undefined | Better HN

0 pointsMarsymars5mo ago0 comments

> There’s also the argument to be made (this has manifested in other countries) that as gas usage wanes and more homes electrify, nat gas costs will increase as the infrastructure costs are spread among fewer and fewer people

This has kinda wonky incentives though - if your fixed costs for gas are high but your marginal costs remain low and for whatever logistical reasons you can't cut the gas connection entirely, then your motivations are to move as much of your heating load over to gas as possible.

0 comments

Spivak5mo ago

I'm currently facing this dilemma when it comes to my new water heater purchase. The $/kJ actually delivered into the water difference is so significant despite gas being less efficient that I'm probably going to switch to gas. Electricity has gotten so expensive that even with an efficiency advantage it still loses on the order of $500-800 per year.

MarsymarsOP5mo ago

Is gas actually less efficient? I haven't had to work out the math myself yet, but there are some very salient variables - e.g. what's the energy source of the electricity? If it's a natural gas power plant, you're looking at like 30-60% efficiency of gas->electricity in the first place. Are you looking a at a heat pump heater? If so, how much of its energy would be pulling heat from the house that needs to be replaced by the home's heating supply anyway?

This is the kind of thing where a carbon tax is great for sorting out the pricing to match the externalities.

Spivak5mo ago

You might be right, I'm just talking about "last mile" efficiency. I get electricity at $/kWh and gas at $/therm and then an electric heater is x% at converting that electricity into hotter water and a gas heater is %y. From what I can find y < x for water heaters on the market. But even despite that my $/therm is so low that it still comes out ahead.

Reason0775mo ago

> ”Are you looking a at a heat pump heater? If so, how much of its energy would be pulling heat from the house that needs to be replaced by the home's heating supply anyway?”

Heat pump water heaters pull heat from the outside. Usually with a split outdoor unit, just like normal A/C and heat pump systems.

I’ve also seen models where the entire system (integrated storage cylinder for the heated water) is installed outdoors, but those are presumably meant for more mild climates.

In any case, they certainly don’t pull heat from inside the house.

1 more reply

j / k navigate · click thread line to collapse

0 pointsMarsymars5mo ago0 comments

0 comments

Spivak5mo ago

MarsymarsOP5mo ago

This is the kind of thing where a carbon tax is great for sorting out the pricing to match the externalities.

Spivak5mo ago

Reason0775mo ago

> ”Are you looking a at a heat pump heater? If so, how much of its energy would be pulling heat from the house that needs to be replaced by the home's heating supply anyway?”

Heat pump water heaters pull heat from the outside. Usually with a split outdoor unit, just like normal A/C and heat pump systems.

I’ve also seen models where the entire system (integrated storage cylinder for the heated water) is installed outdoors, but those are presumably meant for more mild climates.

In any case, they certainly don’t pull heat from inside the house.

1 more reply

j / k navigate · click thread line to collapse