Building
Performance
Analyst

How do building systems really behave — and what should a design team do about it?
6+ years turning EnergyPlus simulations into decisions architects can act on.

EnergyPlus OpenStudio Python Thermal Comfort ResStock eQuest Spawn C++

SimBuild 2024 · NREL / LBNL / DOE

Smart Thermostat Energy Study

When a thermostat setback saves energy in Chicago but barely moves the needle in Miami — that's a design decision, not just a number. Same house, same mechanical system, five cities. This study quantifies the energy-comfort tradeoff so building teams can specify thermostat strategies with confidence, not assumptions.

click legend to toggle · double-click chart to reset
FLAT — Annual Total
kWh/yr (elec + gas)
STEPPED — Annual Total
kWh/yr (elec + gas)
Energy Savings
from night setback
Comfort Penalty (flat)
hrs/yr ASHRAE 55-2004 not met

Annual Energy End-Uses

Monthly Gas Heating (kWh)

Hourly HVAC Electricity — Full Year (kWh)


Cross-Climate Analysis

Night Setback Savings by Climate Zone

Same control strategy, very different outcomes. Denver saves 14%, Miami saves 6% — because heating dominates in cold climates and setback cuts gas directly. This informs how a design team should specify thermostat controls for a particular location, not as a one-size rule.

Total Energy Savings (kWh/yr)

Savings Percentage by End-Use


Work

Other Projects

ResStock Data Explorer
DuckDB + HTTPFS over NREL's 550 GB ResStock dataset on AWS S3. Interactive climate zone selector with occupancy-weighted energy profiles — no local download required.
→ Helps design teams benchmark a proposed building against the actual stock in that region.
DuckDBResStockParquetAWS S3
github.com/jmythms2 →
🔧
MOSTCOOL — Data Center Co-Simulation
Built MOSTCOOL (ARPA-E COOLERCHIPS) to predict data center cooling performance under real operating conditions — integrating EnergyPlus, CFD, thermal reliability, and cost into one platform. Led development, coordinated universities and national lab partners.
→ Gave facility teams quantified cooling trade-offs before committing to equipment selection.
EnergyPlusHELICSCFDARPA-E
github.com/jmythms2 →
🏢
EnergyPlus Core + Scout Contributions
100+ commits to the NatLabRockies/EnergyPlus C++ source — HVAC module work, CI/CD pipeline. 12 PRs to DOE's Scout building energy tool: measure adoption modeling and emissions pathway analysis.
→ Working at the source level means fewer modeling surprises when results don't match expectations.
C++EnergyPlusDOECI/CD
github.com/jmythms2 →

Jermy Thomas

Building performance analyst with 6+ years using EnergyPlus and OpenStudio to quantify energy, comfort, and HVAC behavior. My work at NREL bridges rigorous simulation and clear communication — turning model outputs into decisions teams can act on.

Co-authored "Simulation-Driven Rating of Smart Thermostats" at SimBuild 2024 with NREL, LBNL, and DOE. MS thesis on thermal comfort. Experience with AMY weather file creation, ASHRAE 55 comfort analysis, and schedule/controls impact studies.

Other work: data center co-simulation (MOSTCOOL / ARPA-E), ResStock building stock analysis, 2,000+ parallel EnergyPlus runs on HPC at PNNL, eQuest modeling, OpenStudio and Eppy workflows.