitted.
No. Metal conducts cold and the slats leave gaps. They are the right blind for light control and wet rooms, not for insulation.
Yes. No-drill tension brackets carry the same fabrics and insulate the same as standard blinds, with no wall damage for renters.
A US Department of Energy field study at Oak Ridge measured up to 24% heating-energy savings from cellular shades. Your figure depends on window count, orientation and how you heat and cool.
Yes. Two fabrics on one bracket make two air pockets instead of one, and you keep daytime light without giving up night-time darkness.
Content reviewed by the Custom Blinds Shutters & Awnings team. Visit the online shop for current pricing.
Custom Blinds Shutters & Awnings | South Africa’s trusted blinds, shutters and awnings specialists since 2010.