"All Electric" Home with Instant Hot

[kwired]

But if you switch from gas to electric, it’s likely to cost more. My gas rates are triple what they were last year and they’re still equivalent to electricity at $0.045/KwH. That’s about 1/3 of my electric rate. Both including service, delivery charges, and taxes.

I guess if his sister switched from storage tank type gas to instant electric then yes, it possibly still cost more to heat water that way.

Instant gas water heater would been better way to go, but many only look at the initial price tag on the equipment itself and that makes electric look cheaper to them, until their electrician tells them they need to do some major upgrades after they have already installed it before it can connect to their electrical system

 

[wwhitney]

But if you switch from gas to electric, it’s likely to cost more. My gas rates are triple what they were last year and they’re still equivalent to electricity at $0.045/KwH. That’s about 1/3 of my electric rate.

If that equivalence is based on gas thermal content vs electric resistance heat, then it already shows that electric heat pumps would be about break even (COP 3). The tankless electric water heaters are rarely a good solution, but tank heat pump water heaters often are.

Cheers, Wayne

 

[kwired]

If that equivalence is based on gas thermal content vs electric resistance heat, then it already shows that electric heat pumps would be about break even (COP 3). The tankless electric water heaters are rarely a good solution, but tank heat pump water heaters often are.

Cheers, Wayne

best of both worlds, a larger storage tank heated by "waste heat" off heat pump supplying a smaller tank or instantaneous heater to assure output is at desired temperature and can give additional heat if needed in higher demand situations. Especially helpful if incoming water temp is only ~55F, at very least it kind of tempers it to around room temp during low demand periods and then it doesn't need so much temp rise before final use.

 

[mtnelect]

In California they didn't want to build anymore power plants, so Title 24 was created. HVAC is the big consideration for loads. No more "Rule of Thumb" based on square footage. You now have to do a "Herat Load" study to justify the size of the unit(s). And no more electric or gas water heaters, only Heat Pumps !

 

[wwhitney]

And no more electric or gas water heaters, only Heat Pumps !

My understanding is that's true for prescriptive compliance with the California Energy Code. Some requirements for prescriptive compliance can be waived if you do an energy analysis and show that your proposed configuration will use no more energy than the minimal prescriptive solution. I.e. you make up for the excess energy usage in one system with extra savings in another. I believe water heaters fall into that category, but I haven't checked the latest version of the CEC.

Cheers, Wayne

 

[tortuga]

And no more electric or gas water heaters, only Heat Pumps !

Are there any issues with those heat pump hater heaters? Are they loud?
I have lots of customers who can't get gas other than propane, the rummor is the heatpump water heater ends up costing less to run than propane?

 

[brantmacga]

Are there any issues with those heat pump hater heaters? Are they loud?
I have lots of customers who can't get gas other than propane, the rummor is the heatpump water heater ends up costing less to run than propane?

I watched a lot of YouTube videos on them; from what I’ve seen they are not noisy.

We replaced our electric tank heater with a tankless gas heater a little over a year ago. It would’ve been far less expensive to go with a tankless electric or heat pump, as my tank sat right next to the electrical panel. But I opted to had a gas line bored 200+ feet from the other side of the road, re-route 75’ of plumbing lines to the opposite exterior side of my house because the gas tankless is worth that trouble.

I get 3-4 calls a year from customers asking for electric tankless, and I’ve been successful at talking almost all of them out of it.

It’s worth noting I’m in the southeast, and gas right now is $0.65/therm. That’s up from $0.55/therm I’d been paying for the last 12/mo. I have a family of 4, and we use about $12/mo in gas for the water heater. My electric bill dropped about $65/mo when we disconnected the electric tank heater. My total monthly gas bill is $40; the additional $28/mo is utility fees and taxes. Even if the cost evened out or went up, it would be worth it to not have to stagger our showers, laundry, and dishwashing around the water heater. Next on the list is to switch our cooking appliances to gas.


Sent from my iPhone using Tapatalk

 

[mtnelect]

What's good about any Heat Pump is that it extracts energy needed from the air, unless it is below 50 degrees. That when it starts to struggle and needs auxiliary heat. In California it is called "Electrification" all electric for new homes. Gas appliances will be phased out (2035), because of the harmful effects on combustion.

 

[mtnelect]

Attached is what a "Heat Load Study" looks like.

 

[gadfly56]

What's good about any Heat Pump is that it extracts energy needed from the air, unless it is below 50 degrees. That when it starts to struggle and needs auxiliary heat. In California it is called "Electrification" all electric for new homes. Gas appliances will be phased out (2035), because of the harmful effects on combustion.

With any luck "the Big One" will hit soon, and the insanity leaking out of California will be curtailed as it floats off into the North Pacific.

 

[suemarkp]

What's good about any Heat Pump is that it extracts energy needed from the air, unless it is below 50 degrees. That when it starts to struggle and needs auxiliary heat. In California it is called "Electrification" all electric for new homes. Gas appliances will be phased out (2035), because of the harmful effects on combustion.

That can be good or bad. Putting a heat pump water heater in a hot California garage is a win -- cheaper hot water and a cooler garage. Putting a heat pump water heater in a utility room with no heat registers or a small one will end up being cold in that room.

There are now house heating heat pumps that still make decent warm air to well under 0F (they are called cold climate heat pumps and are typically Japanese origin). You don't need much aux heat with those. Most house heating heat pumps are rated at 47F. That is, a 4 ton heat pump makes about 48,000 BTU of heat at 47F. It will decline in output as temps decrease. I wish they would rate them at 40F and 0F. Would be a lot more useful for most of the country, and people would see how bad most of the US made heat pump are in cold temps.

