Learn
Understand the numbers before you spend
An HVAC system is a five-figure, fifteen-year decision made under pressure — usually when the old one just died. These guides give you the vocabulary to make it well.
Methodology & the Verified Label Live
Where every number comes from, how we compute $/MMBtu, and what we refuse to do.
What MERV rating do I need? Live
MERV 8 vs 11 vs 13, the MERV/MPR/FPR cross-map, the airflow tradeoff, and a size chart.
Rebadged HVAC brands: when "different" brands are the same machine Live
The biggest rebadge families in our corpus, computed from certified specs — plus who really owns whom, cited.
SEER2, HSPF2 & COP at 5°F, explained Live
What each rating measures, and why COP at 5°F is the cold-climate number that matters.
Heat pump vs. gas furnace Coming soon
The honest cost + comfort comparison at your energy prices.
Most reliable HVAC brands / brands to avoid Coming soon
The distrust query, answered with data instead of ads.
R-454B, R-32 & the R-410A phase-down Coming soon
What the 2025 refrigerant transition means for what you buy.
Guides are written by Erin Rose and grounded in the same certified dataset behind the rest of the site. See our methodology.