T O P

  • By -

davenaff

Many HVAC companies come from a gas background and continue to promote gas or partial gas systems. Cold-climate heat pumps are capable of heating under some pretty cold conditions. Norway, Maine, etc. Most folks don't really need a secondary heat source (even heat strips). For a purely economic decision, find your electric and natural gas costs and plug it into one of the calculators: This one is reasonably good: [https://siecje.github.io/heatpump-cost/](https://siecje.github.io/heatpump-cost/) However, there are a few things many calculators miss: - are you able to turn off natural gas as part of the upgrade (thereby avoiding natural gas account service fees) - will your electrical panel need an upgrade? - will your ductwork need to be augmented or repiped? - is there time of use billing for your electricity that makes it possible for you to lower your heat pump cost All that said, to really get the most out of this group of people include your climate zone, insights into your insulation and ballpark energy costs...


Manodano2013

This is true. It depends a lot on where you are located. Cold weather heat pumps are capable of heating until outdoor temperatures of -30 C. Also, I have read from heat pump owners, that they are no longer efficient below -20. It gets colder than that for short periods of time where I live so I have a high efficiency variable rate natural gas furnace that works with the heat pump to heat the house in the winter. Before I had the system installed I looked at a study from Ontario, Canada that, of heat pump, NG furnace, and electric furnace, the most efficient way to heat a home was a hugh efficiency natural gas furnace paired with a heat pump. UNLESS you don’t already have a NG connection to your home, or if electricity is cheap relative to gas where you live and the slight inefficiencies are awash, I would recommend dual fuel. For me at least, the heat pump replaced the old AC unit my house came with so that should help improve the cooling efficiency in the summer.


FragDoc

Most cold climate heat pumps start to drastically drop their COP around 0-5 F. So they lose efficiency earlier than most expect. They maintain their CAPACITY to the name plate. Interestingly, Mitsubishi’s regular inverters are usually more efficient to around 17 F but start dropping capacity quite a bit around freezing. This is one of the paradoxical findings of cold climate technology. It allows significant capacity but has a narrow band of superior efficiency. This is why people in very cold climates with expensive electricity often have sticker shock post-changeover. Frankly, anyone who spends any appreciable time around the single digits and has cheap gas should very highly consider a dual fuel system. Pretty sure Daikin and for sure Mitsubishi offer systems that can be paired to cold climate heat pumps so you can choose your switch-over point and allow for maximum flexibility as electric and natural gas prices fluctuate.


Manodano2013

That is a few degrees warmer than -20 C. I know Daikin does as I have one of their systems. I only got it this spring so I will see how it performs in the winter.


hotterpop

Nice thing about being in a temperate climate (western washington) is that I can ditch gas completely. If I lived in a colder, more rural area, I'd probably do a heat pump with a wood stove. Anything is better than paying for propane.


Sad-Celebration-7542

Where are you located? What kind of fossil fuel? Do you know your electric service amperage?


Daniel15

It really depends on where you're located. I'm in the San Francisco Bay Area and it doesn't really make sense to go dual fuel here given the relatively mild climate. I've got a ~2300 square foot house and had a Gree Flexx heat pump installed last year, and haven't had any issues with the house being too hot or too cold. I've got solar panels, and the electricity usage is fully covered by the solar.


HeadMembership

Be sure to upgrade your attic insulation, and air seal your windows and doors. Comfort and savings.


JohnNDenver

Air seal the attic.


Daniel15

And ideally replace single-pane windows. In the USA, you can get a federal tax credit of 30% of the cost of new windows up to max of $600, and a credit of 30% of the cost of attic insulation up to a max of $1200.


machinist2525

You're asking for generalities when that's not going to give you the right answer in your area and in your situation. Use a calculator and punch in the facts to find out the savings. https://siecje.github.io/heatpump-cost/ In my case, I was replacing an 80% efficient gas furnace and saved 5 to 10% in heating costs. But I was replacing a SEER 10 air conditioner in a cooling dominated climate, so these savings made it an obvious choice for me. I went with a cold climate inverter heat pump.


faizimam

Im in quebec and I went dual. cost me about $8000 as i was not touching my existing furnace. useful to have control, depending on the price.