 

[winnie]

I wonder about some sort of oversized heat pump, capable of heating the entire house on the coldest day with capacity to spare, also providing domestic hot water without a tank

My home has a 145k btu boiler for heat, but it runs at most 4 hours per day. My gas tankless water heater maxes at about 120k btu. I wonder if a 10 ton heat pump could do it all.

Jon

 

[wwhitney]

With any luck "the Big One" will hit soon, and the insanity leaking out of California will be curtailed as it floats off into the North Pacific.

Seriously? How would you like someone wishing 10 more Hurricane Sandys on you?

You can wrong-headedly disagree with California's energy policies, but the above is abusive.

Cheers, Wayne

 

[curt swartz]

The standard heat pump water heaters sill have 4500W resistive elements in them. All of the jobs I have worked on have had them located in the garage. Good for cooling the garage in the summer. In my opinion they are noisy.

 

[retirede]

I wonder about some sort of oversized heat pump, capable of heating the entire house on the coldest day with capacity to spare, also providing domestic hot water without a tank

My home has a 145k btu boiler for heat, but it runs at most 4 hours per day. My gas tankless water heater maxes at about 120k btu. I wonder if a 10 ton heat pump could do it all.

Jon

I would think that a tankless heat pump water heater would require such a high temperature lift that the COP would approach 1. It drops below 2 at 60C. I’ve never seen data showing a lift over 60. The alternative to high lift would be a huge (expensive) heat exchanger. It may not be practical.

 

[kwired]

What's good about any Heat Pump is that it extracts energy needed from the air, unless it is below 50 degrees. That when it starts to struggle and needs auxiliary heat. In California it is called "Electrification" all electric for new homes. Gas appliances will be phased out (2035), because of the harmful effects on combustion.

We have heat pumps set up to run down to around zero F here. Yes they are less efficient than they are at 50 F but still less cost to operate than resistance heat does. Will not get any kind of fast recovery at that kind of outdoor ambient without depending on the backup heat, but they often can maintain a temp if losses are not too significant. Also remember they draw less when not moving as much heat, but there is a "bottom" so to speak to how little they can draw.

 

[gadfly56]

We have heat pumps set up to run down to around zero F here. Yes they are less efficient than they are at 50 F but still less cost to operate than resistance heat does. Will not get any kind of fast recovery at that kind of outdoor ambient without depending on the backup heat, but they often can maintain a temp if losses are not too significant. Also remember they draw less when not moving as much heat, but there is a "bottom" so to speak to how little they can draw.

If you burn gas directly for heat, the process is typically 90-95% efficient at delivering the heat value of the fuel to the home. If you burn that gas to produce electricity, not so much. The EIA says that the US generating fleet is not quite 40% efficient turning fossil fuels into electricity. So, for 100 units of thermal energy, you get (generously) 40 units of electricity out. The distribution losses are about 9%, so now we are down to 37.4 unit of energy delivered to the heat pump. To be as efficient as direct heating, the heat pump can't operate at a COP below (90/37.4) or 2.4. And please, no nattering about how we can just increase the efficiency of the grid. We're talking about today. So, if you are in a climate zone with many more heating degree days than cooling, the barrier is a COP of 2.4.

 

[Hv&Lv]

If you burn gas directly for heat, the process is typically 90-95% efficient at delivering the heat value of the fuel to the home. If you burn that gas to produce electricity, not so much. The EIA says that the US generating fleet is not quite 40% efficient turning fossil fuels into electricity. So, for 100 units of thermal energy, you get (generously) 40 units of electricity out. The distribution losses are about 9%, so now we are down to 37.4 unit of energy delivered to the heat pump. To be as efficient as direct heating, the heat pump can't operate at a COP below (90/37.4) or 2.4. And please, no nattering about how we can just increase the efficiency of the grid. We're talking about today. So, if you are in a climate zone with many more heating degree days than cooling, the barrier is a COP of 2.4.

Not sure where that number came from…
we are about 3%, and the EIA average is 5%.
just sayin’…

 

[kwired]

If you burn gas directly for heat, the process is typically 90-95% efficient at delivering the heat value of the fuel to the home. If you burn that gas to produce electricity, not so much. The EIA says that the US generating fleet is not quite 40% efficient turning fossil fuels into electricity. So, for 100 units of thermal energy, you get (generously) 40 units of electricity out. The distribution losses are about 9%, so now we are down to 37.4 unit of energy delivered to the heat pump. To be as efficient as direct heating, the heat pump can't operate at a COP below (90/37.4) or 2.4. And please, no nattering about how we can just increase the efficiency of the grid. We're talking about today. So, if you are in a climate zone with many more heating degree days than cooling, the barrier is a COP of 2.4.

Well to most users bottom line is what is going to cost them less to operate, I get the fact that there are losses even before your meter.

A heat pump is still cost effective well below 50 degrees vs most any backup heat source that supplements it, it just that 50 degrees may very well be the point where the differences start to become less.

 

[Hv&Lv]

We have heat pumps set up to run down to around zero F here. Yes they are less efficient than they are at 50 F but still less cost to operate than resistance heat does. Will not get any kind of fast recovery at that kind of outdoor ambient without depending on the backup heat, but they often can maintain a temp if losses are not too significant. Also remember they draw less when not moving as much heat, but there is a "bottom" so to speak to how little they can draw.

I’m kind of lost here..
”set up to run down to about zero F here”..

Mine runs, period.
Now admittedly, It’s only been below 5 F 17 times here since 1940.
Our average low is lower 30s
but…

my strip heat comes on when the temp inside gets 3 degrees below the set thermostat temp.
Believe me, my wife knows that magic “3” number. She hits that spot when she wants a quick warm.