Heat Pump Recommendations

[u3b3rg33k]

Not a bad idea, I could do it with a smart switch/zwave to only do it under certain conditions. I do wonder if the Econet will throw an error when it doesn't see the heat rise it wants though.

does your econet have a DATS? or just room temp?

No, backup heat is so you do not have to rely on a HP when the weather gets too cold. For example, my HP provided heat at -18c but it took an hour to go from 16c to 20c. At -5c that 16c to 20c can happen in 5 minutes. When power is out that means my furnace doesn't work but my gas stove still does work.

HP's work efficiently and mostly constantly. They are most efficient at light loads. They are not like a gas furnace that blasts heat and then shuts off.

depends on a lot of things. most are controlled that way (on/off, if you're lucky 2 stage).
an hour for 8F gain seems good to me, especially if it's not using strips to augment.

sometimes power grid going down can take out NG pumping stations, and then whoops!

or the NG pipeline supply has a problem and they ask the whole region to turn the thermostats down! guess you need a wood stove.

Of course and your HP won't work at -45c = -49F which Alberta saw 2 weeks of in January. That is why you need a backup source of heat.

if everyone is cooking strips in Alberta when it's -50F out, the grid is going down, lol.
texas made the same mistake.

"just install electric furnaces, you'll never need it!"

Oops! can't heat texas with hairdryers (but you could with heatpumps since the grid is built for 24/7 AC)! guess it's blackout time!

 

[pcmeiners]

You need it but 99.8% of the Americas do not get anywhere near -49 ° . but power outages are becoming more common. I like cold weather but have to admit -49° F is more than I or my engine block ever wants. I checked out some of the temperatures up there, some colder than -45 °C, I guess hibernation is the way to go.

 

[P0234]

does your econet have a DATS? or just room temp?

Not sure what DATS is, but it knows the temperature of the interior coil (as well as exterior temp, ext coil, pressures on, superheat, etc, tons of data available at the thermostat). One of the projects I want to get to soon:

GitHub - esphome-econet/esphome-econet: esphome-econet is a package for controlling a Rheem water heater or HVAC system with an esp32 or esp8266 micro-computer.

esphome-econet is a package for controlling a Rheem water heater or HVAC system with an esp32 or esp8266 micro-computer. - esphome-econet/esphome-econet

github.com

 

[u3b3rg33k]

Not sure what DATS is, but it knows the temperature of the interior coil (as well as exterior temp, ext coil, pressures on, superheat, etc, tons of data available at the thermostat). One of the projects I want to get to soon:

GitHub - esphome-econet/esphome-econet: esphome-econet is a package for controlling a Rheem water heater or HVAC system with an esp32 or esp8266 micro-computer.

esphome-econet is a package for controlling a Rheem water heater or HVAC system with an esp32 or esp8266 micro-computer. - esphome-econet/esphome-econet

github.com

discharge air temp sensor.

sounds like you've got a communicating stat.

 

[P0234]

discharge air temp sensor.

sounds like you've got a communicating stat.

Got it, will have to look. To your point unless I have a DAT, it wouldn't know but if the thermostat senses a drop in temp, its not shy to call Mr. Coil for help.

 

[u3b3rg33k]

Got it, will have to look. To your point unless I have a DAT, it wouldn't know but if the thermostat senses a drop in temp, its not shy to call Mr. Coil for help.

that behavior should be programmable/adjustable. my personal fav, the honeywell redlink IAQ, allows stage 3/aux heat lockout above a user setpoint (outdoor air temp). that feature alone can pay for the thermostat upgrade over a dumb stat in under a month.

 

[theoldwizard1]

No, backup heat is so you do not have to rely on a HP when the weather gets too cold. For example, my HP provided heat at -18c but it took an hour to go from 16c to 20c. At -5c that 16c to 20c can happen in 5 minutes.

You are confusing "backup heat source" with "auxillary heat source".

Backup is what you use when there is no power. We live in the middle of sububia. My daughter was without power for 3 days last fall. I wired a portable generator to the furnace to keep the house above 60F

 

[pcmeiners]

"
Is it one of the latest inverter compressors? I hear those are insanely efficient for their size.

they are when they're not using the full capacity of the system."