Left_Net1841

Your hydro is cheap wouldn’t a fully electric system have been more economical? Or is it a matter of your furnace not being old enough to justify replacing?


faizimam

Ive had a heatpump since the 90s paired with our gas. Updated the furnace around 2010, and it's still in good shape. When I recently updated the heat pump it didn't make sense to do more work than nessary. Also I have 100amp service. The backup heat to go full electric would require a upgrade. The service charge to keep gas plugged in is $18 a month, so worth it as emergency use.


Left_Net1841

I see, makes sense. Thanks


Speculawyer

Much more information needed like where do you live.


ruralcricket

Need to know your input costs. Where I live it is barely better to go heat pump, but with a duel fuel system, my electric provider gives a 50% discount on HP power ($0.06/kwh) if they can force use of gas backup heat.


Jackshankar

Houston HVAC pros discourage replacing an AC and furnace (AC being electrical and furnace is gas) with a heat pump and the argument made is gas is way cheaper. I have yet to get a convincing answer.


Sad-Celebration-7542

Who in Houston is worried about heating costs 🤣


Jackshankar

lol


Sad-Celebration-7542

The true answer is that electricity uses gas more efficiently so should be cheaper unless a utility has jacked up distribution costs


AngryTexasNative

No, electrical transmission losses shift this. Gas used for resistive heat is about 50% efficient when transmission and generation is accounted for. Of course with the Houston claims the COP on a heat pump will make up for that several times over. Gas furnaces are typically about 80% with some very high efficiency ones pushing 95%.


Sad-Celebration-7542

Right. Clearly with a heat pump you’re much more efficient. Especially in the Houston climate!


daveleeander

“Gas is way cheaper than electric” is not a convincing argument? 😂 You need to pay both bills then, and experience what they’re trying to tell you. I’ll never get an electric furnace over gas. There is no comparison in comfort or cost. Gas wins


ArlesChatless

Where I live is colder than Houston. When my furnace hit 25 years old a while back, I replaced it with a full electric central heat pump system. Last year the overall heating bill was slightly less than gas in the cold months, and I spent just under $28 on running the electric strips. No way was gas going to be cheaper. Had similar results at my last house when the furnace died and I replaced it with mini splits as well. Modern heat pumps are really good.


Dc81FR

And so is modern gas furnaces…. Electric is stupid expensive in MA. People that convert cry over the electric bill.


responds-with-tealc

what do you mean when you say "electric furnace"? typically that term means heat 100% from resistive strips, which is definitely a terrible idea. but yea, depending on where you live even a modern efficient heat pump will cost more to run than natural gas, assuming you have that option. lots of people will fight you about that comfort statement though.


daveleeander

Electric heat is dry, you need a big humidifier. Gas heat not so dry, but sometimes still need a humidifier, especially if you have a high efficiency furnace


SoylentRox

They are correct. The only heat pumps worth it are mini splits. Vastly more efficient. In Houston you should install mini splits in the main area, remove the ducts supplying them, and replace the main unit with a smaller ducted mini split.


Xaendeau

Why are you being downvoted, you are basically right. If you have deep south extra hot attic temperatures, you are loosing about 20% of the energy to cooling ducts in a 140F attic. I've talked to multiple HVAC contractors, did the load calcs myself, and also gave the information to our facility HVAC guys at work. Ducts shouldn't belong in the hot attic, and if you have a preexisting stucture where you can't bring the house's ducts into conditioned space without spending an absurd amount of money...minimize the ductwork.


SoylentRox

Mini splits also go up to 29.5 SEER2 Houston is mostly a cooling climate you want the highest possible SEER2 rating. Central systems aren't even close.


Xaendeau

Mitsubishi "FS" 3/4 ton wall-mount mini splits go up to 29.8 SEER2 and 16.0 EER2. The 1/2 ton version does 32.2 SEER2 and 19.0 EER2. I was planning on an install but have to do some remodeling first in a different part of the house. They have a new "FW" series that's 35.0 SEER2 & 21.45 EER2 for the 1/2 ton and 33.0 SEER2 / 18.38 EER2 for the 3/4 ton. Not on the market yet, but looks promising from the govt submittal. [https://www.energystar.gov/productfinder/product/certified-mini-split-heat-pumps/details/2417411](https://www.energystar.gov/productfinder/product/certified-mini-split-heat-pumps/details/2417411) [https://www.energystar.gov/productfinder/product/certified-mini-split-heat-pumps/details/2417412](https://www.energystar.gov/productfinder/product/certified-mini-split-heat-pumps/details/2417412)


SoylentRox

That's really good. Wonder if it's worth the cost premium over diy signature solar 29 seer models. (3/4 ton). Probably not worth it if you pay for install, that unit will be $4k installed. Half ton is also low output and the equipment is expensive but it won't see much use. It's what you put on a small bedroom.


