Case Study: Residential Heat Pump Conversion Along 84th Street Corridor, Ralston
This case study documents a residential heat pump conversion for a Ralston home along the 84th Street corridor (the major north-south arterial bordering Ralston’s western edge). The customers chose to retire a functional gas furnace and AC in favor of cold-climate heat pump primary heating, motivated by interest in electrification and substantial federal tax credit availability. The 1985 split-level home was substantially upgraded with insulation improvements two years prior, making it well-suited for heat pump primary heating with backup electric resistance for extreme cold periods.
Customer Situation
The property is a 1985 split-level home in Ralston west of 84th Street, 1,950 sq ft on a 6,800 sq ft lot with attached two-car garage. The customers (couple in their mid-40s with one teenage child, husband works in renewable energy industry, wife is a high school teacher) had owned the home for 11 years (purchased 2014). They had completed substantial insulation improvements in 2023 including R-49 attic insulation upgrade (from R-19 original), basement wall insulation addition, and attic air sealing — producing a substantially tighter envelope than original 1985 construction.
Existing equipment:
- 2014 Lennox 95% AFUE 80K Btu/hr gas furnace, 11 years old, operating well
- 2014 Lennox 14 SEER R-410A AC, 3 ton, 11 years old, operating well
- Equipment in mid-life with substantial remaining useful service possible
- No equipment failure motivating replacement
Motivations for proactive heat pump conversion:
- Husband’s professional interest in electrification (renewable energy industry career context)
- Environmental commitment to reduce on-site fossil fuel combustion
- Federal Section 25C tax credit ($2,000 cap for qualifying cold-climate heat pumps)
- OPPD heat pump rebate ($1,200 for cold-climate variable-capacity equipment)
- Recent insulation upgrades created tight envelope suitable for heat pump primary heating
- Equipment age (11 years) suitable for proactive replacement before end-of-life
Heat Pump Suitability Analysis
Consultation by Jess Sandoval (Install Lead, 11 years, Manual D specialty). Assessment focused on heat pump suitability given recent envelope improvements.
Updated Home Energy Performance
- 1985 split-level original construction: R-13 walls, R-19 attic, single-pane windows replaced 2018 with thermal-break windows
- 2023 insulation upgrades: R-49 attic, basement wall insulation, attic air sealing
- 200-amp electrical service standard for the era; verified adequate for heat pump and backup heat circuit
- Manual J load calculation post-insulation upgrades: 38,000-42,000 Btu/hr heating, 2 ton cooling
- Original 80K furnace and 3 ton AC were substantially oversized after 2023 upgrades
Cold-Climate Heat Pump Capability for Omaha
- Omaha ASHRAE 99% winter design temperature: -4°F
- Cold-climate heat pumps maintain rated heating capacity to substantially below freezing
- Selected Mitsubishi MXZ-SM48NAMHZ (cold-climate variable-capacity) rated for heating to -13°F
- Electric resistance backup heat handles any brief periods of extreme cold below heat pump capacity
- Historical Omaha cold extremes: 2019 polar vortex -22°F (rare events; brief periods)
Equipment Selection
- Mitsubishi MXZ-SM48NAMHZ outdoor unit — cold-climate variable-capacity inverter, up to 24 SEER2 cooling, 12 HSPF2 heating, rated heating capacity to -13°F, 2 ton size (right-sized to actual load post-insulation upgrades)
- Mitsubishi PEAD-A30AA8 ducted air handler — variable-speed ECM motor matched to heat pump capacity, ducted for existing ductwork integration, 12 kW electric resistance backup heat
- Mitsubishi kumo cloud communicating thermostat — smartphone control, advanced scheduling, smart-home integration
- Existing ductwork retained — already properly sized; no modifications needed
Installation Execution
Standard residential heat pump conversion, single 8-hour day:
- Morning — Equipment delivery. Existing furnace and AC removal (R-410A refrigerant recovered to EPA Section 608 standards; gas line capped). Outdoor heat pump unit installation on existing AC pad with appropriate vibration isolation for variable-capacity equipment.
- Midday — Ducted air handler installation in mechanical room replacing existing furnace location; electric resistance backup heat installation in air handler; refrigerant line set installation (replacing existing R-410A line set with new A2L-compatible line set since current Mitsubishi cold-climate heat pumps use R-454B refrigerant); electrical connections including 12 kW backup heat circuit.
