Dual fuel- Propane and electric

TaskPro

Wanted to get opinion from you guys/gals on dual fuel in NH. Propane system with heat pump above 40 degrees. Would be a split system with a coil in the cabinet. These systems are common in NC and SC but didn't know if people have had good experiences in colder climates.

JUGHNE

Fairly common in Nebr., a little less than 7000 HDD. -5 to -7 degree design day.
Some even can switch over at 35 OAT. I would avoid having to go thru defrost cycle if at all possible.

Hot_water_fan

Pretty vanilla setup, the propane can provide emergency backup, but in terms of economics, propane doesn't compete well vs. a heat pump. A cold climate heat pump can output until the negative teens.

Not sure the exact rates you're facing, but at $4/gallon vs. $.20/kwh, a heat pump is 50% cheaper.



Edit: whoops! Plugged in an oil number. If propane is $3/gallon, you’re 25% cheaper using electricity.

hot_rod

Space-Pak is releasing a 4ton ILAHP. Inverter Low Ambient Heat Pump, air to water.

the spec looks like thie, 120F swt, 17F ambient, 36,903 btu/hr, COP of 1.82. temperature range down to -22F

You can run fan coil at 120F or a bit lower with careful diffuser selection and placement.
Similar to how mini splits keep that discharge up high.

Low temperature radiant is ideal and can use a wider reset range.

A few idronics issue with some ideas.