8 ms·

Heat pump water heaters have efficiency of 3x+ vs .9 or so for gas or electric resistance. If you have have an electric resistance water heater get a heat pump

Heat pump water heaters have efficiency of 3x+ vs .9 or so for gas or electric resistance. If you have have an electric resistance water heater get a heat pump model. It costs more upfront but will pay for itself in not too many years, especially considering many places have incentives. In the US natural gas is so cheap the economics are not nearly as good, it takes a long time to pay back the difference but does eventually. With even a modest carbon price obviously this would be different. If you are going to replace your furnace or AC get a quote for replacing with a heat pump instead, either central or multiple mini-split heads. Heat pumps have gotten a lot better in recent years, particularly being able to work in cold weather down to 0F or below, expanding northward the places they are practical.

heatpumper 8y ago
I can tell you that my heat pump set up at my condo is absolute trash here in Northern Ohio. Running 24/7 it is unable to get my condo above 62 deg F. It blows cold-ish air under an outside temperature of 40 deg F. Windows are new, doors are weather stripped. I'm having it run it in supplemental mode just to get it above 65 deg F.
- Robotbeat 8y ago
  There are some very bad heat pumps out there. The difference in usability varies dramatically. Some heat pumps will produce heat even below 0F. Others are crappy at anything under 40F.
- mr337 8y ago
  Something must be wrong. My heatpump will run you out of the house at 40F outside. Below 20F it puts out so so heat but can maintain. Below 10F electric heat is needed from time to time to maintain. Below 0F heat pump is worthless. Edit: Wanted to add my is air heatpump, not ground source. Also reading other comments looks like heatpumps range from amazing to utter crap.
- toomuchtodo 8y ago
  1. Have an HVAC tech inspect it (~$100-150). 2. If it's not a coolant or compressor issue, you might need to replace it (either because it is undersized or end of life). Your local government or utility might have energy incentives for replacing it. There are also federal tax credit incentives [1]. [1] https://www.energystar.gov/about/federal_tax_credits/air_source_heat_pumps https://www.energystar.gov/about/federal_tax_credits/air_sou...
- czechdeveloper 8y ago
  Your heat pump just does not have sufficient capacity. It's not problem of heat pump per se.
- jandrese 8y ago
  Your heat pump is probably about 20 years old and on its last legs. Newer ones are amazing. We lopped $40 off of our electricity bill each month in the winter and $20 in the summer after we replaced ours. It pays for itself after a few years.
- dashundchen 8y ago
  From what I understand, cold weather air source heat pumps are relatively new to the market, at least in the US. Previously they were designed more for cooling loads and were essentially space heaters with an COP of 1 in cold weather. Many manufactuers seem to offer warm and cold climate models. For example, pulling a random manufactuerer, Mitsubishi brands their cold climate line "Hyper" and specs out much better efficiency down to -13F temperatures.
- ethagknight 8y ago
  My HVAC is utter crap ≠ HVACs are crap. This is a great example of a worthless anecdotal comment that distracts from the point. Give us some more detail like model number or install date? Is it a modern unit not coming close to its advertise performance? Is it appropriately sized for your condo?
- bluGill 8y ago
  A heatpump blows warm air not hot. Most people expect hot air from their vents and so are confused by not getting it. My heat pump in Iowa worked just fine to keep the house comfortable down to 14F (the system automatically switched to backup heat colder than that). Something is wrong with your system if it can't do that. I couldn't begin to guess what though.
isbjorn16 8y ago
Speaking specifically of heat pump water heaters - I will absolutely cede that they are more efficient, but holy _crap_ they take forever to recover. My previous water heater was a 70 gallon conventional electric. It didn't have quite enough hot water to get everyone through showering when we had extended family over, but it recovered reasonably quickly so that we only had ~ 30 minute gaps or so in waiting between the person who felt it get cold first and the next in line. Pretty reasonable. Ours was about 20 years old and we also wanted a bunch of other plumbing work done, so we decided we may as well bite the bullet and get a new one. We replaced ours with an 80 gallon hybrid (electric + heatpump). We figured the extra 10 gallons would probably actually completely negate the need to wait between showers for those last people, so we were super stoked. The reality is it exacerbated matters drastically. The refresh rate on our old water heater apparently was almost good enough to keep up with sustained usage between 7 people. The current one runs out of hot water out of 2 and takes well over an hour to even have enough hot water for a single next shower. I tend to take pretty long showers in the morning - like 20 minutes or so. I use a CPAP and clean my mask, I brush my teeth, I brush my invisaligns (which is why I do my teeth in the shower - it's impossible to scrub invisalign braces and not fling infinite toothpaste flotsam everywhere), and I wash myself (which honestly is the fastest part - I keep my hair next to non existent and just do a body wash from head to toe, rinse, and leave. The point is that the 20 minutes I spend in the shower, with a low flow water reducing showerhead, still means my wife gets to get a cold shower an entire hour later. However, from what I was told, there are new regulations regarding electric hot water heaters; namely, you can't get over 60 gallon tanks with a conventional hot water heater. Apparently people are getting around this by buying light industrial ones, which don't have this limitation. I wanted to try to cut down on energy usage AND I was keen on the idea of having a heat pump in my garage, transferring the heat in said garage into the water, thus leaving the garage cooler. It's like a really inefficient air conditioner for my garage, but given how hot that gets in the summer and how little I spend time in my woodworking shop, I wanted to leap at the chance to maybe make it a better environment. All of this is a long winded way of saying it may win on efficiency, and it does have a number of compelling secondary features about it, but it also still suffers from poor refractory performance. If you have one as well - do you notice issues like this? Perhaps the one I got is faulty or just ... not good.
- 8y ago
SigmundA 8y ago
Electric resistance heat is 1.0 or 100% efficient, all electricity put into the heating element is converted to heat. Not sure if your trying to include power plant conversion and transmission losses, but that gets very complicated. Gas units range in efficiency based on how much heat they recover from the exhaust, 80% is typical, 90+ for a condensing heater with two stage heat recovery. The problem with condensing is the exhaust gases fall below condensation point for the water vapor created during combustion requiring a condensate drain complicating the install location and cost significantly. Heat pumps are over unity they use some energy to move more energy from the environment into the water, they are basically solar assisted resistance heaters. The energy cost difference is not as clear when comparing a heat pump tank storage unit to a gas on demand tankless they are both typically more cost effective than tank storage electric or gas. I have a 80% efficient tankless natural gas, it is wonderful having endless hot water at all faucets concurrently with a family of 4 plus occasional guests. I wanted to go condensing 90+ efficient but it was to complex based on its install location.
- fulafel 8y ago
  In typical mounting of electric radiator elements, some of the heat might be absorbed in the walls and windows that are facing outdoors. Then the temperature gardient in the wall/window insulation is steeper, leaking more heat outside. So yes, all the energy is converted into heat, but some of it may be heating the outdoors.
  - SigmundA 8y ago
    This has nothing to do with the type of heater but rather the placement. When talking about relative efficiency you look at the heater itself and not common factors as they can be eliminated from the equation.

