Comparing energy usage: 1 year of gas heat vs. 2 years of heat pump

ChrisJ

Hot_water_fan said:

It’s cold there! Long shoulder seasons would help the COP. I won’t run the numbers but obviously there are some places where hybrid systems make good sense. It’s not a binary, we must remember that. 

I can agree with that.

fentonc

The closest place I could find hourly bin data for on NOAA's website was Sandstone, MN - 200 miles south, but still pretty cold (low of -20F or so during this period). So for sandstone, MN in January and February this year there's been something like 22 hours below -13F and about 700 hours warmer than 15F. Just switching to modulating equipment that wasn't way oversized would go a long way for many people, but I bet there's a lot of boilers that look like mine with seasonal average efficiencies less than 50%.

ChrisJ

fentonc said:

The closest place I could find hourly bin data for on NOAA's website was Sandstone, MN - 200 miles south, but still pretty cold (low of -20F or so during this period). So for sandstone, MN in January and February this year there's been something like 22 hours below -13F and about 700 hours warmer than 15F. Just switching to modulating equipment that wasn't way oversized would go a long way for many people, but I bet there's a lot of boilers that look like mine with seasonal average efficiencies less than 50%.

I'm not positive but I think 23 seemed to be a warm year for that area.

Mad Dog_2

Go Colts!! They'll always be The Baltimore Colts to me....Nothing against the Ravens..Go Ray and Siragusa! Mad Dog

Mad Dog_2

Great debate guys.  The longevity of equipment carries a HEAVY weight in my book.  The less you have to worry about, a vital, life system like heat, the better!  Aside from financial cost, EVERY time you need to hire a new contractor, can be very stressful  and unpredictable experience to the layman.  Not all installers are equal- we know that well.   My two cents:  I spent the first 12 years of my life with scorched air and central AC. The AC was great..the Scorched air??  It got the job done (we never got 🥶 Frostbite living right on Jamaica Bay) but is was like the difference between having a sheet on you instead of a blanket....It was better than nothing, but lacked the swaddling warmth of a blankee. I then lived with 17 years of A HW monoflow system with Convectors...much better...for the last 22 years, I've had the BEST heat of all....The Steam.  First house..2 furnasties in 12 yrs...Second House ..3 boilers in 76 years (History of the house was oil-HW- 28 yrs ((Change by fuel choice not necessity)), 32 years nat gas conventional gas/HW atmospheric boiler (Federal), third boiler (also changed by choice, not necessity- nothing wrong w boiler.  17 years HW convectors, Buderus Panel rads for basement and staple up radiant in den.  All-powered by Buderus GB-142 Wall Hung Mod Con.  It was nice having all those emitter options and house was always warm and toasty.  Current home 1900 Country Victorian Farmhouse.  Coal pot belly  Stoves on each floor 1900-1928.  One pipe Oil/Steam with free-standing Cast Iron Rads 1928-2000 -very toasty.  2000-2023 Change by choice to nat gas.  New - from scratch -  antique one and two pipe steam Vapor system AND radiant in mud for two bathrooms, and basement slab with bathroom on radiant.  I love 💘 oil, but the Gas Utility at the time made me a Don Corleone-Style Offer...two "FREE" Burnham Boilers, one for the Steam and a small Series 2 HW boiler JUST for the radiant.  The House looks warm and cozy AND IT IS...The Siamese Cats loved the radiant as much as much as my  youngest daughter who studies on master bath floor and holds court in there for hours on end with her freinds on the phone!  For the last 22 years, I have warmed my clothes and dried out my wet work clothes and kids hats and mittens on my Cast Iron Darlings.  Did I mention they look like Raquel Welch compared to some bland, plain Jane....My two Cents. Mad Dog 🐕 

archibald tuttle

Hot_water_fan said:

No, fortunately $.1457/kwh is my all-in rate, which is about average for the US. New England has eye watering electricity rates while we don't, and I suspect it's because of our high AC penetration. My transmission and delivery rate is $.05 $.038/kwh - a lot of juice flows across the wires, so utilization is high.

thanks for playing, but no, in new york and new england 'delivery' charges are where they hide the enormous policy mistakes made by our legislatures to force us to buy 'cheap' renewable power, you know the stuff where there is no fuel cost. our 'delivery' costs weren't significantly different from yours until they started pushing that nonsense. and then, because they made it cost so much, the middle class ratepayers have to cover the bills for the lower quintile who can't afford it, etc., etc., etc.

I think this technology is maturing to the point of competitive viability in some climate zones and gas vs. electric cost splits (although I thing R410A was another stupid government forced decision, we would be just fine and just as efficient and better maintained with R22 for the time being but I digress–on my favorite threadjacking topic). It's on the margin in coastal zone 5 (southern new england) because of comparative gas and electricity prices as well as added defrosting loads. Looks just OK when COP is actually 3 but what gross degree days doesn't tell you is the size of the departure on any given day, and the lower that outdoor temp the lower the COP (and the higher the humidity even when temps are above freezing the more defrosting which cuts into COP). My guess is you didn't have too many days when it was 8 degrees. you don't mention your location or climate zone, but the priorization of air con suggests mid atlantic or carolinas . . .?

