HVAC company valuations rest on SDE (Seller's Discretionary Earnings), not EBITDA, because many are owner-operated. Calculate SDE: take total revenue (service revenue, installation, commercial work, emergency calls), subtract cost of goods sold (equipment, refrigerant, parts, subcontractor labor), subtract technician payroll (W-2 techs), subtract vehicle costs (fuel, maintenance, insurance), subtract occupancy (office rent if any), subtract marketing and customer acquisition, then add back owner compensation, personal vehicle use, personal insurance, and one-time expenses. Your SDE is the baseline.

The 2.5x-4.5x SDE range reflects buyer acquisition activity. An HVAC company generating $200K SDE with 40% service agreement revenue, 6 certified technicians, balanced service-install mix, and strong owner transition trades closer to 4x ($800K) than 2.5x ($500K). The same company with 15% service revenue, solo technician, and owner-dependent trades closer to 2.5x-3x ($500-600K). Service agreement percentage creates 1-1.5x multiple variance.

Service agreement revenue is the primary valuation driver. Service agreements create predictable recurring revenue that reduces acquisition risk. A company with 40% service agreement revenue on $500K total revenue generates $200K recurring revenue with estimated 90%+ customer retention (annual renewal rate). This $200K is worth premium multiple because it's essentially "sold" for next year. Buyers specifically model service agreement revenue separately and apply higher multiple (5-6x) to this segment versus transactional revenue (3-4x). Calculate: $200K service agreements × 5.5x = $1.1M plus $300K transactional revenue × 3.5x = $1.05M = $2.15M total valuation. This compounding effect shows how service agreements drive valuation leverage.

Technician team depth multiplies directly into capacity and valuation. Each certified technician represents roughly $75-150K annual revenue depending on efficiency, specialization, and commercial/residential mix. A shop with 5 technicians operating at 80% utilization generates $300-750K revenue base from those technicians. Each additional technician adds $75-150K capacity and supports 0.3x-0.5x valuation multiple uplift. Technician tenure matters: technicians with 3+ year tenure are productivity anchors; those under 2 years are flight risks.

Revenue mix affects EBITDA margins and valuation multiples. Service/maintenance revenue carries 60-75% gross margins because it leverages technician time and existing customer relationships. Installation revenue carries 30-45% margins because equipment costs are high. Emergency service (calls outside normal hours) commands 25-50% price premium and 70-80% margins. Calculate your revenue breakdown explicitly: what percentage is recurring service, transactional service, standard installations, premium installations, commercial work? Aim for: 35% service/maintenance (70% margin) + 35% installation (40% margin) + 25% commercial (45% margin average) + 5% emergency (80% margin) = blended gross margin of 53%, which at 40%+ EBITDA margin is healthy.

Commercial revenue provides counter-cyclical stability. Residential HVAC demand swings 40-50% seasonally and economically; commercial demand swings 15-25%. Build commercial base through: (1) facility manager relationships, (2) commercial contractor relationships, (3) commercial new construction bids. Commercial accounts are contract-based with multi-year relationships and higher customer lifetime value. A company with 40% commercial revenue has significantly more stable revenue stream than 100% residential.

Owner role transition is often overlooked but material. Shops where owner performs 50%+ of technical work face key-person risk; buyer assumes 50%+ revenue loss if owner departs. Transition plan: gradually move owner to sales/management role, train technicians to handle owner's accounts, develop processes that don't depend on owner judgment. In year 3 post-acquisition, owner should be in purely management/sales role. This transition is worth 0.5x-1x multiple uplift in valuation.

Brand reputation and online reviews drive customer acquisition efficiency. HVAC companies with 4.5+ stars and 150+ reviews on Google generate 20-30% lower customer acquisition cost and 15-25% higher close rate on estimates. Build review system: automated text after service completion asking for review, email follow-up, staff incentives for reviews. Buyers value strong online reputation because it improves profitability and reduces marketing expense.

Buyers actively acquiring HVAC companies include large service platforms (Comfort Systems USA, Tradewinds Climate Systems), PE-backed platforms (Rhone, Fortive), and regional consolidators. Their acquisition targets are companies with $150K+ SDE, 35%+ service revenue, 5+ technicians, and owner transition plan documented. Strategic buyers bid 3x-3.5x SDE. PE buyers bid 3.5x-4.5x SDE because they apply operational improvements and multi-location rollup.

Timing matters. Seasonal peaks vary by region: heating-dominant areas peak in winter, cooling-dominant areas peak in summer. Close valuations in off-season using prior full-year data so seasonal variance is normalized. A company showing strong summer/winter numbers might appear overstated.

Regulatory and operational compliance includes EPA Section 608 certification for all techs, state licensing if required, liability insurance, and worker's compensation. Document all certifications and insurance. Compliance gaps trigger discount requests.