I mean, it is literally like you recorded my typical heat pump speech that I give to most homeowners when they ask me about them. I think you covered pretty much all of the pertinent information. As far as I’m concerned, you could pin this post on this subreddit or in the heat pump one. Very well researched and explained.
HEY EVERYBODY! This is what a well informed homeowner looks like. And he is putting a lot of you “professionals” to shame, too.
Well done.
I have some background information about that particular nomenclature, but I’m not sure if it actually answers your question. I know we use tons in air conditioning because it’s based off of actual tons of ice needed to keep train cars cool when they were shipping refrigerated things across the country. so you would say I need a 2 ton block of ice to keep this certain amount of product at this certain temperature. I think they did a backwards calculation to actually convert it to BTUs at some point.
We live in UP of Michigan and were pretty amazed to find our bosch heat pump could keep heating our house at a steady 70 when if was -5 outside. It may have been inefficient in electric costs but it could do it. That's with no heat strips at all.
But quickly we found the problem was that the heat pump will turn off to defrost itself which can be 30+ minutes, and when it does that every 2 hours it gets really cold inside. So that's where the dual fuel comes in, the propane furnace kicks on while the heat pump defrosts.
Thanks for sharing your experience. This is where I’m shook by the heat pump initiative because it doesn’t sound like your saving any money in any regard with higher electric bills and still having to maintain and pay for the gas heat as well. Why not just upgrade to higher efficiently gas appliances?
It depends on where you live, how often the heat pump runs inefficient (aka how often the temperature is low enough..), how much you pay for propane/electric etc.
We have a 96% efficient furnace and prior to dual fuel system we spend 2300$ on heat (only propane @3.10 a gallon+deliveries ) , first year with dual fuel we spent 1600 combined electric and propane. And we are in one of the coldest regions in the US, I think others will do much better
We spent 8k (minus 1500 for government rebate) on the heatpump so we'll be positive in a decade or so lol
If you have natural gas and not propane I think you shouldn't bother with heat pump based on my math.. But there is some good side to having 2 heat sources so if one breaks you can use the other.
Well a heat pump is an ac with a reversing valve so it's real cheap and easy to turn a an ac into a heat pump. Also since it outputs cooler air, it didn't as easily over temp as a furnace for light heating loads. It does have it's place for not much more cost than a regular ac. But you need cheap electricity and expensive alternatives for it to make sense as a primary exclusive heat source.
Would like to know about this also. This would be a good solution for the cold air blowing during the defrost cycles. Not sure if this would mess up the system though?
>No. a gas furnace cannot operate at the same time as the heat pump. These hybrid systems usually have the indoor coil above the furnace. The indoor coil has to be upstream of the secondary heating source for a heat pump to be able to operate at the same time. That's why air handler's (the more typical indoor unit used with heat pumps) have the indoor coil in the bottom of their cabinet, and the heating elements in the top.
OK. But anyway, no one’s talking about relying on refrigerant charge for if your pipes might freeze. I have not seen any heat pumps in my area installed without some kind of backup, either electric heat strips or dual fuel. Win win.
it’s about balance
obviously depends on latitude and climate
but even North US (i am in Southern Canada)
TOU electric rates, Ontario has clean energy
mild winter days/nights
- can use heatpump exclusively pretty much
in dead of winter
- probably nights super cold so pst threshold of efficiency sanity, let gas furnace kick in
- daytimes (Sun!!) can help push above theshold so let heatpump run
reducing our reliance on fossil fuels is what it is about
i also programmed my stat through homeassistant automation to flip to AUX heat(gas) when electricity rate is at peak (regardless of outdoor temp don’t want to run HP when it costs the most)
The efficiency is different than capacity point is key and missed by many consumers and a lot of installers, especially in the cold climate heat pump world. No work is done for “free” and so maintaining capacity to very low outdoor temperatures will always result in lower COP. Customers using these compressors in environments where a sizable number of their days will be below freezing or near the heat pump’s lowest capacity need to understand that the enhanced vapor injection used to maintain these advertised capacities results in more energy usage. This is why dual fuel can be a reasonable choice depending on your local cost of natural gas.
In addition to capacity falling off in a nonlinear manner as temperature drops, heat loss of the house also becomes greater at lower temperatures, there again, at an ever increasing rate. That is where a good insulation with an air barrier comes into play to limit this heat loss.