They are insanely efficient on average, what more can you ask for? A perfect heat and cooling curve you ain't go to get, settle for an average 400% efficiency, COP=4 (top models). I expect to heat an cool my home *1280sqft, and garage 1080 sqft for $ 1200-1300 for the year, only geo or added solar will do better, excluding hot water heating, at most $200.

 

[bonneyman]

they are when they're not using the full capacity of the system."

They are insanely efficient on average, what more can you ask for? A perfect heat and cooling curve you ain't go to get, settle for an average 400% efficiency, COP=4 (top models). I expect to heat an cool my home *1280sqft, and garage 1080 sqft for $ 1200-1300 for the year, only geo or added solar will do better.

The perfect heating and cooling system is the one I don't have to pay for!

 

[pcmeiners]

"The perfect heating and cooling system is the one I don't have to pay for!"

Collect Medicaid and you won't have to pay a dime.

 

[Steve_P]

"The perfect heating and cooling system is the one I don't have to pay for!"

Collect Medicaid and you won't have to pay a dime.

Brilliant! So, all we need to do is earn poverty wages- therefore live in poverty, apply for heating aid, hope you get it, hope there is enough $ available, take what you might get- and then hope that what you might get pays the bills...... That REALLY sounds like a great plan- I'm sure we'll all quit our jobs and rush out to work at Wal Mart part time and live in poverty for a chance to get partially subsidized heat in the winter

 

[pcmeiners]

Sarcasm

 

[theoldwizard1]

The perfect heating and cooling system is the one I don't have to pay for!

Large solar array, large battery bank, large inverters, several mini-split heat pumps.

 

[nbpt100]

Large solar array, large battery bank, large inverters, several mini-split heat pumps.

That is as close as you will get to having a tiny monthly electric bill. AS someone much smarter than I once said, " There is no such thing as a free lunch". You pay a lot up front or as you go. But you are still paying a lot. Calculating a payback time is the way to best understand the cost benefits.

 

[theoldwizard1]

You pay a lot up front or as you go. But you are still paying a lot. Calculating a payback time is the way to best understand the cost benefits.

I agree !

Calculating payback time is very difficult. Most people who did more than a "back of the envelope" calculation, beat their estimates.

 

[Lassen Forge]

You nees to have a 2nd (maybe a 3rd) source of heat.... our system (which I love) will actually push air out at 32C (89.?? F) consistantly. Our compressor/fan "box" can be run with 3 splits, tho we only have 2 in use so far. We also have an alternate heat source to break the chill in winter (a traditional caldaia/radiator thing common here in Italy) as our buildings are generally stone or brick (or both) and the cold soak *****. The radiators break the chill and the heat pump maintains (and raises) the temperature quite nicely.

Thing is, you DO get what you pay for. The 2 biggies here are Daikin and Mitsubishi (both old school Japanese brands) and they're middle-high price... BUT... I know people that went with Chinese units (LG, Candy, Haier, etc.) and they tend to be not as efficient, and a few have given friends trouble almost from the start... Ours is a Mitsubishi inverter unit (little better for heat), and I have NEVER regretted it for a second.

.

 

[nbpt100]

I agree !

Calculating payback time is very difficult. Most people who did more than a "back of the envelope" calculation, best their estimates.

Yes it is. Gas is priced in therms and Electricity is priced in KWatt-Hours. You need to understand you have to maintain a second heat source. Weather it is gas, oil, electric base board. Gas or oil burners need maintenance and need to be replaced every 20 to 30 years. The heat pump is only good for 15 years. Not easy to predict future replacement price. I have been quoted the annual maintenance on a minisplit type of heat pump to be $250 per year per unit. I am not considering this but I know a few who had them installed and were shocked by the annual maintenance cost. There were wooed in by being Cheaper than a full central air install, and not having to deal with window AC units any longer.

 

[theoldwizard1]

You need to understand you have to maintain a second heat source.

You need a backup heat source only if you have anything that will be damaged from freezing during an extended power outage.

OP is in NC. Might not need it.

