Dual Fuel Hybrid Systems – Best of Furnace + Heat Pump
Automatic switching: Heat pump for efficiency (above 30°F), oil/gas furnace backup for extreme NH winters. Max comfort, max savings.
Authorized Mitsubishi Elite Diamond Contractor – The Highest Level of Excellence.

Dual Fuel vs Single Systems – NH Performance
Having an optimally operating heating and air conditioning system is crucial to building a pleasant and healthy home.
Custom Climates is here to provide you with the utmost satisfaction in terms of our dynamic equipment and services. With the goal of offering 24/7 emergency service, we provide versatile heating and cooling solutions, positioning us among the top companies in New Hampshire.
Our modern diagnostic tools enable us to quickly identify the cause of malfunctions in your HVAC system.

| System Type | Mild Weather (30°F+) | Extreme Cold (-5°F) | Annual Cost (3,000 sq ft) |
|---|---|---|---|
| Furnace Only | 90% Efficient | 90% Efficient | $3,200 (Oil) |
| Heat Pump Only | 400% Efficient | 50% or Offline | $2,100 |
| Dual Fuel Hybrid | 400% Efficient | 90% Efficient | $1,680 |
Key Advantage: Uses heat pump 75% of NH heating season, furnace 25% extreme cold.
How Dual Fuel Hybrid Systems Work
4-Season Operation:
Dual Fuel Benefits for NH Homes
| Benefit | Impact | NH-Specific Value |
|---|---|---|
| Energy Savings | 45% vs oil alone | $1,520 annual savings |
| Reliability | Never fails in extreme cold | NH -13°F design temp |
| Comfort | Steady temps year-round | No defrost interruptions |
| Flexibility | Uses existing oil tank | No fuel conversion needed |
| Space Savings | Single system replaces 2 | Basement/closet friendly |
Seamless Switchover Process
Smart Thermostat Control:
- Wi-Fi Monitoring → App tracks fuel usage + efficiency
- Outdoor Sensor monitors real-time temperature
- 30-Second Switch → No comfort interruption
- Annual Maintenance → Single service call covers both
Compatible Equipment Matrix
| Heat Pump Brand | Oil Furnace | Propane Furnace | Natural Gas |
|---|---|---|---|
| Daikin | Conforto | Pensotti | ✓ |
| Mitsubishi | Conforto | Pensotti | ✓ |
| Trane | ✓ | ✓ | Trane |
Epsom’s Dual Fuel Hybrid Specialists
45% Energy Savings – Seamless Switchover – NATE Certified