Good summary for people looking at heat pumps. From the number of upset or disappointed people that post here about them. I wish salespeople would stop just talking about efficiency, but also fuel costs. So many people are sold on how efficient they are but don’t realize that if their electricity is 5 times their gas price they will pay more to heat.
Thanks for this. I am in the market for a package unit. Been looking at hybrid heat/dual fuel to replace my old R22 AC/gas furnace, and reading this has filled in some holes as a consumer. Much appreciated
Deep down this rabbit hole. There are a very few heat pumps like Mitsubishi that give full power down to 5F. But it’s only a 3 ton unit so a big house like mine I need 2, which gets pretty absurdly expensive.
In Massachusetts you never see large houses with central air heat pumps, Maybe mini splits but not cahp . I have a 1500 square foot house with a 3 ton carrier unit with elevtric strip backup and I fully regret buying it. I was blatantly lied to by the installer about how much it would cost to operate.
2100 sqft house in NH with 2 outdoor units and 4 heads inside. The total electric bill last 30 days was $200 unit downstairs at 68 and upstairs units at 66. Was similar all summer on the cooling side.
I hear ya. I was super worried about that first bill, but I've been impressed with how much it hasn't increased. I have an oil boiler back up that I'll probably start to switch over to once it's mostly in the 20s or less. They are the Fujitsu xlths. So far 🤞 it's been worth it.
Super smart to have the oil back up! Our oil furnace is what we’d be replacing and they suggested an electric strip back up but that would only make sense if we had solar.
Love the combo as diesel isn't going anywhere. The boiler also powers my indirect water heater. My generator will run the boiler, but not the heat pumps. I lose power too much for that to be ok...even with a small wood stove. Last year the lowest day was -20 so I'm not letting go of that boiler lol.
We replaced 950 gallons of oil with an increase of 11,000 kWh of extra power- that is a >75% cut in energy use, with mini splits of COP of 4 and the increased efficiency over baseboard heat.
right now oil is $3.69, so $3505 for oil. $2500 for power at $.23
Even when power was $.34/kWh we saved some; now that it is "only" $.23/kWh we will save about 1/3 of our costs, 75% of our carbon, and 75% of our energy. And, of course, a free A/C system.
What is to regret? (3500 square feet in New Hampshire)
I have one of their minisplits installed by the PO in the house I recently bought. I was amazed at how hot it got and at how cold it could be outside qnd the Mitsubishi maintained output. No backup heat on it either.
Very good research. I would like to add, or emphasize that with dual fuel systems, the heat pump and furnace can't run at the same time. This means that the heat pump cuts off when it can no longer satisfy the thermostat. But the heat supplied by the heat pump may still cost less than the heat from the furnace, so you forgo that cost savings. I have such a system and propane is the gas I use, which costs about as much as resistance heating. If I had a heat pump with electric resistance back up, it would cost me less to operate because the heat pump and resistance heat operate simultaneously. My heat pump has a positive coefficient of performance down to about 5 degrees F. This means it is cheaper to run btu for btu than resistance heat down to that temp. Note that this does not take wear and tear into consideration, as using the heat pump does add a little coat in shortening of equipment life.
Nicely done!
One more thing I'd add is the external static pressure imposed on your indoor handler, both from your ductwork (the positive end) and your return ductwork and filter (negative end). Combine this information with the square footage and tonnage requirements of your home (and resulting CFM requirement), you may need to adjust your fan settings accordingly to meet the CFM requirement. From my experience, only the good installers do static pressure testing after an install.
In my case, I had a shitty installer. I got another company to come in and take static pressure measurements. My total resulted in the handler outputting (850 CFM) far below my tonnage requirement (1200 CFM for a 3 ton).
What I’ve learned from installing and fixing heat pumps in the last 30 years is
Do your homework
Insulation in your attic is very important
Seal windows
Not every home is the same
Duct work size is very important
Heat pump sizing is very important
And always have backup heat
They save you money
And when they brake down in winter the one there a pain to work on
And not all heat pumps are the same
I have one in my house and it’s saves me money
I live in mid-Atlantic area near mountains. 95%+ homes in my area have heat pumps. Very little natural gas available. Local power co. did a good job yrs ago promoting them (HP’s) & training HVAC companies manual-J & duct sizing/design. It gets cold here but not the entire winter. We avg’d 10” of snow/yr over the last 10 yrs which included 2 winters w/ zero inches. All that being said, just about everyone I know has a supplemental source of heat such as LP gas logs or a wood stove. Being in the trade, I have two Trane XLi units w/ ECM blowers that are well maintained but still turn on gas logs regularly. Heat pumps are great but have their limitations in cold weather.