 

[P0234]

Yes it is. Gas is priced in therms and Electricity is priced in KWatt-Hours. You need to understand you have to maintain a second heat source. Weather it is gas, oil, electric base board. Gas or oil burners need maintenance and need to be replaced every 20 to 30 years. The heat pump is only good for 15 years. Not easy to predict future replacement price. I have been quoted the annual maintenance on a minisplit type of heat pump to be $250 per year per unit. I am not considering this but I know a few who had them installed and were shocked by the annual maintenance cost. There were wooed in by being Cheaper than a full central air install, and not having to deal with window AC units any longer.

You know it's amazing fridges can go 20+ years and not need a thing, not even a coil vacuuming. Yet some HVAC companies seem the think certain systems need "service" 2x a year.

 

[toyotadriver]

You know it's amazing fridges can go 20+ years and not need a thing, not even a coil vacuuming. Yet some HVAC companies seem the think certain systems need "service" 2x a year.

I had a refrigerator die an early death a few years ago. Bought a new refrigerator to replace it and when I moved out the dead one, I noticed the coils, which were on the bottom, were completely clogged with dust. Since then, I clean the coils 2 times per year. Vacuum and compressed air makes it a quick job.



Nothing in this post should be misunderstood, interpreted, misinterpreted, or construed to be of a political nature.

 

[danski0224]

You know it's amazing fridges can go 20+ years and not need a thing, not even a coil vacuuming. Yet some HVAC companies seem the think certain systems need "service" 2x a year.

A refrigerator is typically a sealed system built in a factory.

A residential HVAC system is assembled in the field.

Having it checked can catch things like refrigerant loss, which may lead to a leaking evaporator coil, which may be covered under a parts warranty.

But, you go ahead and you do you.

 

[P0234]

A refrigerator is typically a sealed system built in a factory.

A residential HVAC system is assembled in the field.

Having it checked can catch things like refrigerant loss, which may lead to a leaking evaporator coil, which may be covered under a parts warranty.

But, you go ahead and you do you.

That's something that could be accomplished with a couple of pressure sensors that would add less to the cost of a unit than one service call.

Look, I'm not saying service calls aren't needed, but twice a year is excessive.

My last house never called once, went almost ten years. Just washed the coils here and there and kept track of my temp differential. What would ten years of service calls 2x a year cost on two units?

 

[nbpt100]

You need a backup heat source only if you have anything that will be damaged from freezing during an extended power outage.

OP is in NC. Might not need it.

OK maybe.

Just so people reading this are not confused. Modern heat pumps are good alone down to about 28F. This is what my HVAC guy has told me. At About that temperature the supplemental heat kicks in. So in a location where it never gets that cold, you can get away with no supplemental heat source. Back up heat is something else. It is when your unit dies or the electricity goes out (no generator or batteries) and you need to look elsewhere for heat.

You know it's amazing fridges can go 20+ years and not need a thing, not even a coil vacuuming. Yet some HVAC companies seem the think certain systems need "service" 2x a year.

I was told the annual mini split service is important to clean it of any mold. Apparently they collect mold more so that other type of AC or heating units. IDK, just what I have been told. I have noticed the larger HVAC and Plumbing companies in this area are pushing service contracts. If you are not under contract with them they will not put you on priority if you have an emergency with the heat cutting out in the middle of winter. In other words they will take their sweet time to show up if you do not pay them the contract fee every year. Some call this extortion while others call it smart business.

Old Fridges seem to last for almost ever. I have a 40 yr old Admiral that is still working. Some of the plastic parts are cracking but it still keeps everything cold. It uses R12.
Fridges bought in the past 5 years have had a lot of quality issues and defects in manufacturing. This is anecdotal from my conversations with a lot of people who have purchased Fridges in this time frame. Lots of warranty calls and things like door handles breaking. My Real Estate agent has confirmed this with me and has said to stay away from certain brands that use to be thought of as quality.

 

[danski0224]

twice a year

One heat, one cooling (furnace + AC).

Heat pump, check in cooling.

 

[P0234]

OK maybe.

Just so people reading this are not confused. Modern heat pumps are good alone down to about 28F. This is what my HVAC guy has told me. At About that temperature the supplemental heat kicks in. So in a location where it never gets that cold, you can get away with no supplemental heat source. Back up heat is something else. It is when your unit dies or the electricity goes out (no generator or batteries) and you need to look elsewhere for heat.