heatpumper 8y ago

I can tell you that my heat pump set up at my condo is absolute trash here in Northern Ohio. Running 24/7 it is unable to get my condo above 62 deg F. It blows cold-ish air under an outside temperature of 40 deg F. Windows are new, doors are weather stripped. I'm having it run it in supplemental mode just to get it above 65 deg F.

Robotbeat 8y ago
There are some very bad heat pumps out there. The difference in usability varies dramatically. Some heat pumps will produce heat even below 0F. Others are crappy at anything under 40F.
mr337 8y ago
Something must be wrong. My heatpump will run you out of the house at 40F outside. Below 20F it puts out so so heat but can maintain. Below 10F electric heat is needed from time to time to maintain. Below 0F heat pump is worthless. Edit: Wanted to add my is air heatpump, not ground source. Also reading other comments looks like heatpumps range from amazing to utter crap.
toomuchtodo 8y ago
1. Have an HVAC tech inspect it (~$100-150). 2. If it's not a coolant or compressor issue, you might need to replace it (either because it is undersized or end of life). Your local government or utility might have energy incentives for replacing it. There are also federal tax credit incentives [1]. [1] https://www.energystar.gov/about/federal_tax_credits/air_source_heat_pumps https://www.energystar.gov/about/federal_tax_credits/air_sou...
czechdeveloper 8y ago
Your heat pump just does not have sufficient capacity. It's not problem of heat pump per se.
jandrese 8y ago
Your heat pump is probably about 20 years old and on its last legs. Newer ones are amazing. We lopped $40 off of our electricity bill each month in the winter and $20 in the summer after we replaced ours. It pays for itself after a few years.
dashundchen 8y ago
From what I understand, cold weather air source heat pumps are relatively new to the market, at least in the US. Previously they were designed more for cooling loads and were essentially space heaters with an COP of 1 in cold weather. Many manufactuers seem to offer warm and cold climate models. For example, pulling a random manufactuerer, Mitsubishi brands their cold climate line "Hyper" and specs out much better efficiency down to -13F temperatures.
ethagknight 8y ago
My HVAC is utter crap ≠ HVACs are crap. This is a great example of a worthless anecdotal comment that distracts from the point. Give us some more detail like model number or install date? Is it a modern unit not coming close to its advertise performance? Is it appropriately sized for your condo?
bluGill 8y ago
A heatpump blows warm air not hot. Most people expect hot air from their vents and so are confused by not getting it. My heat pump in Iowa worked just fine to keep the house comfortable down to 14F (the system automatically switched to backup heat colder than that). Something is wrong with your system if it can't do that. I couldn't begin to guess what though.