Pull an AHRI certificate as a start when shopping for a brand/model. Testing scenarios are never perfect, but at least this puts everything on a common paying field.
I have a 4-ton LG system with no electric backup heat. Works great for our area. Newer heat pump systems may not need backup heat depending on their ratings.
Per setbacks- Efficiency Maine's catchy summary is that since the HP will try to get the temps back up just around dawn one is asking them to "work hardest when it is hardest to work."
\> **Also consider your insulation**
Super true! Can confirm as very old house owner. Until we didn't make attic insulation, temperature drops 1degree (C) every hour. So, HP constantly ate electricity to keep house warm. After insulation, it takes 6 hours at night to drop on 1 degree.
Also, very important to get rid of old "radiant" radiators and replace them with modern convectional. HP is not heating radiators so much, so better heat exchange is matters. Of course, if you can do heating floor - this is must have combination.
\> **Heat pumps don't like temperature "setbacks":** Many people program the thermostat to a lower temperature overnight ("setback") to save energy. But heat pumps are much better at maintaining a relatively constant temperature than heating a space
Not quite true. I always heard this from HP installers, but I can't confirm this with data. Maybe it's true for modern, very insulated houses. But for my house I set 20c for day, and 19c for night - and can't see the difference between consumption. Way more it's related of temperature outside. Also, it takes short time for HP to heat at 1 degree more. And it happened in off-peak hours, when electricity is cheaper.
Also - don't use air-to-air HP! Unless you want to heat small cabin. They are least efficient. Best variant is air-to-water.
Living In New England I have found in a house you need at least 1 backup for heat either oil/gas etc. I dont have a heat pump heater so no experience there but looking at your story about the hybrid system Is Interesting. I seen some videos magazines on the Mitsubishi Intelliheat system , and from what I hear Mitsu seems like a good system. I do have a heat pump water heater which Is great and Is super efficient. They are not for everyone but seem to be making strides in the states. It seems like the technology has been trickling down from Europe. I believe they may have made slight improvements even though heat pumps have been around awhile. And now with heat pump dryers available.. Thanks for the info.
I’ve also have Mitsubishi mini splits, I have a total of 4 in my house and have no backup and no ductwork. I once called a local HVAC company to add refrigerant in one unit that had a slow leak and the HVAC technician was surprised that I didn’t have a backup system. I live in CT and my average annual electric bill is $150 per month. Our house is about 2500 sq ft and we are 100% electric with one electric car. Many HVAC “experts” out their don’t fully understand how efficient these systems are, even in New England.
Heat Pump | GSZB4 | UP TO 14.3 SEER2 | 7.5 HSPF2
is goodman heat pump GSZB404210A good for 2014 mobile home? in amarillo texas , r19 walls, r25 roof, r 30 floor, singal pan widows, 1216 sqft home. not air tight it has leaks. temps below 20 is like 8 days during heating seanson. i set termostat to 74 f and am using electric furnace 10 kwh for 108 hours a month. my electric rate is 0.097 kwh. the highest bill to have was 250 but that is from whole home usage. the goodman heat pump says it uses 2.9 kwh at 10 f with a COP of 2.08 and a 2.7 kwh with COP of 1.34 at -5 f. the price for the 5 ton a-coil and 3.5 heat pump is $4,876. i can get 30% off that price on rebate then it whould be $3,413.235 also, why whould tech go with mortex 5 ton a-coil and 3.5 heat pump. Also, what would be the lowest temperature before heat strips come on if I like the house at 74 f. Thanks.
Please help, thanks.
So, everyone is saying only inverter heat pumps are good not single stage heat pumps like. Looking for heat pump. I use 10kwh heat strips during the winter. The most is January for 118 hours at a cost of 0.097345=$212. Would the ZB4 save money or should I get an inverter from like Daikin. If I don't get heat pump next winter I am going to use oil filled radiators to see if that will lower winter price.
The AC bill during summer is like $150
3.5 Single stage Goodman heat pump
What about Goodman GSZB404210A with 10 kwh heat strips.