On the other hand, where air con is installed (minisplit or forced air), heat pump is beginning to be a no brainer since so many units means the added cost vs air con only unit disappears and you just need better controls with outdoor temperature and humidity cues to call your existing backup when COP drops below 3. Wouldn't hurt to have better measured COP outputs from these electric units to aid in that process but I get the feeling the heat pump manufacturers aren't big on letting on how much below nameplate high efficiencies the things run. Even onboard measurements would be surrogates (like circulators that estimate flow vias amerage and rotor speed) but would be help offer better cost decisions.

Again, if one presumes they are going to have AC, I agree that comparative install, equipment life and maintenance costs are somewhat less important. The only thing I haven't seen yet is if you can assume that an AC only or AC and shoulder heat only heat pump would last longer and/or need less maintenance because of less winter hours of operation . . .

my 2¢ and hardly worth that i'm sure as you spend several nickels worth of time reading it. :-)

brian

Hot_water_fan

thanks for playing, but no, in new york and new england 'delivery' charges are where they hide the enormous policy mistakes made by our legislatures to force us to buy 'cheap' renewable power, you know the stuff where there is no fuel cost. our 'delivery' costs weren't significantly different from yours until they started pushing that nonsense. and then, because they made it cost so much, the middle class ratepayers have to cover the bills for the lower quintile who can't afford it, etc., etc., etc.

@archibald tuttle , can you show evidence of this? PJM also has renewables, but with delivery charges significantly less, so I'd like to see what explains the gap. ERCOT has very high renewables too - cheap rates as well.

On the other hand, where air con is installed (minisplit or forced air), heat pump is beginning to be a no brainer since so many units means the added cost vs air con only unit disappears and you just need better controls with outdoor temperature and humidity cues to call your existing backup when COP drops below 3. Wouldn't hurt to have better measured COP outputs from these electric units to aid in that process but I get the feeling the heat pump manufacturers aren't big on letting on how much below nameplate high efficiencies the things run. Even onboard measurements would be surrogates (like circulators that estimate flow vias amerage and rotor speed) but would be help offer better cost decisions.

I've seen 90% of US homes have AC, so agreed. Manufacturers should study field efficiency - heat pump and boiler manufacturers both.

The only thing I haven't seen yet is if you can assume that an AC only or AC and shoulder heat only heat pump would last longer and/or need less maintenance because of less winter hours of operation . . .

Good point - I've pondered this too. One thing to consider would be the AC lifespan in say Florida vs. Connecticut. If the operating hours actually matter, I'd expect the Florida AC to last...a year or two assuming it runs probably 10-20x more annual hours? But they last longer.

Looks just OK when COP is actually 3 but what gross degree days doesn't tell you is the size of the departure on any given day, and the lower that outdoor temp the lower the COP (and the higher the humidity even when temps are above freezing the more defrosting which cuts into COP). My guess is you didn't have too many days when it was 8 degrees. you don't mention your location or climate zone, but the priorization of air con suggests mid atlantic or carolinas . . .?

Well average HDD should give you an idea. Baltimore is the location.

Hot_water_fan

Great debate guys. The longevity of equipment carries a HEAVY weight in my book. The less you have to worry about, a vital, life system like heat, the better! Aside from financial cost, EVERY time you need to hire a new contractor, can be very stressful and unpredictable experience to the layman. Not all installers are equal- we know that well.

@Mad Dog_2 agreed, but we're in the minority here (obviously much more focused on equipment than the average buyer). I don't think Americans care much about equipment longevity beyond a certain point. Maybe that point is 15 years, maybe 20, I'm unsure, but I don't think it's an accident manufacturers have generally the same equipment lifespan for a given product. They could all build to last a century but they exist to get paid, not to build perfect machines.

ChrisJ

Hot_water_fan said:

Great debate guys. The longevity of equipment carries a HEAVY weight in my book. The less you have to worry about, a vital, life system like heat, the better! Aside from financial cost, EVERY time you need to hire a new contractor, can be very stressful and unpredictable experience to the layman. Not all installers are equal- we know that well.

@Mad Dog_2 agreed, but we're in the minority here (obviously much more focused on equipment than the average buyer). I don't think Americans care much about equipment longevity beyond a certain point. Maybe that point is 15 years, maybe 20, I'm unsure, but I don't think it's an accident manufacturers have generally the same equipment lifespan for a given product. They could all build to last a century but they exist to get paid, not to build perfect machines.

They try to balance cost with the shortest life span people will tolerate while keeping failures to a minimum especially in the warranty period. There's not much of a mystery there.

If one company comes out with a system that lasts 30 years but performs basically the same as one that lasts 10 years but costs twice as much very few will buy it. I bet if it's 10% more most wouldn't buy it.

Just like garbage kitchen appliances, all anyone cares about are shiny trendy looks, doesn't matter if it actually works right or lasts longer than 3 or 5 years.

