Heat pump water heaters

[Anonymous]

Just read about these

https://www.npr.org/2023/10/03/1196977935/save-money-energy-tips

Does anybody in the dmv have one?

[Anonymous]

My answer to all the options in the article is "no".

For example, heat pumps blow air around they sure do and do not warm effectively in the coldest of weather. Ever have to use the auxillary heat function in super cold weather? $$$$ on electric bill.

[Anonymous]

Oh and this is PP, these newfangled heat pump water heaters move heat from room into the water. We just are then not going to have very hot water.

So in concusion, all these changes will cost up more $$$, they will not work as well as that things we are used to, but we should not care because of the "environment".

[Anonymous]

In the summer, it does make some sense. You are going to have excess heat in your home. In the winter, you are just creating additional load on what is likely a heat pump heating your home.

Heat pumps are more efficient in general because they are just moving heat around instead of converting electricity into heat. They are objectively better for the environment.

[Anonymous]

Heat pumps start to suck at places just slightly colder than DC. We’re on the margin of suitable winter climate for heat pumps. They work much better in places like the Carolinas and are outstanding in GA and FL.

If you have a ground loop or geothermal well for the heat pump, where the evaporator coil is guaranteed never to get below 50-55 degrees, heat pumps can work great in even cold climates (we’re not “cold” here in DC) But the typical DC area heat pump set up with an outdoor unit with an atmospheric coil is right on the edge of not working here.

[Anonymous]

Anonymous wrote:In the summer, it does make some sense. You are going to have excess heat in your home. In the winter, you are just creating additional load on what is likely a heat pump heating your home.

Heat pumps are more efficient in general because they are just moving heat around instead of converting electricity into heat. They are objectively better for the environment.

They’re not moving sufficient heat around when the evap coil is surrounded by ~20F ambient air. Hence resistance heating coils to supplement it. Heat pumps suck at this latitude and climate.

[Anonymous]

Anonymous wrote:In the summer, it does make some sense. You are going to have excess heat in your home. In the winter, you are just creating additional load on what is likely a heat pump heating your home.

Heat pumps are more efficient in general because they are just moving heat around instead of converting electricity into heat. They are objectively better for the environment.

They’re not objectively better for sh*t if they’re relying on grossly inefficient heating elements to make heat because it’s too cold for them to function thermodynamically.

For thermal efficiency sake you’d be much better off burning natural gas and heating the air directly than burning natural gas at some power plant, generating power, transmitting it (and losing some along the way) and THEN trying to turn it BACK into hot air again through electrical resistance. Each step along the way knocks off another 20+ % efficiency.

[Anonymous]

Anonymous wrote:

Anonymous wrote:In the summer, it does make some sense. You are going to have excess heat in your home. In the winter, you are just creating additional load on what is likely a heat pump heating your home.

Heat pumps are more efficient in general because they are just moving heat around instead of converting electricity into heat. They are objectively better for the environment.

They’re not objectively better for sh*t if they’re relying on grossly inefficient heating elements to make heat because it’s too cold for them to function thermodynamically.

For thermal efficiency sake you’d be much better off burning natural gas and heating the air directly than burning natural gas at some power plant, generating power, transmitting it (and losing some along the way) and THEN trying to turn it BACK into hot air again through electrical resistance. Each step along the way knocks off another 20+ % efficiency.

Can't let facts get in the way of "but the environment!"

[Anonymous]

Anonymous wrote:

Anonymous wrote:In the summer, it does make some sense. You are going to have excess heat in your home. In the winter, you are just creating additional load on what is likely a heat pump heating your home.

Heat pumps are more efficient in general because they are just moving heat around instead of converting electricity into heat. They are objectively better for the environment.

They’re not objectively better for sh*t if they’re relying on grossly inefficient heating elements to make heat because it’s too cold for them to function thermodynamically.

For thermal efficiency sake you’d be much better off burning natural gas and heating the air directly than burning natural gas at some power plant, generating power, transmitting it (and losing some along the way) and THEN trying to turn it BACK into hot air again through electrical resistance. Each step along the way knocks off another 20+ % efficiency.

Racist.

[Anonymous]

Anonymous wrote:Heat pumps start to suck at places just slightly colder than DC. We’re on the margin of suitable winter climate for heat pumps. They work much better in places like the Carolinas and are outstanding in GA and FL.

If you have a ground loop or geothermal well for the heat pump, where the evaporator coil is guaranteed never to get below 50-55 degrees, heat pumps can work great in even cold climates (we’re not “cold” here in DC) But the typical DC area heat pump set up with an outdoor unit with an atmospheric coil is right on the edge of not working here.