isbjorn16 8y ago

Speaking specifically of heat pump water heaters - I will absolutely cede that they are more efficient, but holy _crap_ they take forever to recover. My previous water heater was a 70 gallon conventional electric. It didn't have quite enough hot water to get everyone through showering when we had extended family over, but it recovered reasonably quickly so that we only had ~ 30 minute gaps or so in waiting between the person who felt it get cold first and the next in line. Pretty reasonable. Ours was about 20 years old and we also wanted a bunch of other plumbing work done, so we decided we may as well bite the bullet and get a new one. We replaced ours with an 80 gallon hybrid (electric + heatpump). We figured the extra 10 gallons would probably actually completely negate the need to wait between showers for those last people, so we were super stoked. The reality is it exacerbated matters drastically. The refresh rate on our old water heater apparently was almost good enough to keep up with sustained usage between 7 people. The current one runs out of hot water out of 2 and takes well over an hour to even have enough hot water for a single next shower. I tend to take pretty long showers in the morning - like 20 minutes or so. I use a CPAP and clean my mask, I brush my teeth, I brush my invisaligns (which is why I do my teeth in the shower - it's impossible to scrub invisalign braces and not fling infinite toothpaste flotsam everywhere), and I wash myself (which honestly is the fastest part - I keep my hair next to non existent and just do a body wash from head to toe, rinse, and leave. The point is that the 20 minutes I spend in the shower, with a low flow water reducing showerhead, still means my wife gets to get a cold shower an entire hour later. However, from what I was told, there are new regulations regarding electric hot water heaters; namely, you can't get over 60 gallon tanks with a conventional hot water heater. Apparently people are getting around this by buying light industrial ones, which don't have this limitation. I wanted to try to cut down on energy usage AND I was keen on the idea of having a heat pump in my garage, transferring the heat in said garage into the water, thus leaving the garage cooler. It's like a really inefficient air conditioner for my garage, but given how hot that gets in the summer and how little I spend time in my woodworking shop, I wanted to leap at the chance to maybe make it a better environment. All of this is a long winded way of saying it may win on efficiency, and it does have a number of compelling secondary features about it, but it also still suffers from poor refractory performance. If you have one as well - do you notice issues like this? Perhaps the one I got is faulty or just ... not good.

8y ago

SigmundA 8y ago

Electric resistance heat is 1.0 or 100% efficient, all electricity put into the heating element is converted to heat. Not sure if your trying to include power plant conversion and transmission losses, but that gets very complicated. Gas units range in efficiency based on how much heat they recover from the exhaust, 80% is typical, 90+ for a condensing heater with two stage heat recovery. The problem with condensing is the exhaust gases fall below condensation point for the water vapor created during combustion requiring a condensate drain complicating the install location and cost significantly. Heat pumps are over unity they use some energy to move more energy from the environment into the water, they are basically solar assisted resistance heaters. The energy cost difference is not as clear when comparing a heat pump tank storage unit to a gas on demand tankless they are both typically more cost effective than tank storage electric or gas. I have a 80% efficient tankless natural gas, it is wonderful having endless hot water at all faucets concurrently with a family of 4 plus occasional guests. I wanted to go condensing 90+ efficient but it was to complex based on its install location.

fulafel 8y ago
In typical mounting of electric radiator elements, some of the heat might be absorbed in the walls and windows that are facing outdoors. Then the temperature gardient in the wall/window insulation is steeper, leaking more heat outside. So yes, all the energy is converted into heat, but some of it may be heating the outdoors.
- SigmundA 8y ago
  This has nothing to do with the type of heater but rather the placement. When talking about relative efficiency you look at the heater itself and not common factors as they can be eliminated from the equation.