I was told the annual mini split service is important to clean it of any mold. Apparently they collect mold more so that other type of AC or heating units. IDK, just what I have been told. I have noticed the larger HVAC and Plumbing companies in this area are pushing service contracts. If you are not under contract with them they will not put you on priority if you have an emergency with the heat cutting out in the middle of winter. In other words they will take their sweet time to show up if you do not pay them the contract fee every year. Some call this extortion while others call it smart business.

28F? I have a 5 year old Rheem, far from what I'd consider a modern cold climate unit, and it still will produce 40k BTU at -10 F.

 

[pcmeiners]

"Just so people reading this are not confused. Modern heat pumps are good alone down to about 28F."
What you have been told was good 5-10 years ago, you should check your facts, or read some of the past threads from this sub forum, you are only confusing people .
My minisplits can now go down to >-26 degrees, outputting 110% of their BTU rating with no resistance heating coils, and remaining efficient at lower temperatures

"You need a backup heat source only if you have anything that will be damaged from freezing during an extended power outage."

You might want a backup heat source if you do not like condensation/rust on your tools.

 

[u3b3rg33k]

Yes it is. Gas is priced in therms and Electricity is priced in KWatt-Hours. You need to understand you have to maintain a second heat source. Weather it is gas, oil, electric base board. Gas or oil burners need maintenance and need to be replaced every 20 to 30 years. The heat pump is only good for 15 years. Not easy to predict future replacement price. I have been quoted the annual maintenance on a minisplit type of heat pump to be $250 per year per unit. I am not considering this but I know a few who had them installed and were shocked by the annual maintenance cost. There were wooed in by being Cheaper than a full central air install, and not having to deal with window AC units any longer.

Most oil burners I've seen have been in service at least that long. granted they need service, like nozzle changes, heat exchanger cleaning, etc, but I think the numbers are skewed lower by people who don't maintain their equipment.

there seems to be a lot of "FU pricing" on minisplits, both on the installation side and the servicing side. I like to ask the company's opinion of minisplits, heat pumps, etc and if they **** all over them I go elsewhere.

You know it's amazing fridges can go 20+ years and not need a thing, not even a coil vacuuming. Yet some HVAC companies seem the think certain systems need "service" 2x a year.

around here, coils need to be cleaned annually (at a minimum) after cottonwood season, if you're running the unit during that time. "it depends" is the real answer. I clean my coil with water 2-3x a year. because it's kept clean it needs very little effort to keep it that way. maybe 5 minutes.

OK maybe.

Just so people reading this are not confused. Modern heat pumps are good alone down to about 28F. This is what my HVAC guy has told me. At About that temperature the supplemental heat kicks in. So in a location where it never gets that cold, you can get away with no supplemental heat source. Back up heat is something else. It is when your unit dies or the electricity goes out (no generator or batteries) and you need to look elsewhere for heat.

I was told the annual mini split service is important to clean it of any mold. Apparently they collect mold more so that other type of AC or heating units. IDK, just what I have been told. I have noticed the larger HVAC and Plumbing companies in this area are pushing service contracts. If you are not under contract with them they will not put you on priority if you have an emergency with the heat cutting out in the middle of winter. In other words they will take their sweet time to show up if you do not pay them the contract fee every year. Some call this extortion while others call it smart business.

Old Fridges seem to last for almost ever. I have a 40 yr old Admiral that is still working. Some of the plastic parts are cracking but it still keeps everything cold. It uses R12.
Fridges bought in the past 5 years have had a lot of quality issues and defects in manufacturing. This is anecdotal from my conversations with a lot of people who have purchased Fridges in this time frame. Lots of warranty calls and things like door handles breaking. My Real Estate agent has confirmed this with me and has said to stay away from certain brands that use to be thought of as quality.

gonna disagree with that.

this disinformation (from your HVAC guy) is likely down to sizing calcs. "well you got a 100k furnace (oversized) and a 3ton heat pump, so that means it can't heat when it's cold outside." but with no maths to back it up. my house (1950s construction) doesn't go past 30kBTU required to heat until it's under 10F outside.

how low can your heat pump go is ENTIRELY based on heat loss at X temp, and capacity at X temp. if capacity >= heat loss, it works.

if capacity < heat loss, you need to supplement. Most people's understanding of heat loss really isn't there.

old fridges can seem to last longer, but I did the math on a 1990s fridge that we had with kill-a-watt data over a month of runtime (fridge died in 2022) and a newer fridge, and the old fridge cost DOUBLE to operate. the price difference would've paid for multiple upgrades over its lifetime.

