Most people think their hard hot tub cover is enough to hold onto heat. In reality, heat escapes through the water surface like steam from an open tea kettle.
Adding one of the Best Thermal Blankets for Hot Tub options directly onto the water surface acts as a critical vapor barrier. It keeps the warmth inside and stops your heater from running overtime. Let’s look at why these simple mats are such a smart investment for your utility bill.
Key Takeaways
- Prioritize a thickness of at least 16 mil to ensure the material stays durable enough to withstand constant moisture.
- Check your exact hot tub dimensions because you can easily trim these bubble covers with household scissors for a custom fit.
- Choose closed cell foam options if you want a firmer barrier that feels less like plastic wrap and more like a permanent seal.
- Ensure the material is treated for UV resistance to prevent it from cracking or flaking after months in the sun.
- Look for grey or neutral colors if you want the cover to blend in visually with your surrounding patio aesthetic.
| Top Overall Choice |  |
AllAreN 7×7 Square Bubble Cover | Exceptional heat retention | Perfect square fit | Lightweight design | View on Amazon | Read Review |
| Most Durable Bubble |  |
16-Mil Heavy-Duty Bubble Cover | Highly durable construction | Resistant to chemicals | Easy to customize | View on Amazon | Read Review |
| Best For Inflatables |  |
Hot Tub 16-Mil Floating Blanket | Ideal for inflatable spas | Strong thermal insulation | Easy to store | View on Amazon | Read Review |
| Aesthetic Heat Shield |  |
Gray 16-Mil Square Solar Cover | Stylish gray color | Effective heat trapping | Thick 16-mil material | View on Amazon | Read Review |
| Best Foam Insulation |  |
Closed Cell Foam Spa Blanket | Superior foam density | Very long lifespan | Excellent cold weather protection | View on Amazon | Read Review |
| Top Energy Saver |  |
16-Mil Floating Spa Cover | Increases energy efficiency | Simple, flexible material | Fast heat retention | View on Amazon | Read Review |
| Reliable Daily Performer | BigXwell Square Solar Blanket | Heavy-duty build | Keeps heat contained | Standardized dimensions | View on Amazon | Read Review | |
| Best Rectangular Fit |  |
Blue Wave Rectangular Spa Cover | Unique rectangular dimensions | Blocks debris effectively | Customizable size | View on Amazon | Read Review |
| Best Exterior Shield |  |
Side-Insulated Spa Protector | Protects against snow | Waterproof fabric | Full side coverage | View on Amazon | Read Review |
| Great Versatility Pick |  |
TOPZEA 16-Mil Bubble Cover | Thick bubble material | Good for indoor use | Reliable heat retention | View on Amazon | Read Review |
More Details on Our Top Picks
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AllAreN 7×7 Square Bubble Cover
This bubble cover is the gold standard for those who want a straightforward thermal barrier. It fits standard square tubs perfectly and creates a solid vapor barrier to stop heat loss in its tracks.
It is ideal for anyone who prioritizes thermal efficiency above all else. Just keep in mind that the bubble material is lightweight, so you will want to handle it gently to avoid tears when folding it away.
- Brand:AllAreN
- Cover Type:Bubble solar cover
- Dimensions:7×7 feet
- Additional Feature:Creates vapor barrier
- Additional Feature:Reduces water evaporation
- Additional Feature:Simple floating design
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16-Mil Heavy-Duty Bubble Cover
If you find that standard covers rip too easily, this 16-mil thick blanket offers the extra backbone you need. The added thickness makes it more resistant to the harsh environment of a chemically treated hot tub.
It works best for users who prefer a heavy-duty material that stays intact season after season. You can easily trim the edges with a standard pair of scissors if your tub has rounded corners or unique dimensions.
- Brand:Generic
- Cover Type:Bubble solar cover
- Dimensions:7×7 feet
- Material Thickness:16-mil
- Additional Feature:Prevents water evaporation
- Additional Feature:Simple trim-to-fit sizing
- Additional Feature:Cleans with minimal effort
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Hot Tub 16-Mil Floating Blanket
This blanket is specifically engineered to sit right on the surface, making it an excellent companion for inflatable spas. It helps maintain warmth in smaller water volumes where heat loss happens rapidly.
You will appreciate how it reduces the load on your tub heater during the cooler months. Just be aware that because it is a floating design, you will need to lift it out entirely before hopping in for a soak.
- Brand:Generic
- Cover Type:Floating bubble cover
- Dimensions:7×7 feet
- Material Thickness:16-mil
- Additional Feature:Retains heat efficiently
- Additional Feature:Durable bubble construction
- Additional Feature:Works for stock tanks
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Gray 16-Mil Square Solar Cover
Most covers are blue, but this gray version offers a more subtle look that blends in better with modern patio furniture. It functions just like a classic solar blanket, trapping the sun’s energy to keep your water temp high.
It is a great choice if you want to maintain heat without having a neon blue eyesore in your backyard. The material is thick enough to handle daily use without breaking down prematurely.