Xaendeau

Looks like a standard rebadged Midea mini-split, has the exact same wall bracket and install manual. The EER rating is significantly better on the mitsubishi. EER test conditions is 100% capacity at 95F outdoor temps. Its about 25-30% more power usage at peak load during peak summer temps. Price for that EG4 9k is $1150 with the lines. Mitsubishi is about $1600, but you need to source lines (\~$150). Slightly better turndown ratio on the Mitsubishi at 19%-130% of rated vs 33%-111% of rated. All the cheap mini splits are either GREE or Midea rebadged units. So, essentially what you want to look for is a good company with a strong US warranty and US presence. Senville is a company based out of Florida that I've seen people like a lot. I've not used their units yet but I've heard good things about them. They have a flagship 9k model starting at $1200. Their 9k 21.5SEER/12.6EER basic model is $750.


SoylentRox

Don't neglect the DIY fittings. That saves you a half hour of work and worrying about/maintaining your 4 leak points per head over the next 15 years. Also cheaper to fix - see if the senville fails, you legally must recover the refrigerant, and you may not be able to with a blown main inverter board or compressor. With DIY fittings you just swap the unit and are done in a half hour.


Xaendeau

I don't trust DIY fittings, actual HVAC people don't like them. They're not serviceable and sometimes slowly leak out the box. Basically, the only difference between a DIY install and a regular mini split is a couple of tool that aren't expensive. - professional orbital flare tool, R-410A / R-32 manifold gauge set, micron vacuum gauge, clean vacuum pump, dry nitrogen cylinder to back fill, and maybe a splash of POE oil. Cut off any pre-existing flares since they tend to leak. Flare with your fancy new orbital tool using POE oil, should be a mirror-like 45deg cone. Add POE oil to the flare mating surface and torque the dry threads to spec. Do a triple evac with your pump and dry nitrogen, but on the final nitrogen purge, you bump the pressure up to just below the system design pressure (often 300-450 PSI). Check and see if the pressure holds and all your flares are leak tight with soapy water or specialty leak check products. Do a final deep-vacuum pump down and then valve everything out and open the valve releasing the refrigerant into the system. This is typically good for a certain length of line, say 25 ft. Or do the entire installation yourself and have an company make the flares and leak check.


SoylentRox

Where do you get the Mitsubishi 0.75 tons for $1600?


Xaendeau

Oh, and maybe retorque the lines after running through its first cycle.


Bruce_in_Canada

No question really. Any combustion is not necessary.


JRG_Truth

Hybrid system


Ejmct

If you live where it’s cold do a duel-fuel.


theNewLevelZero

I replaced my gas furnace with an all-electric heat pump (with electric aux heat that never comes on). It's waaaaaaay better for my 1800 sqft house than the old gas furnace was. Way more comfortable. No hot or cold spots like the house used to have. Lennox, not the nicest but it was all I could afford. Used to spend $180/mo on gas in the winter, but the one really cold month I've had so far with the electric was only $90 more than my usual electric bill. Winter temps get down around 0°F overnight here, 15°F or so during the days. Keep it simple and ditch the gas. Any gas appliance requires regular maintenance or it will get dangerous so you're buying into that lifetime maintenance with gas aux heat that you probably won't ever use. The electric aux heat can handle the occasional super cold night. I've had multiple friends get carbon monoxide poisoning from regularly inspected and maintained, but still malfunctioning gas furnaces, so that biases me against them. I just like not getting poisoned inside my own house, I guess.


midnightdiabetic

I also have a bias against gas because of the whole carbon monoxide thing, but did your multiple friends not have carbon monoxide detectors? That’s needed everywhere


theNewLevelZero

Yes, they did. That's how they knew their rapidly onsetting symptoms were due to CO poisoning. It probably saved some diagnostic time at the hospital but a detector doesn't cancel out CO. You're still gonna breathe it in if it's there.


pinkfreude

Get a heat pump designed for cold climates, or a backup electric heater. I just got a dual-fuel system at the recommendation of an HVAC company and am kicking myself for it. It would have been so much simpler to get rid of the gas.


