Heat pump is a no brainer for comfort heat. For domestic hot water,I'd have a 10 gallon per occupant tank heater to boost and supliment at times heat pump can't keep up with both. Stated differently. Either over-size hp or install heat pump sized to normal demand plus small tank heater for unusually cool weather and/or heavy occupancy load. Compitency of installing contractor is far more critical than choice of equipment.

My suggestion is to price out comparative usage costs before deciding to dump the gas appliances. Much of California has high electricity prices, you may not be happy with how much operating costs for heat pump appliances may run. Also, installing a ducted central heat pump is more expensive than installing a ducted gas furnace. You also may have the option of installing a new externally vented gas wall furnace.

Klem, depending upon where on the central cost this person is, heat pumps may not be the right choice. Many parts of the coastal area have no need for air conditioning and gas heating is often quite a bit less expensive.

Thanks to you both for your thoughts!

Klem, there it is again! That vague reference to a heat pump being able to do both! : ) Please bear with my under-informed self. How would that work? How would the heat pump do both? In terms of actual products, I'm only seeing water heaters or either ducted or ductless home heating systems, but nothing that would heat both my home and my water. If I want a system that does both, would I just need to find an HVAC contractor who would create such a system for me?

So far I have only looked at ductless heating, specifically a multi-zone mini-split system, because our house is not currently ducted and it's small enough that I was thinking that would be an unnecessary cost.

Elmer Fudd - I have calculated usage costs, and because of the significant increase in efficiency compared to our current 25-year-old water heater, I expect our usage costs to go down with a heat pump water heat. We will also be reducing our carbon footprint, which is equally, if not more, important to me.

There are heat pump systems which can provide domestic hot water, heating, and cooling. The most efficient type are geothermal which would require drilling on your property. However it is a large up front investment. I am not sure this type of system makes financial sense for a 1000 sq. foot home on the central coast of California.

Have you calculated your annual hot water heating cost using natural gas? What are your annual heating and cooling costs? If you provide your rates for natural gas and electricity it would be possible to do a rough calculation to estimate what it would cost to operate other types of equipment.

If your electricity is from totally renewable sources, then using heat pump technology for both your domestic hot water and your home heating is the most environmentally friendly way to go. The heat pump will probably be more expensive to install, but maybe CA has some rebates. I would like to know about the noise issue, as I'm considering replacing my electric (resistance) DHW heater with a heat pump, but it would be right under my bedroom.

"I expect our usage costs to go down with a heat pump water heat."

If your electricity is from PG+E or SoCal Edison (which is to say, electricity rates north of 20 cents per kwh), I think this is unlikely. Another cost factor to consider is that electric water heaters operate on 220-240 volts and so an electrician's work will be needed to provide a suitable circuit at the install location. The standalone units by the popular water heater brands can make a lot of noise - be careful of that too before taking the plunge.

"HVAC technology is and will be rapidly moving away from gas,"

This is patently untrue, a salesman's scare tactic. I'll guess that something more than 85% of California homes are heated with natural gas and will be for decades to come.

To suggest an air to water heat pump for a 1000 sq foot home located somewhere in coastal Cal is preposterous. If the OP wants electrical heat, a standard split heat pump would do fine but will expensive with the lack of existing ductwork, electrical wiring, and other setup costs. Split heat pumps are pretty rare in the described area, one with high electricity costs where gas heating is more economical. It's an especially odd suggestion considering it's a 1000 sq ft house previously served by one gas wall heater.

Re: Elmer J Fudd

‘HVAC technology is and will be rapidly moving away from gas,’

“This is patently untrue, a salesman's scare tactic.”

I’m not a ‘salesman’. I’m a totally disinterested party living in another country and clear across the continent as you well know, providing the OP with the specific information they asked for that no one else has thus far provided - least of all you!

If you think statements about moving away from gas are untrue then you obviously are not attending any professional conferences or seminars.

IMPO

SR

Thank you, fsq4cw. Those links were indeed exactly what I was looking for. It's much easier to research what's best for my particular situation when I know what the options are! It is definitely my hope that things in general will be "rapidly moving away from gas, oil, propane," etc.. I would like to be a part of that transition.

