Heating the home - electric vs. natural gas?

[eatSleepWoof]

My first winter in the OK (Vernon). I've got a "high efficiency split system" heat pump. My understanding is that it can run off of electricity or natural gas. The manual says that I can force the heat pump to run off of the secondary energy source (natural gas) by setting the thermostat to "EM Heat."

Do you find it is more cost effective to heat using natural gas instead of electricity in the winter? Do you run the thermostat in AUTO or EM Heat mode? I can't seem to find when/how the heat pump will fall back to the secondary (natural gas) source if set to AUTO, and am wondering whether it would be better to just set it to EM Heat manually.

[LANDM]

The heat pump works off electrical power.....basically an air heat exchange.....in the winter, it is AC in reverse. It does not operate off gas.
If you choose emergency heat, then it bypasses the heat pump and you only use your gas furnace. With current prices, it is probably better to use the gas furnace once we get down to freezing temps. Heat pumps aren’t inefficient below -4C anyways and I’m sure someone more knowledgeable will hop in here. I have had a heat pump and gas furnace for the past 25 years so it is pretty normal.

[Bpeep]

Gas is cheaper to heat with than a heat pump.
A heat pump is cheaper to run than direct radiant electric.

If you have a gas furnace and an air source heat pump, heat with the gas furnace. On the stat it'll likely be the emerg heat mode so run it just on emerg.

People get sold a bill of goods on heat pumps, especially if they have a gas service .

[TylerM4]

Right now the price of NG is at historic lows. Electricity, not so much.

The cost to operate in heat pump mode (electric) vs alternate heat mode (gas) is probably a wash depending on what your exact rates and efficiencies are.

The alternate heat isn't so much about "emergency" heat. It's due to the fact that air source heat pumps don't operate efficiently in sub-freezing temperatures. Most will switch over to alternate heat at around -5* for this reason.

If I was you, I'd leave your heating system mostly alone EXCEPT I'd adjust the setpoint at which the alternative heat source is used. I'd turn it from it's factroy setpoint of approximately -5* to around 0* for the most cost effective operation.

[WalterWhite]

The heat pump works off electrical power.....basically an air heat exchange.....in the winter, it is AC in reverse. It does not operate off gas.
If you choose emergency heat, then it bypasses the heat pump and you only use your gas furnace. With current prices, it is probably better to use the gas furnace once we get down to freezing temps. Heat pumps aren’t inefficient below -4C anyways and I’m sure someone more knowledgeable will hop in here. I have had a heat pump and gas furnace for the past 25 years so it is pretty normal.

I too am no expert and suggest to the OP to contact a reputable HVAC service company for more information. Just to clarify LANDM, there are gas fired heat pumps, although I think they are not a common item here. Interested to hear more from someone experienced in the HVAC field who can offer their input.

https://www.homeadvisor.com/r/gas-heat- ... -and-cons/

[LANDM]

Yes, but the OP's description was seeming to clearly be an electric heat pump and gas furnace. I’m not aware of dual fuel heat pumps but I certainly couldn’t say they don’t exist.

Nevertheless, Peeps comments reminded me to go and make the switchover to gas for the colder weather and current prices.

[Glacier]

Heat pumps should only be used for AC or maybe heating above 5C. This time of year until April you should only use gas. Unless you want MASSIVE electrical bills! The only time you should ever use electric heat in the winter is if you have a ground loop geothermal system.

[TylerM4]

I too am no expert and suggest to the OP to contact a reputable HVAC service company for more information. Just to clarify LANDM, there are gas fired heat pumps, although I think they are not a common item here. Interested to hear more from someone experienced in the HVAC field who can offer their input.

It's clear from the OP's post that he doesn't have a gas fired heat pump. Besides that, they're not just rare here they are rare everywhere because they fit in a very niche market and are almost never found in residential homes.

[TylerM4]

Heat pumps should only be used for AC or maybe heating above 5C. This time of year until April you should only use gas. Unless you want MASSIVE electrical bills! The only time you should ever use electric heat in the winter is if you have a ground loop geothermal system.

I don't get why people manually switch vs adjusting the automatic switch point. Easier I guess, but you only need to do it once rather than remembering to switch back and forth between seasons.

[George+]

Why would you not mine a heat pump for every degree you can get?

In cold weather heat pumps are slower to heat your home but
kicking on the electric or gas furnace right away will cost much more money.

Why not just bring up the temp a degree at a time? Do not set too low at night.

I believe some systems will use both furnace and heat pump to get temp up.

If you hear your heat pump running outside, and it says e heat or aux heat on thermo,
then you are using both.

Obviously electric heat is very clean..solar just does not work well here.
No nat. gas in my area.

[LANDM]

Why would you not mine a heat pump for every degree you can get?

In cold weather heat pumps are slower to heat your home but
kicking on the electric or gas furnace right away will cost much more money.

Why not just bring up the temp a degree at a time? Do not set too low at night.

I believe some systems will use both furnace and heat pump to get temp up.

If you hear your heat pump running outside, and it says e heat or aux heat on thermo,
then you are using both.

Obviously electric heat is very clean..solar just does not work well here.
No nat. gas in my area.

As has been noted, if you look at costs, natural gas is cheaper now vs electric so that would be the reason not to use the heat pump for as long as possible. The efficiency of extracting heat from the air as the temp gets down to -5 lowers so why use way more electricity to try to do it? If you don’t have natural gas, then none of this applies, but for the purposes of the OP, it does.

Question for those that know.....would a system use both heat pump AND natural gas furnace at the same instant? I have never seen or heard of that but my knowledge is limited.

[George+]

It was 65F when I got up and -3C outside.

About 3 hours later I am at 68 F and 0C outside.
All from the heat pump only running..no furnace.
When the furnace kicks in you can feel much stronger heat in the vents.
But right now, on the heat pump, it is moderately priced warm.

In my system the heat pump certainly does run with the furnace all Winter.

Most people put too large/quick a demand on their system instead of heating gradually.
You will not freeze to death.

[eatSleepWoof]

Thanks everyone.

Have set the thermostat to use EM/AUX heat (furnace) when outside temps drop below 3*C.

[Glacier]

It was 65F when I got up and -3C outside.

About 3 hours later I am at 68 F and 0C outside.
All from the heat pump only running..no furnace.
When the furnace kicks in you can feel much stronger heat in the vents.
But right now, on the heat pump, it is moderately priced warm.

In my system the heat pump certainly does run with the furnace all Winter.

Most people put too large/quick a demand on their system instead of heating gradually.
You will not freeze to death.

George, the fact is, all heat pumps lose efficiency as the temperature drops. At 5C you get great efficiency, like maybe 400%, but if you're running the thing at -3, you're down to maybe 150%. Maybe less, but even at 150%, you're paying way more to heat your house with electricity than you would with natural gas. Electricity is expensive relative to gas.

Currently, your gas will cost you $10.06/GJ per month. 1 GJ of electricity with BC Hydro costs you $35.75/month (2nd tier) and $43.38/month with FortisBC (also 2nd tier).

[George+]

Yes, yes but....

You are not paying for the electric furnace if it does not come on.

Most people raise the heat temp. too fast.

Currently 0C and enjoying the heat pump heat.

Fact.