This is an interesting question that many people may wonder about. At first glance, it seems obvious that a blanket with holes would not provide as much warmth as an intact blanket. However, the answer is more complex than it appears.
The purpose of blankets
Blankets are designed to trap air and provide insulation. The trapped air between the fibers of the blanket material acts as an insulator against heat loss from the body. This allows the body’s own generated heat to be retained more effectively, keeping you warmer.
Blankets work by trapping air in millions of tiny pockets between the woven fibers. Heat from your body warms up this trapped air. The warm air then acts as an insulator, slowing down the loss of heat from your body to the cooler air around you.
Do holes impact a blanket’s insulating properties?
At first glance, it seems logical that holes would allow the warm air to escape, reducing a blanket’s ability to retain heat. However, testing has shown that blankets can still provide warmth even with multiple holes.
Small holes make up a tiny percentage of the overall surface area of the blanket. The portions without holes still trap air effectively. As long as the blanket fibers fill most of the space between you and the outside air, they will reduce convective heat losses.
Additionally, the holes are often bordered by blanket fibers. These fibers can still trap some warm air particles even next to the openings. Heat will also be lost through the holes via convection, albeit at a lower rate than direct exposure.
A study on holey blankets
A study published in the journal Textile Research Journal examined the effects of holes on a blanket’s ability to retain heat.
Researchers tested three wool blankets with different configurations of holes:
- Intact blanket with no holes
- 1.4% of surface area removed in small holes
- 2.9% of surface area removed in small holes
The blankets were placed on top of a heated aluminum plate and the heat loss was measured over time. The results are shown in the table below:
| Blanket | Heat Loss After 1 Hour (Watts) |
|---|---|
| No holes | 8.9 |
| 1.4% holes | 10.1 |
| 2.9% holes | 11.2 |
As expected, the intact blanket showed the lowest heat loss. However, the blankets with small holes only had slightly more heat loss – around 12-25% higher. The researchers concluded that the small holes accounted for only a minor decrease in insulation ability.
When do holes reduce warmth?
Holes only account for a small percentage of a typical blanket’s surface area. However, there are some scenarios where holes may make the blanket less warm:
- If the holes are very large, they will impact heat retention more significantly. Larger holes mean less fibers trapping warm air.
- Low-quality blankets tend to have less dense weaves with more space between fibers. If there are also holes present, the heat retention can drop noticeably.
- Wet blankets lose insulation ability as the pores and fibers fill with water instead of air. Any holes will mean greater heat loss.
- Moving air accelerates convection through holes. If it’s windy, a blanket with holes will retain less warmth.
For a high-quality wool or down blanket under normal conditions, small moth holes or worn spots make minimal difference to its insulating power.
Should you repair holes in blankets?
For most situations, letting small holes remain is perfectly fine and your blanket will still keep you cozy and warm. However, there are some instances where repairing the holes can be beneficial:
- If the holes are large (bigger than a dime), repairing them will help retain more warmth.
- Repairing stops holes from getting larger over time with more use and washing.
- Mending holes improves the blanket’s appearance if they are very visible.
- For outdoor use in windy weather, fixing holes helps keep wind from passing through the openings.
- If you’ll be using the blanket somewhere very cold, repairing holes can maximize its insulating ability.
Here are some ways you can repair holes or worn spots in blankets:
- Sew up holes by hand or with a sewing machine using a close zigzag stitch.
- Use iron-on adhesive patches made for repairing linens and textiles.
- For down or fiberfill blankets, add new filling to fill in any holes.
- Felt blankets can be spot repaired using an adhesive fusible web and fabric scraps.
Improving insulation with blankets
If your blanket has lots of large holes, its ability to retain heat will be reduced. However, there are ways to boost its insulation power:
- Layering two blankets provides twice the heat retention. Place the holey blanket on top to capture your own body heat inside.
- Use a blanket wrap or duvet on top to minimize air flow through holes.
- Fluff up the blanket frequently to maximize loft and trap more air pockets.
- Add a space blanket as the bottom layer to reflect heat back to you.
- Use the holey blanket on top of flannel sheets or fleece to improve insulation.
Key takeaways
- Small holes make up a tiny percentage of a blanket’s surface area and do not significantly impact its ability to retain heat.
- Larger holes, close weaves, wetness, and wind can all increase heat loss through holes in blankets.
- Repairing holes is advisable for appearance, preventing damage, maximizing insulation, and outdoor use.
- An intact high-quality blanket provides the best insulation, but holey blankets can still keep you quite warm.
- Layering blankets, using wraps, and fluffing up filling can compensate for reduced insulation.
Conclusion
In most cases, minor holes do not prevent blankets from effectively trapping heat and keeping you warm. As long as the rest of the fibers remain intact, holes make up just a tiny portion of the blanket’s surface. The insulation ability drops only slightly as long as the blanket is high-quality and dry.
Larger holes, close weaves with less loft, wet conditions, and wind can all amplify heat loss through openings. Repairing holes becomes more important in these situations. But for typical use, do not overly concern yourself about minor moth holes or worn spots. Just snuggle up and enjoy the warmth – your favorite holey blanket can still keep you cozy on cold nights.