"I’m not a ‘salesman’."

I didn't say you were. Scare tactics are typical of fact-weak innuendo used by people in sales and others trying to advance unsupported positions. There are multiple terms to describe the obfuscation used when facts are unknown, lacking, or unconvincing. "FUD" is another term - FUD refers to injecting Fear, Uncertainty, and Doubt into a conversation when, again, facts are lacking or unconvincing.

I'm very aware of discussions and code change proposals here anyway to limit in different ways natural gas appliances in structures. Like most major changes, the consequences are not trivial and have knock-on effects. What has been discussed in the main have been proposals for rules for new construction and not for existing structures remodeling or getting new equipment.

To help you better understand and avoid scare tactics, here's a problem many haven't considered - I've seen articles that say that California (which has a larger population than your entire country) does not have sufficient electricity generating sources nor the infrastructure to support the large increase in demand that would be caused by a changeover to all-electric structures. And even though gas-fueled cars will not be allowed to be sold sometime after 2035, there is neither enough generating capacity nor power-line capacity to support this large scale demand increase either.

There was an article in a local paper a week or two ago concerning a house here in Silicon Valley that had a $40,000 rooftop solar cell system installed 6 months ago that the local electricity utility has been unable to activate. So it sits turned off and unused. Why? Because in the neighborhood where the house is located, the transformers and the power lines are not of a size that can handle the upward feed into the system on sunny days. (Most of our days are sunny days). So it remains off until the utility's hardware can be upgraded and the wait list (even at the neighborhood level) is many, many months. Multiply that problem by probably tens of thousands of locations and that's just one issue that can't be ignored. Avoiding retrofits for those of low socioeconomic means is another major problem.

Gas space and water heating will be around for a long time, decades to come.

Re: linda_reb

“Thank you, fsq4cw. Those links were indeed exactly what I was looking for. It's much easier to research what's best for my particular situation when I know what the options are! It is definitely my hope that things in general will be "rapidly moving away from gas, oil, propane," etc.. I would like to be a part of that transition.”

Here’s another link to investigate:

SpacePak Hydronic Heating And Cooling

Those that are stuck on Mini-Splits for smaller envelopes are uninformed. Some of the advantages of Mono Block Air-to-Water Heat Pumps are that just as there’s a war on fossil fuels - even natural gas, there’s a war on the use of refrigerants. Unlike mini-splits that require refrigerant lines running through the house, even if you have 1-outdoor HP unit servicing up to 4-heads, the Mono Block Air-to-Water Heat Pumps by comparison only requires a micro charge of refrigerant that is concentrated in the refrigeration circuit, all within the mono block. A much lower total refrigerant charge. The rest of the piping is virtually regular (insulated) water pipe plumbing from the HP throughout the house. It does not necessarily have to be copper piping and it’s not carrying relatively high temperate or high pressure refrigerant.

Other functions that Air-to Water Heat Pumps can perform that neither mini-splits or conventional force air cannot, are Domestic Hot Water (DHW) production, virtually instantaneous hot water production, easily zoned and even micro zones such as heated towel racks and integrated Chilled Beam cooling to name a few.

Those that think the established technologies we have today are going to be around for a long time are clearly not looking out their front windshields, they’re staring into their rearview mirrors.

Even gas utilities are now working towards transitioning off of gas where possible to what comes next.

IMPO

SR

More uninformed advice.

Air to water heat pumps are virtually unknown in California. I can't imagine but the best application would be using a hydronic air handler for forced air distribution. Why bother? Or maybe for hot water heat with radiators or radiant floors. Also quite uncommon, especially since most of the state needs AC and so would require ductwork. .

Do you think your notion is a bright idea no one has ever come up with or, more likely, might it be that your suggestion is off-base and not useful?

I still can't get over this suggestion for a 1000sq foot home previously served by one wall heater.

A simple and much less expensive solution to avoid using gas in such a small structure would be a PTAC or two or through the wall (window) heat pump (s).