A West Valley City customer in a 1998-built two-story home approached us about replacing their aging gas furnace and AC with a heat pump system. Both pieces of equipment were original to the home — 26 years old at the time of inquiry — and the customer was researching options ahead of failure rather than waiting for a winter emergency. They were specifically interested in heat pump options because of the federal 25C tax credit (up to $2,000), potential IRA Home Electrification rebates, and operating cost considerations.
This case study documents the complete heat pump conversion process from initial consultation through commissioning, including the income-qualified IRA rebate application that significantly reduced net customer cost.
Customer Situation
- Home: 1998-built two-story, approximately 2,150 sq ft
- Existing equipment: 80% AFUE Goodman gas furnace, 80,000 BTU input; matching 3-ton R-22 AC; both 26 years old, original installation
- Existing condition: Both pieces operational but aging; AC making unusual compressor noises; furnace had increasing minor service calls
- Customer priorities: Replace before failure (planned vs. emergency), consider heat pump options, maximize available incentives, household income within IRA Home Electrification qualifying range
- Income qualification: Household income within 80% of area median, qualifying for IRA Home Electrification full rebate level
Equipment Selection Discussion
Three options reviewed:
Option 1: Like-for-like gas furnace + AC replacement — $11,500 installed
– 96% AFUE single-stage furnace
– Standard single-stage AC
– Familiar technology, no electrical work needed
– Federal 25C credit: $600 furnace + $600 AC = $1,200 maximum
Option 2: Dual-fuel system (heat pump + gas furnace backup) — $17,200 installed
– Two-stage heat pump primary
– Gas furnace for severe cold backup
– Heat pump efficiency in mild/moderate weather
– Federal 25C credit: $2,000 heat pump + $600 furnace
– Rocky Mountain Power heat pump rebate: $400
– IRA Home Electrification not qualifying (mixed-fuel system)
Option 3: All-electric variable-speed heat pump — $18,800 installed
– Cold-climate variable-speed heat pump
– Auxiliary electric heat strips for severe cold (15kW)
– Eliminates gas service if customer wants
– Federal 25C credit: $2,000
– Rocky Mountain Power heat pump rebate: $400
– IRA Home Electrification rebate: $8,000 maximum (income-qualified household)
Customer selected Option 3 (all-electric variable-speed heat pump). The IRA Home Electrification rebate alone made the all-electric option significantly less expensive than the dual-fuel option after incentives.
Manual J Load Calculation
On-site load calculation:
- Conditioned area: 2,150 sq ft two-story
- Insulation: R-13 walls, R-30 attic (1998 construction)
- Windows: 245 sq ft vinyl double-pane (original)
- Salt Lake design conditions: 14°F heating / 96°F cooling
Manual J results:
– Heating load: 42,000 BTU/h at 14°F design temperature
– Cooling load: 26,800 BTU/h (2.25 tons)
Note: 80,000 BTU furnace being replaced was 90% oversized for actual heating load — common 1990s contractor over-sizing.
Equipment Selected
Trane XV20i 4 ton variable-speed heat pump system:
- Outdoor unit: Trane 4TWV0048 variable-speed heat pump
- Indoor air handler: Trane TAM9 variable-speed
- Heat strips: 15kW backup electric heat
- Smart thermostat: Trane XL824 with proper balance point and staging configuration
- 12-year parts warranty, lifetime compressor warranty (registered)
Selection rationale:
- Variable-speed cold-climate heat pump maintains capacity at 14°F design temperature
- 4-ton sizing covers heating load with reasonable margin; cooling capacity provides modulation across the 2.25-ton actual cooling load
- 15kW heat strips provide auxiliary capacity for severe cold events below design temperature
- Matched system supports proper modulation through communicating control
Electrical Service Verification
Critical step for heat pump conversion — verify electrical service capacity:
- Existing service: 200 amp panel (1998 construction standard)
- Existing load: Approximately 110 amps connected load (calculated)
- New heat pump compressor: 16 amps at 240V
- Auxiliary heat strips: 65 amps at 240V (15kW)
- Total addition with strips operating: 81 amps
- New service load: 110 + 81 = 191 amps (within 200 amp service)
Electrical service capacity adequate without upgrade. Required: new 240V dedicated circuits for heat pump (40 amp) and heat strips (90 amp).
Electrical work performed by licensed electrician under coordinated scheduling.