Heat pumps have improved over recent years. There are "cold-climate heat pumps" that can operate efficiently well below at extreme low temperatures:

https://www.reddit.com/r/heatpumps/comments/146jg7k/cold_climate_heat_pump_owners_what_model_did_you/

Some people argue that heat pumps can't help with CO2 reduction because they are typically powered by an electrical grid that runs on fossil fuels. And they point out that a lot of the energy and heat goes up the smokestack of the power plant, which is wasteful. It is true that energy is lost at the site of power generation, but, even so, heat pumps can reduce CO2 emissions (relative to gas furnace heating) due to their high efficiency. Suppose that 30% of energy is wasted at the site of power generation. So only 70% of the original energy reaches the customers. But if customers are running heat pumps that are 200% efficient, the waste at the central power plant is more than offset by the efficiency of the heat pump. The result is that heat pumps can lead to significant emissions reductions relative to gas furnaces. And yes, good heat pumps can keep your house warm even in frigid weather.

[Anonymous]

Anonymous wrote:

Anonymous wrote:Heat pumps start to suck at places just slightly colder than DC. We’re on the margin of suitable winter climate for heat pumps. They work much better in places like the Carolinas and are outstanding in GA and FL.

If you have a ground loop or geothermal well for the heat pump, where the evaporator coil is guaranteed never to get below 50-55 degrees, heat pumps can work great in even cold climates (we’re not “cold” here in DC) But the typical DC area heat pump set up with an outdoor unit with an atmospheric coil is right on the edge of not working here.

Heat pumps have improved over recent years. There are "cold-climate heat pumps" that can operate efficiently well below at extreme low temperatures:

https://www.reddit.com/r/heatpumps/comments/146jg7k/cold_climate_heat_pump_owners_what_model_did_you/

Some people argue that heat pumps can't help with CO2 reduction because they are typically powered by an electrical grid that runs on fossil fuels. And they point out that a lot of the energy and heat goes up the smokestack of the power plant, which is wasteful. It is true that energy is lost at the site of power generation, but, even so, heat pumps can reduce CO2 emissions (relative to gas furnace heating) due to their high efficiency. Suppose that 30% of energy is wasted at the site of power generation. So only 70% of the original energy reaches the customers. But if customers are running heat pumps that are 200% efficient, the waste at the central power plant is more than offset by the efficiency of the heat pump. The result is that heat pumps can lead to significant emissions reductions relative to gas furnaces. And yes, good heat pumps can keep your house warm even in frigid weather.

They are "efficient" because they are not providing as much warmth, so that is not efficient because they are not providing the same warmth using less energy. That is like calling HE washer efficient because they use less water. Not they would actually be efficient if they worked the exact same way as the old machines by using less water but they don't. Taking away or providing inferior features to appliances just to create an appliance that uses less energy is not efficient. We are just getting a different kind of appliance.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Heat pumps start to suck at places just slightly colder than DC. We’re on the margin of suitable winter climate for heat pumps. They work much better in places like the Carolinas and are outstanding in GA and FL.

If you have a ground loop or geothermal well for the heat pump, where the evaporator coil is guaranteed never to get below 50-55 degrees, heat pumps can work great in even cold climates (we’re not “cold” here in DC) But the typical DC area heat pump set up with an outdoor unit with an atmospheric coil is right on the edge of not working here.

Heat pumps have improved over recent years. There are "cold-climate heat pumps" that can operate efficiently well below at extreme low temperatures:

https://www.reddit.com/r/heatpumps/comments/146jg7k/cold_climate_heat_pump_owners_what_model_did_you/

Some people argue that heat pumps can't help with CO2 reduction because they are typically powered by an electrical grid that runs on fossil fuels. And they point out that a lot of the energy and heat goes up the smokestack of the power plant, which is wasteful. It is true that energy is lost at the site of power generation, but, even so, heat pumps can reduce CO2 emissions (relative to gas furnace heating) due to their high efficiency. Suppose that 30% of energy is wasted at the site of power generation. So only 70% of the original energy reaches the customers. But if customers are running heat pumps that are 200% efficient, the waste at the central power plant is more than offset by the efficiency of the heat pump. The result is that heat pumps can lead to significant emissions reductions relative to gas furnaces. And yes, good heat pumps can keep your house warm even in frigid weather.

They are "efficient" because they are not providing as much warmth, so that is not efficient because they are not providing the same warmth using less energy. That is like calling HE washer efficient because they use less water. Not they would actually be efficient if they worked the exact same way as the old machines by using less water but they don't. Taking away or providing inferior features to appliances just to create an appliance that uses less energy is not efficient. We are just getting a different kind of appliance.

