Thermoast:
High-End Innovation
One system for premium home climate—redesigned thermostat
+ app with clearer schedules, smarter interactions,
and sleep-aware comfort.
Prototype
Design system
Output
Role
Lead UX
Designer
Product Design
UI/UX
Interaction Innovation
OverFlow
We redesigned Thermoast into a consistent scheduling experience that users can act on instantly.
Through 9 iterations, we transformed insights into
40+ design assets and improved
user confidence end-to-end.
The final prototype scored 7+ satisfaction and strengthened the business path for retention and premium growth.
As Design Lead, I drove the schedule overhaul and built the innovation modules end-to-end. I aligned direction with a design partner through critique loops, and partnered with PMs to turn requirements into crisp, user-centric decisions.
14% of U.S. households use a smart
thermostat today.
25% of them choose Google Nest.
Google Nest With four generations
since 2011 and ~15M U.S. households,
User they want to seek:
•Streamlined Flow
•Minimal Steps
Simplicity
Aesthetics
Simple UI
Visual Clarity
Modern, Elegant Design
Comfortable & Quality
Clear Temperature System
Reliable Performance
Tactile Clarity
Focus on health
Product Constraints
The redesign was constrained by the physical characteristics
of the Nest Thermostat hardware:
2.0" Round Screen: Prioritizing "glanceable" content over data density.
Rotary & Push Input: Linear navigation via a physical ring and button.
Integrated Sensors: Using proximity/light for "hands-free" automated UI.
Zero-Cost Solution: 100% software-driven; no hardware modifications.
Nest Therm.
320 x 320 CSS px
480 x 480 px @1.5x
Only 2 physical inputs on thermoastat
(No touchscreen / No swipe)
Rotate
Knob
Press
In a U.S. survey of 2,000 adults, 31% said being too hot or cold disrupts sleep
—explaining why people may keep adjusting the thermostat
at night yet still not know what helped.
The Problem
40% - 70%
Users skip scheduling interfaces
because they’re cumbersome.
Goal
From Outdated Visuals → To Modern Clarity
From Fragmented Touchpoints → To Unified Experience
From Complex Controls → To Effortless Actions
From Sleep Guesswork → To Sleep-Aware Comfort
Sleep apps provide metrics but don’t let users control the environment.
Thermoast unifies sleep stages and temperature in a single timeline, highlighting a personal comfort range for the next night.
Thermostats provide control but don’t explain how nightly temperature patterns relate to sleep outcomes.
Opportunity
A refined style appeals to users who seek elegant, distinctive design
Premium Data Legibility
The color scheme meets WCAG’s 3:1 non-text contrast ratio.
Accessibility-ready typography with min/max text sizes for clear, inclusive readability.
The Solution
Review and adjust seamlessly
Clear Access
Switch between Daily and Weekly review easily
Effortless Temperature Tuning
Change temperature easily
And easy to back and edit
Schedule Page
Intuitive interaction, just drag
your finger to modify the time
and temperature
Or edit or delete instantly in place
Sleep Temp Page
Links sleep stages with temperature for quick, easy review.
Google owns sleep signals (Fitbit/Pixel/Nest Hub)
+ climate control (Nest/Thermoast):
measure → visualize → suggest → optionally adjust.
Near-zero marginal rollout via Google Home/Android, amplified by Pixel + Fitbit;
~1/3–1/2 of smartwatch owners track sleep
Scale & channels
Closed-loop advantage
Brand responsibility
Expands Nest from energy-saving to nightly comfort at societal scale.
Ecosystem reach
Tens of millions of sleep-capable devices + Google Home’s 800M+ connected-device footprint.
For sleep & Temperature
Strategic Fit: Why Google / Why now
For the Temp × Sleep feature,
the business upside is twofold:
Premium differentiation:
Strengthens the Pro / high-end
positioning with a clearer story
Engagement → monetization:
User more frequent opens for sleep analysis create opportunities for contextual promotion and traffic-based monetization
(e.g., recommending Thermoast-related upgrades or services in the sleep experience APP).
For the full project, please visit:
https://www.figma.com/design/vphSohyhK2ntiOiaiGvrRQ/%E4%BD%9C%E5%93%81%E9%9B%86%E9%A1%B9%E7%9B%AE%E4%B8%80?node-id=0-1&t=VKufScKwBrDgtLh3-1
Iterated refinement drove
Task efficiency
Product innovation
Visual system coherence
—extending product longevity.
Next step:
Larger test sample / Long-term sleep data / Privacy and permissions challenge
See more detail:
Comparison before and after
Before
Weak visual feedback and Unclear temperature scale
The schedule page is confusing and hard to understand
Unstructured bubbles in landscape mode make the schedule hard to read and edit
After
Dynamic arc with clear, real-time temperature feedback
The new schedule is clear, structured, and easy to understand
Portrait layout offers clearer alignment and easier adjustments
Refining and improving the thermostat through 9 design versions
Applying Insights Through Iteration