- Brand:Generic
- Cover Type:Solar bubble cover
- Dimensions:7×7 feet
- Material Thickness:16-mil
- Color:Gray
- Additional Feature:Floating insulation layer
- Additional Feature:Protects against debris
- Additional Feature:Reflects solar heat
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Closed Cell Foam Spa Blanket
If you dislike the feel of plastic bubble sheets, this closed cell foam blanket is your best bet. It is much denser and provides a more substantial barrier against the cold air, acting like a thick quilt for your tub.
This is a premium pick for extreme winter conditions where you need maximum insulation value. Because it is foam, it does not have bubbles that can pop, making it very long-lasting.
- Brand:Generic
- Cover Type:Closed cell foam
- Dimensions:6×6 feet
- Material Thickness:3/8 inch
- Color:Cream
- Additional Feature:Water resistant foam
- Additional Feature:Floating thermal barrier
- Additional Feature:Durable outer surface
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16-Mil Floating Spa Cover
Energy efficiency is the primary goal here, and this 16-mil cover hits the mark by sealing in the heat. By creating a tight seal on the water surface, it stops evaporation that would otherwise cool your tub down quickly.
It is best for people who want to lower electricity costs by keeping the water at a stable temperature. The material is flexible and folds down into a small footprint when not in use.
- Brand:Generic
- Cover Type:Bubble cover
- Dimensions:7×7 feet
- Material Thickness:16-mil
- Additional Feature:Square cut for spas
- Additional Feature:Minimizes water loss
- Additional Feature:Easy to deploy
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BigXwell Square Solar Blanket
This is a no-frills, heavy-duty blanket that does exactly what it promises. It uses the standard bubble design to float on your water and act as a thermal wall against the outside chill.
It is a solid option for those who want a dependable cover that handles daily removal and replacement without fuss. The material is thick enough to resist minor wear and tear from constant handling.
- Brand:BigXwell
- Cover Type:Bubble solar cover
- Dimensions:7×7 feet
- Material Thickness:16-mil
- Additional Feature:Heat-retaining thermal layer
- Additional Feature:Protects from dust
- Additional Feature:Simple floating design
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Blue Wave Rectangular Spa Cover
Not every hot tub is a perfect square, which makes this rectangular cover a lifesaver for specific models. It offers the same benefits as bubble covers, like heat retention and debris blocking, in a shape that fits wider spas.
The royal blue finish is the industry classic for a reason, as it looks clean and professional. You can easily cut this material with scissors if you need to adjust it for speakers or control panels.
- Brand:Blue Wave
- Cover Type:Rectangular bubble cover
- Dimensions:7×8 feet
- Material Thickness:12-mil
- Color:Royal Blue
- Additional Feature:Reduces evaporation
- Additional Feature:Durable cut-to-fit design
- Additional Feature:Traps heat efficiently
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Side-Insulated Spa Protector
Unlike the floating blankets, this is a wraparound protector that sits on the outside of your hot tub cabinet. It shields the sides from freezing wind and snow, which is a massive help for keeping the internal shell warm.
This is the right choice if you are dealing with severe winter weather and need a secondary layer of defense. It is waterproof, so you do not have to worry about moisture soaking into the insulation.
- Brand:Generic
- Cover Type:Exterior side cover
- Dimensions:94x94x35 inches
- Additional Feature:UV ray protection
- Additional Feature:Shields from dust
- Additional Feature:Winter weather ready
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TOPZEA 16-Mil Bubble Cover
This bubble cover is designed to be highly adaptable for both indoor and outdoor hot tubs. It provides a thick, 16-mil barrier that keeps the water temperature consistent even when the ambient air shifts.
It is a smart pick for anyone who needs a versatile solution for a square spa. The bubbles are well-sealed, ensuring the blanket stays buoyant and effective for a long time.
- Brand:TOPZEA
- Cover Type:Bubble solar cover
- Dimensions:7×7 feet
- Material Thickness:16-mil
- Additional Feature:Heavy duty construction
- Additional Feature:Floats on water
- Additional Feature:Easy to cut/size
Frequently Asked Questions
Do I need a thermal blanket if I already have a hard cover?
A hard cover does most of the heavy lifting, but a thermal blanket provides an extra layer of insulation directly on the water surface. This helps reduce heat loss through evaporation, which is the primary way your tub loses energy. It serves as a cost-effective supplement to your existing equipment.
Can I leave the blanket on while the hot tub jets are running?
You should remove the blanket before turning on the jets. The water turbulence can cause the blanket to flip, tangle, or even get caught in the intake filters. It is designed to sit on still water, so take it off to ensure proper water circulation.
How do I clean my thermal blanket?
Rinse it off with a garden hose every few weeks to remove debris and chemical buildup. If you notice algae or grime, use a soft cloth and a mild soap solution to scrub the surface. Avoid using harsh brushes that might tear the foam or ruin the reflective finish.
Does the shiny side of the blanket go up or down?
You should place the reflective side facing down toward the water. This design bounces the infrared heat back into the tub rather than letting it soak into the blanket material. Following this orientation maximizes the thermal efficiency of your setup.
Will a thermal blanket stop my hot tub water from evaporating?
It acts like a physical barrier that prevents moisture from escaping into the air. By keeping the humidity trapped between the water and the blanket, you will notice significantly less water loss over time. This also helps keep your chemical levels more consistent since you are refilling the tub less often.
