Therm-a-Rest Parsec 20 Review (2026)

Name: Therm-a-Rest Parsec 20
Brand: Therm-a-Rest
Price: 370.00 USD
Availability: InStock
Rating: 8.7 (1 reviews)

The Parsec 20 adds Therm-a-Rest's reflective barrier lining inside the hood and footbox, a lightweight reflective material designed to bounce radiant body heat back rather than letting it escape, effectively boosting perceived warmth without the weight cost of additional down fill. Combined with 800 fill power down and a full-length zipper for venting flexibility, it lands as a well-rounded, slightly warmer-feeling bag than its raw fill power and weight numbers alone would suggest.

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$370 retail

8.7

/10

TrailCraft Score

What Works

Reflective barrier lining meaningfully improves perceived warmth in the hood and footbox
Full-length zipper provides good venting flexibility
800 fill power down is a solid mid-premium warmth-to-weight tier
Therm-a-Rest's broad retail availability and reliable warranty support

Limitations

1lb 9oz is heavier than pure ultralight competitors at a similar temp rating
$370 is a mid-premium price without top-tier fill power
Reflective lining adds a small amount of weight versus a simpler design
15D shell fabric still requires reasonably careful handling

Specifications

Fill Power800 fill power down

Weight1 lb 9 oz / 709 g

Temp Rating20°F comfort

ZipperFull-length, dual-slider

HoodAdjustable hood with reflective lining

Shell15D ripstop nylon

WarrantyLimited lifetime

OriginDesigned in USA, made in Vietnam

Score Breakdown

Warmth

8.9

Weight / Compression

9.0

Build Quality

8.8

Value for Money

6.5

Brand & Warranty

8.8

What Sets It Apart

Combined with 800 fill power down and a full-length zipper for venting flexibility, it lands as a well-rounded, slightly warmer-feeling bag than its raw fill power and weight numbers alone would suggest.

1lb 9oz, $370 — reflective barrier lining boosts perceived warmth without adding fill

Who This Is For

The Therm-a-Rest Parsec 20 is right for hikers whose priorities match its design: built around warmth-boosting reflective lining, at 1 lb 9 oz and $370.

A note on pricing and links: Prices listed are current as of July 2026 and may change. Some links on this page are affiliate links — if you buy through them, I earn a small commission at no extra cost to you. It does not change my ranking.

How It Compares

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All options in this category ranked side by side — specs, scores, and pricing.

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Common Questions

What is reflective barrier lining?

A thin reflective material Therm-a-Rest places inside the footbox and hood, designed to reflect radiant body heat back toward the sleeper rather than letting it pass through the insulation and escape, boosting effective warmth without more down.

Does the reflective lining actually make a noticeable difference?

Many users report noticeably warmer feet and head area specifically, the zones where the lining is placed, though it supplements rather than replaces the primary down insulation.

How does the Parsec 20 compare to the Hyperion 20 from the same brand?

The Hyperion 20 is lighter and more minimalist; the Parsec 20 adds the reflective lining and a slightly roomier cut at some weight cost, appealing to hikers who prioritize warmth features over absolute minimum weight.