 

[nbpt100]

"Just so people reading this are not confused. Modern heat pumps are good alone down to about 28F."
What you have been told was good 5-10 years ago, you should check your facts, or read some of the past threads from this sub forum, you are only confusing people .
My minisplits can now go down to >-26 degrees, outputting 110% of their BTU rating with no resistance heating coils, and remaining efficient at lower temperatures

"You need a backup heat source only if you have anything that will be damaged from freezing during an extended power outage."

You might want a backup heat source if you do not like condensation/rust on your tools.

OK who makes that one? thanks

 

[pcmeiners]

My post #12 of this thread has a link to the Fujitsu low temp units I referred to.

 

[justler]

Recently went through this and I settled on Senville 18K and 33K BTU Aura series single head units (Arctic, -22F). I live in Maryland so we see pretty low temps in the winter (lower than NC) but it's unusual to get below 15F.

Total equipment cost:

$4,165.74

1x SENA/18HF 18K Unit
1x SENA/33HF 33K Unit
2x Stands
2x Outdoor lineset covers

Space is 30x60 with a little under a third split off for an office.

Mitsubishi, Fujitsu, Carrier, LG, (Insert "brand name") contractor quotes installed were between 3-4x the cost across multiple contractors. I can replace the Senville units 3-4x if I had to (I won't have to) and still not come close to the cost of going with a brand name, contractor installed unit. I'll do the yearly maintenance myself with a minisplit bag, viper pack cleaners, check superheat, subcool and use borrowed tools (I do it on my ducted systems currently).

I have solar panels so I don't really care if the units aren't in absolute peak performance range due to outside temp. I am also familiar with vendor data sheets and that pretty much everyone lies on them across just about every industry on their product's performance in some way. Even if the Senville units perform at 75% of what they say I'm still way ahead of the brand name options.

My install is simple. Inside unit goes out the wall (1ft) and straight down the wall (6ft). Condensers sits on pad with 12" stand. Doesn't get any simpler. Friend has a vacuum pump, gauge set and flare tool I'm borrowing. How these companies can even quote prices like they do with a straight face is just amazing... I own a business, understand overhead, insurance, liability, truck rolls, paying for experience but the margins are just insane. The quotes I got are not "I don't want to do this" quotes either, they want to start soon, follow up and are obviously hungry for the business.

If by some miracle the Senville units don't work below even 32F (I **** you not, a couple of the contractors said heat pumps don't work below 32), I'll just buy and install the pipe for the Osburn stove I have sitting here. The HVAC industry has made many customers like me who would just like to not get completely screwed and the only way I can do this is roll the dice on a contractor or just do it myself. I can do it myself now because a lot of the knowledge is more publicly available and tools are less expensive than they used to be.

 

[nbpt100]

Most oil burners I've seen have been in service at least that long. granted they need service, like nozzle changes, heat exchanger cleaning, etc, but I think the numbers are skewed lower by people who don't maintain their equipment.

there seems to be a lot of "FU pricing" on minisplits, both on the installation side and the servicing side. I like to ask the company's opinion of minisplits, heat pumps, etc and if they **** all over them I go elsewhere.

around here, coils need to be cleaned annually (at a minimum) after cottonwood season, if you're running the unit during that time. "it depends" is the real answer. I clean my coil with water 2-3x a year. because it's kept clean it needs very little effort to keep it that way. maybe 5 minutes.

gonna disagree with that.

this disinformation (from your HVAC guy) is likely down to sizing calcs. "well you got a 100k furnace (oversized) and a 3ton heat pump, so that means it can't heat when it's cold outside." but with no maths to back it up. my house (1950s construction) doesn't go past 30kBTU required to heat until it's under 10F outside.

how low can your heat pump go is ENTIRELY based on heat loss at X temp, and capacity at X temp. if capacity >= heat loss, it works.

if capacity < heat loss, you need to supplement. Most people's understanding of heat loss really isn't there.

old fridges can seem to last longer, but I did the math on a 1990s fridge that we had with kill-a-watt data over a month of runtime (fridge died in 2022) and a newer fridge, and the old fridge cost DOUBLE to operate. the price difference would've paid for multiple upgrades over its lifetime.