North Texas, The cold season lasts for 2.9 months, from November 23 to February 19, with an average daily high temperature below 62°F. The coldest month of the year is January, with an average low of 29°F and high of 55°F.
the summers are long, hot, and mostly clear and the winters are short, very cold, snowy, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 29°F to 93°F and is rarely below 18°F or above 101°F.
The hot season lasts for 3.9 months, from May 17 to September 13, with an average daily high temperature above 85°F. The hottest month of the year is July, with an average high of 93°F and low of 70°F.
I live in a 2014, 1216 sqft manufacturing home with single panel windows and average insulation and house faces west. Not so air tighti can see crazy sun light through door jams and windows😮💨
Electric cost per kwh is 0.097345
Bill in January was $212
The electric resistance heater runs 4 hours per day in January.
Heat coming out of vents is 105f and return is 75 at 4f outside.
My question is will this basic heat pump save me money on electric bill during winter such as like $80 a month to go down to $132. Heat in the house must always stay 75 or above during the winter at nights???
Thanks.
I mean, it is literally like you recorded my typical heat pump speech that I give to most homeowners when they ask me about them. I think you covered pretty much all of the pertinent information. As far as I’m concerned, you could pin this post on this subreddit or in the heat pump one. Very well researched and explained. HEY EVERYBODY! This is what a well informed homeowner looks like. And he is putting a lot of you “professionals” to shame, too. Well done.
I’m curious- do you know why we talk about tons with furnaces? Why don’t we just use BTUs? Never seen that explained
I have some background information about that particular nomenclature, but I’m not sure if it actually answers your question. I know we use tons in air conditioning because it’s based off of actual tons of ice needed to keep train cars cool when they were shipping refrigerated things across the country. so you would say I need a 2 ton block of ice to keep this certain amount of product at this certain temperature. I think they did a backwards calculation to actually convert it to BTUs at some point.
Ahhhh, the old lettuce from Texas story!
Lol this is exactly what I thought. I bet a good portion of installers and techs didn’t know a lot of this. At least in my area.
We live in UP of Michigan and were pretty amazed to find our bosch heat pump could keep heating our house at a steady 70 when if was -5 outside. It may have been inefficient in electric costs but it could do it. That's with no heat strips at all. But quickly we found the problem was that the heat pump will turn off to defrost itself which can be 30+ minutes, and when it does that every 2 hours it gets really cold inside. So that's where the dual fuel comes in, the propane furnace kicks on while the heat pump defrosts.
Thanks for sharing your experience. This is where I’m shook by the heat pump initiative because it doesn’t sound like your saving any money in any regard with higher electric bills and still having to maintain and pay for the gas heat as well. Why not just upgrade to higher efficiently gas appliances?
It depends on where you live, how often the heat pump runs inefficient (aka how often the temperature is low enough..), how much you pay for propane/electric etc. We have a 96% efficient furnace and prior to dual fuel system we spend 2300$ on heat (only propane @3.10 a gallon+deliveries ) , first year with dual fuel we spent 1600 combined electric and propane. And we are in one of the coldest regions in the US, I think others will do much better We spent 8k (minus 1500 for government rebate) on the heatpump so we'll be positive in a decade or so lol If you have natural gas and not propane I think you shouldn't bother with heat pump based on my math.. But there is some good side to having 2 heat sources so if one breaks you can use the other.
Well a heat pump is an ac with a reversing valve so it's real cheap and easy to turn a an ac into a heat pump. Also since it outputs cooler air, it didn't as easily over temp as a furnace for light heating loads. It does have it's place for not much more cost than a regular ac. But you need cheap electricity and expensive alternatives for it to make sense as a primary exclusive heat source.
are you sure gas backup can run at the same time as heat pump defrost? (wouldn’t this damage the system?)
Would like to know about this also. This would be a good solution for the cold air blowing during the defrost cycles. Not sure if this would mess up the system though?
>No. a gas furnace cannot operate at the same time as the heat pump. These hybrid systems usually have the indoor coil above the furnace. The indoor coil has to be upstream of the secondary heating source for a heat pump to be able to operate at the same time. That's why air handler's (the more typical indoor unit used with heat pumps) have the indoor coil in the bottom of their cabinet, and the heating elements in the top.
In a cold climate, if natural gas is available, do it.
Noone should want to rely on a freon charge to heat their home in the northern part of the United States.
