Bestopedia Rankings

Best HVAC Contractors in Altadena, California

Ranked by the Bestopedia Trust Score, drawn from verified CSLB license, bond, and workers’-comp records. Rankings are earned — never for sale.

Last updated July 5, 2026

Our Top Pick

Grueter Construction Corp

Trust Score 100/100 — CLEAR license standing, bonded, workers’ comp current.

VERIFIED

  1. Grueter Construction Corp

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    100 / 100 Trust Score

  2. Howe Michael D

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    100 / 100 Trust Score

  3. Action Duct Cleaning Company Inc

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    100 / 100 Trust Score

  4. H & H Mechanical Inc

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    100 / 100 Trust Score

  5. Comfort Heating & Cooling Systems

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    100 / 100 Trust Score

  6. Smalling Mechanical Co

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    96 / 100 Trust Score

  7. Simco Mechanical Inc

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    94 / 100 Trust Score

  8. Air Conditioning Solutions Inc

    CLEAR license standing, bonded, workers’ comp not current.

    LISTED
    88 / 100 Trust Score

  9. Prime Air Mechanical Inc

    CLEAR license standing, bonded, workers’ comp current.

    VERIFIED
    83 / 100 Trust Score

noun /best-oh-PEE-dee-uh/

a curated ranking of the best in any category, based on independent review.