We live in Northern VA and have a heat pump. We are satisfied. At least based on our personal experience, the heat pump is quite effective at warming our home.

[Anonymous]

Anonymous wrote:

Anonymous wrote:Heat pumps start to suck at places just slightly colder than DC. We’re on the margin of suitable winter climate for heat pumps. They work much better in places like the Carolinas and are outstanding in GA and FL.

If you have a ground loop or geothermal well for the heat pump, where the evaporator coil is guaranteed never to get below 50-55 degrees, heat pumps can work great in even cold climates (we’re not “cold” here in DC) But the typical DC area heat pump set up with an outdoor unit with an atmospheric coil is right on the edge of not working here.

Heat pumps have improved over recent years. There are "cold-climate heat pumps" that can operate efficiently well below at extreme low temperatures:

https://www.reddit.com/r/heatpumps/comments/146jg7k/cold_climate_heat_pump_owners_what_model_did_you/

Some people argue that heat pumps can't help with CO2 reduction because they are typically powered by an electrical grid that runs on fossil fuels. And they point out that a lot of the energy and heat goes up the smokestack of the power plant, which is wasteful. It is true that energy is lost at the site of power generation, but, even so, heat pumps can reduce CO2 emissions (relative to gas furnace heating) due to their high efficiency. Suppose that 30% of energy is wasted at the site of power generation. So only 70% of the original energy reaches the customers. But if customers are running heat pumps that are 200% efficient, the waste at the central power plant is more than offset by the efficiency of the heat pump. The result is that heat pumps can lead to significant emissions reductions relative to gas furnaces. And yes, good heat pumps can keep your house warm even in frigid weather.

I realize I’m only a stupid mechanical and electrical engineer who didn’t get a liberal arts degree from an Ivy, but perhaps one of you smart MBA’s or PhD’s can explain the whole “200% efficiency” thing to me?

Because I’m absolutely dying to hear this one….

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:In the summer, it does make some sense. You are going to have excess heat in your home. In the winter, you are just creating additional load on what is likely a heat pump heating your home.

Heat pumps are more efficient in general because they are just moving heat around instead of converting electricity into heat. They are objectively better for the environment.

They’re not objectively better for sh*t if they’re relying on grossly inefficient heating elements to make heat because it’s too cold for them to function thermodynamically.

For thermal efficiency sake you’d be much better off burning natural gas and heating the air directly than burning natural gas at some power plant, generating power, transmitting it (and losing some along the way) and THEN trying to turn it BACK into hot air again through electrical resistance. Each step along the way knocks off another 20+ % efficiency.

Racist.

Understanding thermodynamics makes me a racist.

Got it.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Heat pumps start to suck at places just slightly colder than DC. We’re on the margin of suitable winter climate for heat pumps. They work much better in places like the Carolinas and are outstanding in GA and FL.

If you have a ground loop or geothermal well for the heat pump, where the evaporator coil is guaranteed never to get below 50-55 degrees, heat pumps can work great in even cold climates (we’re not “cold” here in DC) But the typical DC area heat pump set up with an outdoor unit with an atmospheric coil is right on the edge of not working here.

Heat pumps have improved over recent years. There are "cold-climate heat pumps" that can operate efficiently well below at extreme low temperatures:

https://www.reddit.com/r/heatpumps/comments/146jg7k/cold_climate_heat_pump_owners_what_model_did_you/

Some people argue that heat pumps can't help with CO2 reduction because they are typically powered by an electrical grid that runs on fossil fuels. And they point out that a lot of the energy and heat goes up the smokestack of the power plant, which is wasteful. It is true that energy is lost at the site of power generation, but, even so, heat pumps can reduce CO2 emissions (relative to gas furnace heating) due to their high efficiency. Suppose that 30% of energy is wasted at the site of power generation. So only 70% of the original energy reaches the customers. But if customers are running heat pumps that are 200% efficient, the waste at the central power plant is more than offset by the efficiency of the heat pump. The result is that heat pumps can lead to significant emissions reductions relative to gas furnaces. And yes, good heat pumps can keep your house warm even in frigid weather.

I realize I’m only a stupid mechanical and electrical engineer who didn’t get a liberal arts degree from an Ivy, but perhaps one of you smart MBA’s or PhD’s can explain the whole “200% efficiency” thing to me?

Because I’m absolutely dying to hear this one….

Jesus Christ you are stupid. The efficiency comes as a result of transferring heat rather than creating heat. It is much more efficient.

Anyway, to op’s point, we have one. Over time it has worked out somewhat cheaper than gas.