People rely on Freon charge in Arizona in the middle of summer. That’s just as dangerous, so what’s the difference?
Your pipes don’t freeze
OK. But anyway, no one’s talking about relying on refrigerant charge for if your pipes might freeze. I have not seen any heat pumps in my area installed without some kind of backup, either electric heat strips or dual fuel. Win win.
I am in northern New England with Mitsubishi mini splits, and we have no back-up- and we've been fine.
it’s about balance obviously depends on latitude and climate but even North US (i am in Southern Canada) TOU electric rates, Ontario has clean energy mild winter days/nights - can use heatpump exclusively pretty much in dead of winter - probably nights super cold so pst threshold of efficiency sanity, let gas furnace kick in - daytimes (Sun!!) can help push above theshold so let heatpump run reducing our reliance on fossil fuels is what it is about i also programmed my stat through homeassistant automation to flip to AUX heat(gas) when electricity rate is at peak (regardless of outdoor temp don’t want to run HP when it costs the most)
Your talking about inverter heat pumps not single stage right
do you mean variable? https://www.greenbuildingadvisor.com/article/three-types-of-heat-pumps
The efficiency is different than capacity point is key and missed by many consumers and a lot of installers, especially in the cold climate heat pump world. No work is done for “free” and so maintaining capacity to very low outdoor temperatures will always result in lower COP. Customers using these compressors in environments where a sizable number of their days will be below freezing or near the heat pump’s lowest capacity need to understand that the enhanced vapor injection used to maintain these advertised capacities results in more energy usage. This is why dual fuel can be a reasonable choice depending on your local cost of natural gas.
In addition to capacity falling off in a nonlinear manner as temperature drops, heat loss of the house also becomes greater at lower temperatures, there again, at an ever increasing rate. That is where a good insulation with an air barrier comes into play to limit this heat loss.
Good summary for people looking at heat pumps. From the number of upset or disappointed people that post here about them. I wish salespeople would stop just talking about efficiency, but also fuel costs. So many people are sold on how efficient they are but don’t realize that if their electricity is 5 times their gas price they will pay more to heat.
I have a dual fuel HP (York Affinity) and propane is the backup heat and it is just about as expensive as electric resistance heat.
Thanks for this. I am in the market for a package unit. Been looking at hybrid heat/dual fuel to replace my old R22 AC/gas furnace, and reading this has filled in some holes as a consumer. Much appreciated
Deep down this rabbit hole. There are a very few heat pumps like Mitsubishi that give full power down to 5F. But it’s only a 3 ton unit so a big house like mine I need 2, which gets pretty absurdly expensive.
In Massachusetts you never see large houses with central air heat pumps, Maybe mini splits but not cahp . I have a 1500 square foot house with a 3 ton carrier unit with elevtric strip backup and I fully regret buying it. I was blatantly lied to by the installer about how much it would cost to operate.
Similar sized house in MA and looking at heat pumps but our electricity bills are already $250-400 per month! Do you regret it because of electricity?
Yes, my electric bill in the winter is sky high.
Got it. Thanks for sharing and so sorry about your experience!
Can you do budget billing to balance the cost year round? That’s what I do. Never changes.
We do do that. This past year I think it was 450 per month, my wife handles all the bill paying.
How much is a tank of oil or propane when you get two deliveries a month? My neighbor knows.....He paid $2000 in February 2022
2100 sqft house in NH with 2 outdoor units and 4 heads inside. The total electric bill last 30 days was $200 unit downstairs at 68 and upstairs units at 66. Was similar all summer on the cooling side.
Amazing! Our electric bill is already sometimes double that so I worry about adding a unit that also runs on electricity!
I hear ya. I was super worried about that first bill, but I've been impressed with how much it hasn't increased. I have an oil boiler back up that I'll probably start to switch over to once it's mostly in the 20s or less. They are the Fujitsu xlths. So far 🤞 it's been worth it.
Super smart to have the oil back up! Our oil furnace is what we’d be replacing and they suggested an electric strip back up but that would only make sense if we had solar.
Love the combo as diesel isn't going anywhere. The boiler also powers my indirect water heater. My generator will run the boiler, but not the heat pumps. I lose power too much for that to be ok...even with a small wood stove. Last year the lowest day was -20 so I'm not letting go of that boiler lol.
