Ergonomics Journal
Thermal Microclimate and Humidity Regulation in Viscoelastic Bedding
Ergonomics Research
Casper vs Nectar: Heat Retention & Sagging
All-foam bed-in-a-box comparison: Casper's 3-zone open-cell polyfoam vs Nectar's dense gel memory foam, thermal conductivity, and softening rates.
Casper Sleeps Cooler; Nectar Conforms Deeper
Direct answer summary
The Casper Original and Nectar Memory Foam are the two defining all-foam mattresses in direct-to-consumer bedding. Casper utilizes open-cell AirScape polyfoam over a 3-zoned support core (firmer under hips, softer under shoulders), sleeping significantly cooler and responding faster to movement. Nectar utilizes dense traditional gel-infused viscoelastic foam, providing deeper contouring and superior motion deadening, but retaining more body heat and softening more rapidly under continuous pelvic load.
Key points
Casper uses perforated AirScape open-cell foam with 3-zoned ergonomic cutouts.
Nectar uses dense traditional gel memory foam with deeper contouring and higher heat retention.
Casper sleeps cooler and turns easier; Nectar offers deeper pressure point cradling.
Interactive example
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3D Layer-Peel Visualizer
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Interactive Exploded Architecture & Layer Inspection
Peel through the physical mattress assembly to audit coil gauge, foam density (PCF), indentation load deflection (ILD), and flame barrier composition.
What's insideDrawing only, layer order not confirmed
Casper AirScape vs Nectar Gel Memory layers
Height: 11.00"
Layers: 3 Layers
1/3
All
Active Layer: Top Breathable Layer
2" (COMFORT)Thickness: 2"Material: AirScape Perforated Foam vs Gel Memory FoamDensity: 3 pcf🔥 Conductive Thermal Dissipation
Layers, top to bottom (3)
Click to expand specsHigh-airflow open cell vs dense viscoelastic foam
Thickness2 inches18.2% of stack
MaterialAirScape Perforated Foam vs Gel Memory Foam
Foam Density3 pcfStandard density
Contoured pelvic support (Casper)
Thickness2 inches18.2% of stack
Material3-Zone Polyfoam Core
Foam Density2 pcfStandard density
Standard all-foam structural foundation
Thickness7 inches63.6% of stack
MaterialHigh-Density Base Polyfoam
Foam Density1.8 pcfStandard density
Specifications
Recorded specifications
Values and benchmarks recorded for this question.
| Specification | Measured value | Benchmark | Status |
|---|---|---|---|
| Surface Thermal Dissipation | Casper AirScape Perforations Dissipate +28% Heat | Cooler Sleep Microclimate | pass |
| Pelvic Sinking Rate (Thermal Creep) | Nectar Exhibits 32% More Nighttime Sinkage | Viscoelastic Softening | warning |
| Ergonomic Zoned Support | Casper: 3 Ergonomic Zones; Nectar: Unzoned Flat Foam | Zoned Spine Alignment | pass |
| Trial & Warranty Terms | Casper: 100 Nights / 10 Yrs; Nectar: 365 Nights / Lifetime | Nectar Offers Longer Marketing Policy | pass |
Standards reference: Benchmarks derived from ASTM D3574 (flexible cellular foam), CPSC 16 CFR 1633 (open flame flammability), and clinical capillary closing thresholds (32.0 mmHg).
Checklist
Comparative Spec Verification Checklist
Step-by-step inspection to detect mid-production substitutions and compare component specs.
- 01
Evaluate Body Heat Sensitivity
Choose Casper if you sleep warm; perforated AirScape foam allows convective heat escape.
Watch for: Nectar's dense viscoelastic foam traps ambient body warmth against the torso.
- 02
Check Motion Deadening Need
Choose Nectar if you want complete, zero-rebound motion isolation from a restless partner.
Watch for: Casper's buoyant polyfoam has slightly more mechanical recoil.
- 03
Verify Foundation Center Support
Both all-foam mattresses require rigid support with slats <= 3 inches apart.
Watch for: Placing all-foam beds on curved or wide-spaced slats causes instant center sag.
Sources
Sources for this answer
Read the source documents behind the thresholds, measurements, and policy details used here.
View source
ASTM International
Standard Test Methods for Flexible Cellular Materials
ASTM D3574