Thermal Curtain Payback Calculator
| Whole-bill slice saved | $100 a month heat bill | $150 a month | $250 a month |
|---|---|---|---|
| 1.5 percent a season | $8 | $11 | $19 |
| 3 percent a season | $15 | $23 | $38 |
| 4.5 percent a season | $23 | $34 | $56 |
Enter the windows you will cover, the panel price, and your slice of the heating bill. The calculator returns the season savings and the payback in winters.
The honest math stacks two DOE numbers: windows let out roughly 25 to 30 percent of heating energy, and tight-weave curtains cut window losses by up to 10 percent. The product is a few percent of the whole bill - real money on a cold zone, and the payback runs a couple of winters, not one. Honeycomb cellular shades do better because their cells trap a layer of still air.
How to use
- Count the glass you actually want covered - north and wind-facing windows first.
- Panel price is per window: tight weave is the spec that matters, the thermal brand name is not.
- Pick the slice honestly: 3 percent is the DOE-derived middle, 1.5 for mild zones, 4.5 for honeycomb in a cold zone. Updates live.
Frequently asked questions
Do thermal curtains actually save money?
A few percent of the heating bill: the honest middle is about 3 percent a season - windows carry 25 to 30 percent of the loss and tight weave cuts window loss up to 10 percent. On a 200-dollar winter month that is roughly 6 dollars a month, and the calculator prices your windows.
How much do thermal curtains cost?
About 25 to 50 dollars per window for a tight-weave panel, more for true cellular honeycomb shades. The payback math cares about the weave and the fit - a panel that seals the sides beats a fancy one that hangs flat an inch off the glass.
Are thermal curtains worth it in summer?
Yes, in sun zones: the same panel blocks solar gain, which is where the summer money hides. The calculator prices the winter half; the summer half is free on the same panels.
What is better, thermal curtains or cellular shades?
Cellular honeycomb shades insulate better because the cells trap still air against the glass - that is the 4.5 percent slice. Curtains win on price and on sealing drafts at the frame when they hang past it. Both beat bare glass by a wide margin.
Should curtains be open or closed in winter?
Closed at night, open on south-facing windows when the sun is out. Night is when the glass is the coldest path out; sunny-day solar gain through south glass is free heat no panel should block.