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RealCostIQ

HVAC & Utilities Calculators

15 free calculators — HVAC systems, insulation, water heaters, ductwork, and humidifiers. Updated for 2026 rebate rules.

15 free calculators
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Heating & Cooling Systems4Ductwork & Insulation5Water & Humidity Systems6

HVAC rebates & incentives in 2026

Federal 25C / 25D tax creditsHeat pump, AC, furnace, insulation, water heater
Ended Dec 31, 2025
HEAR / HEEHRA rebatesIncome-qualifying; state-administered
Up to $8,000
HOMES rebatesState-administered; still active
Varies by state
State & utility rebatesOften stack on HEAR/HOMES
Varies by state
Installed by Dec 31, 2025?Placed in service before the deadline
Claim on 2025 return (Form 5695)

The federal 25C/25D credits were terminated by the One Big Beautiful Bill Act (2025) for systems placed in service after Dec 31, 2025. Look up programs for your state/ZIP at DSIRE (dsireusa.org). Not tax advice.

Heating & Cooling Systems

4

HVAC Installation Cost Calculator

Full HVAC installation by system type, home size, and SEER rating

$5,000–$12,500System type comparisonState/utility rebates

Furnace & AC Replacement Cost Calculator

Furnace and AC replacement with bundle savings and efficiency analysis

$3,000–$12,000Bundle 5-8% savingsState/utility rebates

Central Air Installation Cost Calculator

Central AC by home size, SEER rating, and ductwork condition

$3,500–$8,000Tonnage calculatorSEER2 efficiency

Mini Split Installation Cost Calculator

Ductless mini split costs by zone count, BTU, and brand tier

$2,000–$14,500State/utility rebatesMulti-zone savings

Ductwork & Insulation

5

Ductwork Installation Cost Calculator

New ductwork installation costs by home size and material

$2,000–$8,000Flex/sheet metal/fiberboardZone add-ons

Ductwork Replacement Cost Calculator

Ductwork replacement including removal and asbestos remediation

$3,000–$10,000Asbestos flagPartial vs full

Attic Insulation Cost Calculator

Attic insulation costs with payback period and energy savings

$1,500–$5,500R-value guideState/utility rebates

Attic Insulation Replacement Cost Calculator

Replacement including old insulation removal and remediation

$2,000–$7,000Removal costMold/pest remediation

Blown-In Insulation Cost Calculator

Blown-in costs by material and R-value target

$1,000–$4,000Cellulose/fiberglass/foamDepth calculator

Water & Humidity Systems

6

Water Heater Replacement Cost Calculator

Water heater replacement costs with rebate guidance

$600–$4,500State/utility rebatesTank vs tankless

Water Heater Installation Cost Calculator

New water heater installation with gas line and permit add-ons

$800–$5,000Gas line add-onPermit cost

Water Heater Maintenance Cost Calculator

Annual maintenance costs with 5-year projection

$100–$500/yrAnnual vs deferred5-year projection

Whole House Humidifier Installation Cost Calculator

Whole-house humidifier costs by type and home size

$400–$1,600Bypass/fan-powered/steamHome size guide

Humidifier Maintenance Cost Calculator

Annual humidifier maintenance with urgency assessment

$60–$350/yrUrgency color codePart-by-part

Reverse Osmosis Installation Cost Calculator

RO system installation with bottled water savings comparison

$250–$1,800vs bottled waterCost per gallon

Guides that go with these calculators