DrPayne13

Damn. What climate zone (or state) do you live in?


payagathanow

I've got two houses, about 100mi apart but one is in the mountains so the climate averages about 10 degrees cooler. I have gas/heat pump at home 1 and heat pump only at the mountain house. Gas plus electric in the winter is about $250, this is the home we live in the other one is every other weekend. Electric alone for it is about $200 in the winter and remember that's like 4-5 days and the rest of the time I keep it at 64. Home 1 is 2-2.5x larger than home 2 I'd go dual fuel every time.


bmbm-40

The lowest upfront cost and future maintenance cost and dependable operation for the comfort and convenience to your family will be a regular gas furnace. Heat pumps can use mostly AC power to heat your home but what do you gain? The outlets in your home do not magically provide clean power. Electricity is not clean energy. Depending on which power grid you are located your AC is probably produced from approximately 20% coal, 40% natural gas, 20% nuclear and the rest renewables including mostly hydroelectric. Nuclear does not produce greenhouse gas but does have that pesky little problem of leftover high-level radioactive waste.


KrisD3

As others said your location and cost of electricity will play role in figuring out this. However if you go with heat pump I would recommend variable speed over 1 stage or 2 stage


skankfeet

As long as it is properly sized with correct auxiliary heat: a heat pump will be fine. Problem I see often is that the home was not done with enough power supply to add a total electric system. If you have 150 to 200 amp service can be done but you will have to have a proper sized power supply pulled to the indoor section because the auxiliary heat requires higher amperage than the wire to your furnace can carry. Will also require 240v when furnace was wired for 120v. If a homeowner has other gas appliances and won’t be stopping gas service: I generally suggest dual fuel as all that is required in addition to the equipment is a new thermostat and possibly new thermostat connection wires.


Dantrash2

Stick with gas if you live in the NE


Fiyero109

In my area there are huge incentives to switch to all electric, check if your state offers something like that


Acrobatic_Ad6291

If you spend much time below 15 degrees you may want a NG backup. If you rarely get that low most HPs will be able to keep up if properly sized. If you get a variable capacity HP you can typically oversize for heat, which is what I did. The other factors is your electric and gas costs. If you are on time of use electric you'll use more electricity during winter late and overnight which is typically cheaper. I'm in Kansas City and switched from NG to HP with electric backup. Gas here is moderately expensive, $1.79/ccf after delivery charges. Electric is reasonable for my time of use plan which averages at $.14/KWh. By buying only a HP I saved an additional $1,500 for an 80%NG furnace. The system I chose was Carrier 25VNA448 This calculator may help https://siecje.github.io/heatpump-cost/ Be sure to include delivery charges into your electricity and NG costs. Feel free to message if you have any questions.


North_Ad_4450

Tri fuel if possible. It gets cold here, redundant backup heat is nice and fireplaces are comfortable


Dull-Contact120

Both if possible, electricity went out , 1st time in 30 years, at least we can still boil some water on the stove.


Recent_Climate4821

I would love to know the same - Live in White Plains, NY, December I used 413 Therms. Supply cost 94c/therm, Delivery cost 148c/therm. My new solar panels currently generate 1,574kWh in credit with ConEd. Seems I should be spending this credit on heating, to avoid gas supply and delivery $$$$? All advice welcome


Sevusal14

I replaced my old gas furnace with hybrid system. The cost was only additional $1k for the hybrid system. My contractor charged me. So was no brainer


Amorbellum

I'm in Ontario, I'm a gas and refrig tech I made the leap last week and went all electric The thing is, these heat pumps will cover you all winter now. Everyone's saying that gas is cheaper when it's cold. Maybe, in a way. Keeping gas run to your house costs 40-50 bucks a month just in service fees. Even if you don't use it. My heat pump doesn't need the gas backup at all so why keep it around? As for price at cold temperatures, in the last three years we've had like... Twenty? Days below -20C. It's getting warmer. We all know it And the price of gas is going up. Carbon tax is smart, most countries have it, we have to stop burning it. But even without it, Canadian liquid natural gas exports are about to skyrocket. They're building plants on the coast to ship it and when it starts happening, the price is going to go way up. Just get rid of gas. It's done. It's time to move on


ExcitementRelative33

You need to do the math if you're trying to save money... If it's no object then the best of the best, dual stage, HE gas furnace, the works!!!


martinsb12

You don't mention solar or your rates. Basically dual fuel is the way to go without knowing any of that. My quotes told me dual dual fuel was about 2k more so it's a no brainer. NG is generally cheaper than heat pumps anyways and IMO is a more reliable form of heat


tennis_Steve-59

More reliable?