Most of the heat pump info I have gotten is from two HVAC contractors and a guy from MASS SAVE which is an energy conservation group in my state that is mostly funded by the power companies. The 2 contractors said you need supplemental heat below about 28F. They installs Mitsubishi and some others. Are they just being conservative? Do they only want to install the less expensive less efficient units? Are they behind on keeping up? IDK.??? I assume they get their info from the distributers and manufacturers.

One sized a 2.5 ton ac unit and a 3 ton heat pump as an option, doesn't that suggest the heating requires a bigger load.? if so, then aren't you risking going way too large on the cooling end.? Isn't going over sized on cooling going to cause the unit to cycle too frequently.? Perhaps he is trying to balance that?

I have not spoken with either one of these guys recently but I have a lot more questions.

I assume everyone here is talking about air units and not geothermal or water? I do not believe anyone has said, they have a geothermal unit which are the most efficient and most expensive to install.

 

[P0234]

The 2 contractors said you need supplemental heat below about 28F. They installs Mitsubishi and some others. Are they just being conservative? Do they only want to install the less expensive less efficient units? Are they behind on keeping up? IDK.??? I assume they get their info from the distributers and manufacturers.

It is nice to have supplemental heat for two reasons, the HP dies and you still have a source of heat and when its in defrost mode (for a very short time), you don't get blasted with cold air from the vents. But you do NOT need it to keep your house heated under normal circumstances.

As mentioned above numerous times, the industry is riddled with crackpots. There are some really good techs, but finding those is dependent on you. You can either chance it or do your own research, all the info is out there.

 

[pcmeiners]

"Do they only want to install the less expensive less efficient units?"

Damn right,. at least the ones you talk to do. If you want a good unit, research yourself or else your talking to foxes guarding the hen houses. At this time there is no reason to buy a unit that will not provide heat to the low temperatures in your area without resistance coils, ......unless it is due to greed. As to the Federal/state government agencies involved in this industry, they are highly lobbied, and look the other way.

In this this thread we are talking about air units. Geo is more expensive and has costly requirements, a lot of land or wells.

 

[u3b3rg33k]

Most of the heat pump info I have gotten is from two HVAC contractors and a guy from MASS SAVE which is an energy conservation group in my state that is mostly funded by the power companies. The 2 contractors said you need supplemental heat below about 28F. They installs Mitsubishi and some others. Are they just being conservative? Do they only want to install the less expensive less efficient units? Are they behind on keeping up? IDK.??? I assume they get their info from the distributers and manufacturers.

One sized a 2.5 ton ac unit and a 3 ton heat pump as an option, doesn't that suggest the heating requires a bigger load.? if so, then aren't you risking going way too large on the cooling end.? Isn't going over sized on cooling going to cause the unit to cycle too frequently.? Perhaps he is trying to balance that?

I have not spoken with either one of these guys recently but I have a lot more questions.

I assume everyone here is talking about air units and not geothermal or water? I do not believe anyone has said, they have a geothermal unit which are the most efficient and most expensive to install.

loads depend on where you live, and the weather. Mass probably has higher heating loads than cooling, but that depends on where the house is and what loads are on it.

one really nice thing about the inverter units, is that you can stage them by airflow. almost ALL of them run stage 1 purely on sensors. meaning it will make a cold/hot indoor coil and hold a temperature, without regard to what's happening outside.

this means that if your cooling loads are low, you don't ice up the coil, and if it's really cold outside, you still have nice warm air coming out of the vents. the compressor flow/power is adjusted to meet the demand presented to it (within its limits).

oversizing a single stage unit can result in unhappy customers. inverter units are much more flexible, especially if you have an air handler that can be tuned on a per stage/function basis. mine can be set for cool 1,2 and heat 1,2 each individually.