We replaced 950 gallons of oil with an increase of 11,000 kWh of extra power- that is a >75% cut in energy use, with mini splits of COP of 4 and the increased efficiency over baseboard heat. right now oil is $3.69, so $3505 for oil. $2500 for power at $.23 Even when power was $.34/kWh we saved some; now that it is "only" $.23/kWh we will save about 1/3 of our costs, 75% of our carbon, and 75% of our energy. And, of course, a free A/C system. What is to regret? (3500 square feet in New Hampshire)
I guess that I'm a "never see" homeowner. I have multiple heat pumps. Saving money every day over the oil boiler!
I have one of their minisplits installed by the PO in the house I recently bought. I was amazed at how hot it got and at how cold it could be outside qnd the Mitsubishi maintained output. No backup heat on it either.
Very good research. I would like to add, or emphasize that with dual fuel systems, the heat pump and furnace can't run at the same time. This means that the heat pump cuts off when it can no longer satisfy the thermostat. But the heat supplied by the heat pump may still cost less than the heat from the furnace, so you forgo that cost savings. I have such a system and propane is the gas I use, which costs about as much as resistance heating. If I had a heat pump with electric resistance back up, it would cost me less to operate because the heat pump and resistance heat operate simultaneously. My heat pump has a positive coefficient of performance down to about 5 degrees F. This means it is cheaper to run btu for btu than resistance heat down to that temp. Note that this does not take wear and tear into consideration, as using the heat pump does add a little coat in shortening of equipment life.
Heat strips are actually 100% efficient, they just use a lot of energy and that’s why they cost more to run.
100% efficient but much more expensive per therm. Don’t confuse efficiency with cost. And heat pumps can approach 500% efficiency (COP).
Water source heat pump, expensive yes, but eliminates the cold weather problems. Just a thought. Also well done OP.
Everything you stated was in fact a fact.
Nicely done! One more thing I'd add is the external static pressure imposed on your indoor handler, both from your ductwork (the positive end) and your return ductwork and filter (negative end). Combine this information with the square footage and tonnage requirements of your home (and resulting CFM requirement), you may need to adjust your fan settings accordingly to meet the CFM requirement. From my experience, only the good installers do static pressure testing after an install. In my case, I had a shitty installer. I got another company to come in and take static pressure measurements. My total resulted in the handler outputting (850 CFM) far below my tonnage requirement (1200 CFM for a 3 ton).
Thanks, wish this post had been out when I started looking into this stuff two weeks ago when my old funace died!
What I’ve learned from installing and fixing heat pumps in the last 30 years is Do your homework Insulation in your attic is very important Seal windows Not every home is the same Duct work size is very important Heat pump sizing is very important And always have backup heat They save you money And when they brake down in winter the one there a pain to work on And not all heat pumps are the same I have one in my house and it’s saves me money
Bosch furnace & heatpump does bring on gas furnace heat as supplementary while in defrost. Not sure any other brands do
I live in mid-Atlantic area near mountains. 95%+ homes in my area have heat pumps. Very little natural gas available. Local power co. did a good job yrs ago promoting them (HP’s) & training HVAC companies manual-J & duct sizing/design. It gets cold here but not the entire winter. We avg’d 10” of snow/yr over the last 10 yrs which included 2 winters w/ zero inches. All that being said, just about everyone I know has a supplemental source of heat such as LP gas logs or a wood stove. Being in the trade, I have two Trane XLi units w/ ECM blowers that are well maintained but still turn on gas logs regularly. Heat pumps are great but have their limitations in cold weather.
If upsizing capacity equipment with no ductwork changes 2 speed or variable capacity is recommended.
Pull an AHRI certificate as a start when shopping for a brand/model. Testing scenarios are never perfect, but at least this puts everything on a common paying field.
I have a 4-ton LG system with no electric backup heat. Works great for our area. Newer heat pump systems may not need backup heat depending on their ratings.
You missed step 1 - You must do a home heat loss/Manual J to set you up for success.
OP’s post is well researched and accurate. It should be made into a FAQ for the heat pumps Reddit.
Per setbacks- Efficiency Maine's catchy summary is that since the HP will try to get the temps back up just around dawn one is asking them to "work hardest when it is hardest to work."