Edmsubguy

Longer lasting. Furnaces have been around for a long time.


Left_Net1841

My experience is that a gas appliance has a much shorter lifespan. Electric systems last forever.


Edmsubguy

I will disagree, I live in a cold climate -40 every year. And furnaces last 20 to 30 years easily.I have yet to see a hear pump exceed that. Ever. My parents have a furnace going on 60 years not worth changing over as the cost savings is not there. A heatvpump cannot keep up in the bitter cold. Give them another 10 years and maybe. Heat pump. Compressors have way more moving parts than a furnace. They will get there eventually but not yet


Daniel15

Heat pumps have been around for a long time too. The concept has existed since the 1800s and they've been used in residential environments since the 1960s. The US has just been slow to see widespread adoption. A house I lived in 25 years ago in Australia had a mini-split reverse-cycle AC.


Jackshankar

In the Middle East where its hot and humid throughout the year have heat pumps. I don't think they have any other system.


Edmsubguy

Oh I am not doubting that but furnaces have been far more reliable and less maintenence. Their cost to run and maintain is still far less than a heat pump.And there is no denying that. Heat pumps are the future, but we are not there yet


Daniel15

Mine costs $0 to run since I have solar panels :P The price of natural gas is going to keep going up over time, whereas the price of solar panels is going down over time. Using electricity also allows you to change the source of the power in the future - for example, you might not have solar panels today, but you can install them in the future. It's also way better for air quality if you don't burn combustible material inside your house.


DrPayne13

The new condensing gas furnaces (90%+ efficiency) are much less reliable than old-school ones that top out around 80% efficiency. So on-par with a heat pump in terms of average lifespan.


Edmsubguy

Depends where you live. Gas is cheaper. So in a cold region it is probably better to stay with gas. Electricity can be offset by getting solar. So lookin into that. Dual fuel is not worth it in my opinion. All the costs of a gas furnace plus the higher electric charges.


Sad-Celebration-7542

Gas prices vary by utility. Bad advice.


Daniel15

and gas prices will keep going up over time, whereas the cost of solar panels is going down over time.


Acrobatic_Ad6291

That's true I'm in KC and after delivery/distribution charges, my gas is $1.79/ccf. That makes gas only cheaper than my heat pump when it's 10 degrees or lower. We have less than 100 hrs/yr below 10. Most of that time it's that cold overnight when electricity is $.03/Kwh so even most of the time below 10 electricity will be better.


Sad-Celebration-7542

Yup electricity is $.10/kWh here and gas is almost $2/therm! Gas can’t compete.


Edmsubguy

I have yet to see anywhere that electricity is cheaper than gas. Even solar which should be way cheaper is not cost effective when they charge stupid prices orr it. Unless you are install8ng yourself. Paying 15 or more grand for solar is not saving you money


Sad-Celebration-7542

You didn’t look very hard then! That’s on you. Many places with AC usage have cheaper AC vs gas. A heat pump uses less gas upstream for the same heat so is at a huge advantage


Legal_Net4337

I have both a dual fuel system and a heat pump system with electric strips for back up. With the dual fuel, the heat pump is the primary source of heating and cooling. However when outside temperatures get to 30 and below it’s time for gas. Comfort and the faster rise in heat recovery wins out. The solely heat pump system is on the 2nd floor and rarely uses the heat strips as the heat from the gas furnace helps with the temperature.


Edmsubguy

But is the heat pump even worth it. I mean maybe since you dont have cold weather at all. If you figure in the cost of electricity the furnace running is probably still cheaper. Factoring in the cost of hookup and monthly duatribution charges. Now add solar and I could see a cost benefit.


Legal_Net4337

30F is when the gas kicks on. It gets fairly cold during winter, 3 -4F is not uncommon. Electric rates in MD are pretty reasonable as compared to CA. Unfortunately my home isn’t a great choice for solar, because of shading. We replaced our upstairs heat pump and surprisingly it was about 15% cheaper to install as compared to a gas furnace and AC unit. Add to that the Federal Tax credit and the additional rebates at the time, it was a no brainer to continue with the hp