Field notes
What our engineers write down.
Every article here starts as a technician's field notebook, then gets reviewed by a PE before it's published.
Guide8 min read · Jun 2026
The right-sized furnace: why bigger is almost always worse
Oversized furnaces short-cycle, waste fuel, and shorten every component's life. Here's how we size ours.
By Elena Ostrowski, PE
Research12 min read · May 2026
Cold-climate heat pumps at -22°F: what actually works
We ran three inverter-driven heat pumps through a Duluth winter. Two exceeded rated capacity. One didn't.
By Marcus Rehnquist
Air Quality6 min read · Mar 2026
Why your winter air is 12% humidity — and what to do
Dry skin, static shocks, and wood floors that pop overnight are all a humidity problem.
By Priya Anand
Commercial14 min read · Jan 2026
VRF vs. rooftop packaged: a five-year ROI teardown
For a 40,000 sq ft office, VRF paid back in year four. For a 6,000 sq ft strip retail, it never did.
By Marcus Rehnquist
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