Installation
Duration: 2 days
Day 1:
– Old equipment removal (R-22 recovery per EPA, gas line capped per plumbing requirements)
– New air handler installation
– Heat strip installation in air handler
– Refrigerant line set installation (R-410A compatible)
– Condensate drainage
– Electrical work (240V circuits, electrical disconnect, equipment connections)
– Smart thermostat installation and basic configuration
Day 2:
– Outdoor unit placement on existing concrete pad (verified pad condition)
– Refrigerant connections with nitrogen purge during brazing
– System evacuation to 425 microns held 30 minutes
– Refrigerant charge by weight per manufacturer specification
– Smart thermostat full configuration (heat pump operation, balance point, staging, communicating system)
– Final commissioning measurements
Commissioning Measurements
Cooling mode test: (outdoor 78°F)
– Suction pressure: 132 psi ✓
– Discharge pressure: 285 psi ✓
– Subcool: 9°F ✓
– Indoor temperature differential: 19°F ✓
– Compressor amp draw (1st stage): 5.8 amps; (full stage): 14.2 amps ✓
Heating mode test: (outdoor 78°F — limited because of mild weather, full testing planned during cold weather follow-up)
– Reverse valve operation: confirmed
– Heat pump heating output: confirmed
– Auxiliary heat strip activation tested independently (proper sequencing confirmed)
– Defrost cycle simulated test: nominal operation
Smart thermostat configuration:
– Equipment type: variable-speed heat pump with auxiliary heat
– Balance point: 25°F (auxiliary heat assists below this temperature)
– Compressor lockout: 5°F (below this, auxiliary heat only)
– Wi-Fi connectivity established for remote monitoring
Cold Weather Follow-Up
Customer scheduled cold-weather follow-up visit in January after first sustained cold spell:
- Outdoor temperature during visit: 11°F
- Heat pump operating in stage 2 (high capacity)
- Auxiliary heat activated as designed below 25°F balance point
- Indoor temperature: 70°F maintained at setpoint
- Heat pump output verified: 31,400 BTU/h at 11°F (manufacturer spec at conditions)
- Aux heat strips delivering additional 51,200 BTU/h (15kW)
- Total system capacity: 82,600 BTU/h at 11°F — well above 42,000 BTU/h design load
Customer reported indoor temperature stable through coldest 2-day cold snap (low of -2°F overnight).
Final Cost and Rebate Filing
Customer’s project cost:
– Equipment and installation: $18,800
– Electrical work (240V circuits, dedicated electrician invoice): $1,650
– Total: $20,450
Rebates and credits filed:
– Federal 25C tax credit: $2,000 (customer claims on tax return)
– Rocky Mountain Power Wattsmart heat pump rebate: $400 (mailed to customer)
– IRA Home Electrification rebate: $8,000 (income-qualified, application processed through state program)
Effective net cost after all incentives: $10,050
The IRA Home Electrification rebate alone reduced effective cost by 39%. Combined with federal credit and utility rebate, total incentives reduced net cost by 49%.
Customer Outcome
Six-month operational data (winter heating season):
– Average winter electric bill: $185/month (heating + base load)
– Prior year comparison (gas furnace + AC): $95 electric + $145 gas = $240/month average
– Net monthly savings: ~$55/month winter
– Indoor comfort consistent across home
– No supplemental heating sources needed
Summer follow-up (subsequent year):
– Variable-speed cooling provides excellent dehumidification
– Stage 1 operation handles most cooling demand quietly and efficiently
– Average summer electric bill: $185/month (cooling + base load)
– Prior year comparison: $215/month with old AC
– Net summer savings: ~$30/month
Total estimated annual savings vs. original equipment: $1,000+/year
What This Case Study Demonstrates
- IRA Home Electrification rebates are real — $8,000 income-qualified rebate fundamentally changes heat pump economics for qualifying households
- Variable-speed cold-climate heat pumps work in Salt Lake winter — 11°F operation confirmed; -2°F overnight handled with auxiliary heat assistance
- Electrical service verification matters — 200-amp service was adequate but required calculation; 100-amp service would have required upgrade
- Documented commissioning across modes — cooling commissioned immediately, heating verified during cold weather follow-up
- Realistic savings expectations — $1,000+/year savings is significant but not the unrealistic claims some marketing makes
- Right equipment for the situation — all-electric variable-speed appropriate for income-qualified customer; dual-fuel might have been better for non-qualifying customer
Considering a Heat Pump Conversion?
If you’re researching heat pump options in West Valley City, contact us or call (385) 250-0687. We perform Manual J load calculations, verify electrical service capacity, model all available incentives (Federal 25C, Rocky Mountain Power Wattsmart, Dominion Energy Therm-Wise, IRA Home Electrification), and provide written quotes with rebate-adjusted net cost analysis.
- Phone: (385) 250-0687
- Address: 4454 Manhattan Ct, West Valley City, UT 84120