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 project teams can act on.

Early Design Tooling Building Energy Simulation Workflows Systems Thinking EnergyPlus Python Dashboards

Inspired by SimBuild 2024 · NREL / LBNL / DOE

Smart Thermostat Energy Study

This interactive dashboard demonstrates the kind of analysis from our SimBuild 2024 research — a simplified recreation using the same methodology to show how climate zone shapes the energy-comfort tradeoff. 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.

Building model: single-family home with central AC + gas furnace — EnergyPlus AirflowNetwork example, representing a typical mechanically-conditioned residential building.

How Each Strategy Controls the Building — Daily Heating & Cooling Setpoints (°F)

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. But night setback also increases ASHRAE 55 discomfort hours, sometimes dramatically. This is the real tradeoff a design team needs to quantify by location.

Total Energy Savings (kWh/yr)

Thermal Comfort — ASHRAE 55-2004 Discomfort Hours/yr


Work

Other Projects

🌡️
MegaBOP — Climate-Specific Thermostat Performance
Ran a statistical sample of ResStock residential building models through BOPTEST co-simulation to quantify exactly how much a smart thermostat strategy saves — and whether that answer changes by climate. Savings ranged from 6% in Miami to 21% in San Francisco, driven by whether the annual load is dominated by gas heating or electric cooling.
→ Replaces "10% rule of thumb" guidance with climate-specific numbers a design team can actually write into specs.
BOPTESTModelicaResStockGrafanaDocker
🔧
MOSTCOOL — Data Center Design Decision Tool
Built MOSTCOOL (ARPA-E COOLERCHIPS) from scratch — an integrated platform coupling EnergyPlus, flow network modeling, reliability analysis, and lifecycle cost into a single workflow. Worked directly with facility engineers and company leadership to translate co-simulation outputs into clear dashboards and comparisons across cooling architectures.
→ Enabled cooling system selection based on quantified PUE, downtime risk, and cost — before any equipment was specified.
EnergyPlusHELICSPandaPipesDashboardsARPA-E
🏢
EnergyPlus Core + Scout: Modeling Depth & Workflow Tooling
Contributed HVAC module fixes and features to the EnergyPlus C++ source — the kind of work that builds an intuition for what the engine is actually doing, not just what the output says. Separately, built automated CI infrastructure for DOE's Scout building energy tool: cross-platform testing, regression comparison at 0.0001% tolerance, and automated plot diffs posted directly in PR comments.
→ The simulation workflow tooling translates directly to practice: reproducible runs, automatic regression detection, and results a distributed team can trust across offices.
C++EnergyPlusGitHub ActionsDOE
github.com/jmythms →

Jermy Thomas

Building performance analyst with 6+ years using EnergyPlus to support high-performance design — from early-stage energy studies through detailed analysis. My work at NREL centers on turning simulation workflow outputs into clear, decision-ready information for multidisciplinary teams, government stakeholders, and industry partners.

My analytical focus spans energy modeling, HVAC behavior, thermal envelope performance, thermal comfort, and weather-driven analysis — with a strong emphasis on communicating results as graphics and dashboards that design teams can act on. Co-authored "Simulation-Driven Rating of Smart Thermostats" at SimBuild 2024 (NREL, LBNL, DOE); MS thesis on thermal comfort. Experience includes AMY weather file creation, ASHRAE 55 analysis, HVAC controls and schedule studies, and direct collaboration with industry stakeholders on building performance projects.

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