How the database works

Methodology

One outdoor unit, many combinations

A heat-pump outdoor unit can be certified with many indoor coils, air handlers or furnaces. Those combinations can have different SEER2, HSPF2 and performance at 5°F. We therefore use one canonical outdoor model page with a combination table rather than selecting one row and applying it to the entire product.

Official-list joins

Massachusetts, Wisconsin, Connecticut and Maine publish qualified-product lists keyed by AHRI Certified Reference Number. That number is the primary join to a complete system combination. California programs can instead require the ENERGY STAR model identifier, so both identifiers are retained.

What “listed” means

“Listed as eligible” means the exact combination appeared on the program-owned product list as of the stated source date. It does not mean the home, applicant, installer or project qualifies, and it never implies a particular rebate dollar amount.

Installed-cost summaries

Cost records come from public program administrators that processed project documentation. Pages show the original dollars, median and mean, sample size, location and coverage years. Missing regions remain missing; a national average is never substituted.

Indexing tiers

All source records are ingested. The best 600–850 model, program and cost pages are indexable at launch. Deeper pages render but remain out of sitemaps and carry noindex until search-console evidence supports promotion.