- Afternoon — Mitsubishi kumo cloud thermostat installation and commissioning; smart-home integration setup; system startup and refrigerant charging; performance testing across heating and cooling modes; customer walkthrough.
Results
- Heat pump primary heating — all-electric heating eliminating on-site natural gas combustion
- Cold-climate operation — rated heating capacity to -13°F well below Omaha design conditions
- Right-sized equipment — 2 ton heat pump matched to actual load vs prior 80K furnace + 3 ton AC oversized for current envelope
- Smart-home integration — kumo cloud system integrated with customer’s existing home automation
- Federal Section 25C tax credit — $2,000 (30% × $2,000 cap for qualifying cold-climate heat pump)
- OPPD heat pump rebate — $1,200 for cold-climate variable-capacity equipment
- Customer environmental satisfaction — alignment with broader environmental commitments and husband’s professional perspective
Pricing
Total project cost: $14,200
- Mitsubishi MXZ-SM48NAMHZ cold-climate outdoor unit (2 ton): $5,800
- Mitsubishi PEAD-A30AA8 ducted air handler with 12 kW backup heat: $3,400
- Mitsubishi kumo cloud thermostat: $585
- A2L-compatible refrigerant line set: $585
- Electrical work for backup heat circuit and outdoor unit: $585
- R-410A refrigerant recovery and gas line capping: $285
- Installation labor (8 hours): $2,485
- Smart-home integration: $385
- Materials, supplies, miscellaneous: $91
Net cost after rebates and credits:
- Project cost: $14,200
- OPPD heat pump rebate: -$1,200
- Federal Section 25C tax credit: -$2,000
- Net cost: $11,000
First-Year Operating Performance
- Heating season: heat pump primary for 97% of heating hours (substantial improvement vs typical cold-climate heat pump installations due to tight envelope reducing extreme cold load)
- Total backup heat operation: 14 hours over heating season (substantially less than typical cold-climate heat pump backup usage)
- Cooling season: variable-capacity operation produced longer steady-state cycles with substantially better humidity removal
- Annual operating cost: approximately 6% lower than equivalent gas furnace + AC operation in this tight envelope context
- Customer reported substantial satisfaction with comfort and equipment quiet operation
Why Insulation Upgrades First Matters
This customer’s 2023 insulation upgrades (R-49 attic, basement wall, air sealing) before 2025 heat pump conversion produced substantially better outcomes than heat pump conversion in original-envelope home:
- Heating load reduced from approximately 60,000 Btu/hr (original envelope) to 38,000-42,000 Btu/hr (post-upgrade)
- Right-sized 2 ton heat pump can handle the smaller load effectively
- Reduced backup heat usage during extreme cold (smaller load doesn’t push beyond heat pump capacity as often)
- Lower operating costs (smaller load = lower energy consumption regardless of equipment)
- Lower equipment capital cost (2 ton equipment less expensive than 3 ton)
- Customer received double benefit: lower energy bills from insulation + appropriate equipment sizing for the improved envelope
Lessons from This Project
- Envelope improvements (insulation, air sealing) substantially affect appropriate equipment sizing for heat pump conversion
- Sequencing: insulation upgrades before equipment replacement produces better outcomes than upgrading equipment first
- Cold-climate heat pumps work effectively for Omaha winter conditions when paired with appropriate envelope and backup heat
- Mitsubishi MXZ-SM series provides excellent cold-climate performance with substantial efficiency at moderate cost
- Customer professional context (renewable energy industry) supports informed equipment selection and operational understanding
- Federal Section 25C tax credit + OPPD rebate combination ($3,200 total) substantially reduces qualifying heat pump installation costs
Contact Omaha Heating and Air Conditioning
For Ralston heat pump conversion, electrification consultation, cold-climate equipment installation, or coordination with insulation/envelope upgrades, call our 24/7 line.
- Emergency Line (24/7): (402) 258-6703
- MUD Gas Emergency: 402-554-7777 (suspected gas leaks)
- 911: for CO detector alarms or fire/smoke situations
- Address: Lake Regency Building, 450 Regency Pkwy #370, Omaha, NE 68114
- Email: info@omahaheatingairconditioning.xyz
- City of Omaha Mechanical Contractor License: #MC-2014-08847
- EPA Section 608 Universal: #608U-2014-227841