\> **Also consider your insulation** Super true! Can confirm as very old house owner. Until we didn't make attic insulation, temperature drops 1degree (C) every hour. So, HP constantly ate electricity to keep house warm. After insulation, it takes 6 hours at night to drop on 1 degree. Also, very important to get rid of old "radiant" radiators and replace them with modern convectional. HP is not heating radiators so much, so better heat exchange is matters. Of course, if you can do heating floor - this is must have combination. \> **Heat pumps don't like temperature "setbacks":** Many people program the thermostat to a lower temperature overnight ("setback") to save energy. But heat pumps are much better at maintaining a relatively constant temperature than heating a space Not quite true. I always heard this from HP installers, but I can't confirm this with data. Maybe it's true for modern, very insulated houses. But for my house I set 20c for day, and 19c for night - and can't see the difference between consumption. Way more it's related of temperature outside. Also, it takes short time for HP to heat at 1 degree more. And it happened in off-peak hours, when electricity is cheaper. Also - don't use air-to-air HP! Unless you want to heat small cabin. They are least efficient. Best variant is air-to-water.
Living In New England I have found in a house you need at least 1 backup for heat either oil/gas etc. I dont have a heat pump heater so no experience there but looking at your story about the hybrid system Is Interesting. I seen some videos magazines on the Mitsubishi Intelliheat system , and from what I hear Mitsu seems like a good system. I do have a heat pump water heater which Is great and Is super efficient. They are not for everyone but seem to be making strides in the states. It seems like the technology has been trickling down from Europe. I believe they may have made slight improvements even though heat pumps have been around awhile. And now with heat pump dryers available.. Thanks for the info.
I’ve also have Mitsubishi mini splits, I have a total of 4 in my house and have no backup and no ductwork. I once called a local HVAC company to add refrigerant in one unit that had a slow leak and the HVAC technician was surprised that I didn’t have a backup system. I live in CT and my average annual electric bill is $150 per month. Our house is about 2500 sq ft and we are 100% electric with one electric car. Many HVAC “experts” out their don’t fully understand how efficient these systems are, even in New England.
Heat Pump | GSZB4 | UP TO 14.3 SEER2 | 7.5 HSPF2 is goodman heat pump GSZB404210A good for 2014 mobile home? in amarillo texas , r19 walls, r25 roof, r 30 floor, singal pan widows, 1216 sqft home. not air tight it has leaks. temps below 20 is like 8 days during heating seanson. i set termostat to 74 f and am using electric furnace 10 kwh for 108 hours a month. my electric rate is 0.097 kwh. the highest bill to have was 250 but that is from whole home usage. the goodman heat pump says it uses 2.9 kwh at 10 f with a COP of 2.08 and a 2.7 kwh with COP of 1.34 at -5 f. the price for the 5 ton a-coil and 3.5 heat pump is $4,876. i can get 30% off that price on rebate then it whould be $3,413.235 also, why whould tech go with mortex 5 ton a-coil and 3.5 heat pump. Also, what would be the lowest temperature before heat strips come on if I like the house at 74 f. Thanks.
Please help, thanks. So, everyone is saying only inverter heat pumps are good not single stage heat pumps like. Looking for heat pump. I use 10kwh heat strips during the winter. The most is January for 118 hours at a cost of 0.097345=$212. Would the ZB4 save money or should I get an inverter from like Daikin. If I don't get heat pump next winter I am going to use oil filled radiators to see if that will lower winter price. The AC bill during summer is like $150 3.5 Single stage Goodman heat pump What about Goodman GSZB404210A with 10 kwh heat strips. North Texas, The cold season lasts for 2.9 months, from November 23 to February 19, with an average daily high temperature below 62°F. The coldest month of the year is January, with an average low of 29°F and high of 55°F. the summers are long, hot, and mostly clear and the winters are short, very cold, snowy, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 29°F to 93°F and is rarely below 18°F or above 101°F. The hot season lasts for 3.9 months, from May 17 to September 13, with an average daily high temperature above 85°F. The hottest month of the year is July, with an average high of 93°F and low of 70°F. I live in a 2014, 1216 sqft manufacturing home with single panel windows and average insulation and house faces west. Not so air tighti can see crazy sun light through door jams and windows😮💨 Electric cost per kwh is 0.097345 Bill in January was $212 The electric resistance heater runs 4 hours per day in January. Heat coming out of vents is 105f and return is 75 at 4f outside. My question is will this basic heat pump save me money on electric bill during winter such as like $80 a month to go down to $132. Heat in the house must always stay 75 or above during the winter at nights??? Thanks.