Jamie Hall

At some little risk of being redundant... may I say again: our job as heating professionals, or responsible citizens, or both as the case may be, is to seek the best solution for each given heating or cooling situation that we can. Advocacy for one particular type of solution or another has no valid place in this.

lkstdl

Electric rates vary widely, even within one state. In Rochester, NY, we are paying 6¢/kWh for delivery and 8¢/kWh for supply (including taxes).

archibald tuttle

@Hot_water_fan

sorry, it is cumbersome to quote snippets although you did yeomans job. maybe there is a secret to copying short snippet with the quote info although the only way I have found is to quote the entire comment and then go through deleting until you have the bit you want. or to write the correct html before and after a small snippet. as was famously asked in Anything Goes when a player professed that "Liquor has never touched my lips": You know a better way? anyway, relative to my contention on high deliver costs:

"in new york and new england 'delivery' charges are where they hide the enormous policy mistakes made by our legislatures to force us to buy 'cheap' renewable power "

you asked:

"can you show evidence of this? PJM also has renewables, but with delivery charges significantly less, so I'd like to see what explains the gap. ERCOT has very high renewables too - cheap rates as well."

I should say I haven't watched New York in it's entirety as closely, although I have seen some crazy plans for NYC and its toni surburbs and long island. But I notice halfway decent rates posted for Rochester (1/2 of our total rates in Southern New England), so somehow the rotted policies of the city have not been completely foisted on those upstate. But I spend a good deal of time monitoring the Public Utilities Commission proceedings in RI and, for comparison's sake, in CT and MA.

There is, carefully and by design, no disaggregation of the delivery rate that provides the consumer with any understanding of the diversion of funds to pet legislative and NGO agendas; but we have a legislated contract for some 1 plus % of our power with Deepwater Wind (now Orsted and you'll be shocked to learn it is run by a former chief of staff to the RI governor at the time the project was approved) at guaranteed wholesale prices that commenced at 24.4¢ a kwh with an escalator so that this year the wholesale cost is about 31¢ per kwh which is actually about the total retail cost of electricity for most ratepayers all in (including deliver charges)! Other than at times of high constraint this can be as much as 6 or 7 times market wholesale cost. Because the energy cost side of the bill is controlled by an algorithmic competitive mechanism, the utility was forced to buy out the excess cost of this contract and ratepayers were forced to pay for it on the delivery side. Going on as egregious are the net metering and gross infrastructure and rates subsides to solar projects which are likewise bought down to market rates and the cost of the buydown is placed on the delivery cost. One should not conclude that all renewable energy incurs these multiples of cost over market. It depends on a particularly political finger on the scale to encourage lunacy of this scope and we just have a special talent for that in the NE.

But, to be fair, there are other public policies that show up indirectly in the retail market cost to consumers on the energy portion of the bill (where we are also much higher than the midatlantic) that can't be ignored. Because all of this 'free' renewable energy must be backed up by fossil generation but our NGO inspired regulatory environment has prevented increase in natural gas transmission while closing baseload coal and nuclear plants (both because of regulatory excesses but also because they are less well suited to load following required by the penetration of renewables) so the mid atlantic is far better off in terms of gas supply which keeps the backup generation costs low. Indeed, backup generation in New England is often run with LNG to make up for the lack of pipeline capacity. And the nutjobs who are my neighbors actually oppose liquifying the excess pipeline capacity in the summer which has placed us as competitiors in the market for shipped LNG which is now being drawn to europe to make up for what they have lost from Russia making prices high for American utilities–typically 2 to 3 times straight up natural gas pricing, and those are spot prices. My guess is that contract deals which account for the majority of the market reflect the 3 times premium. That means, ironically, our electric supply (not delivery) rates went up 50% this year while natural gas went up 15%.

But the numbskulls who make these policies and opposed liquifying gas in our industrial zones because poor people live near industrial zones, had zero understanding of the cost effectis and all they can do is complain that the increased cost of the policies they advocated are too much fort low income families must be borne by other ratepayers. The utility is quite happy to do so by adding yet more charge to the 'delivery' cost. So the middle class gets screwed every time and it is hidden in these charges because it is not detailed the extent to which affection for renewables and hostility to fossil fuel is driving these rates up and instead the utility is made the bogeyman as if this is some kind of untethered greed on their part . . . but . . . they did exact a 2.75% fee on the absurdly expensive deepwater wind project as their opposition had defeated the project at the public utilities hearings earlier as they stood up for their customers and maintained that the deepwater contract was wildly at odds with ratepayer interest and if the state really wanted to absurdly subsidize some specific project it should do so out of state and not ratepayer funds. Then they got the 2.75% sweetner and switched sides. And where does the cost of the sweetner come from . . . the ratepayers they once claimed to protect in the delivery charge!

I will concede my brief expression on the subject was potentially chip on shoulder reaction to the idea that costs of public utility infrastructure might actually be based on use and that broader year round use as with AC penetration you spoke of might be responsible for lower unit cost of delivery in your area. It would have been fair to say that this could have some impact on the mid atlantic regions where winter and summer use were better balanced, but the notable increases are brought about by stupid energy policies (and they are stupid regardless of what you think of climate and CO2. They aren't reducing CO2 notably more than the massive conversion to natural gas which is now the most hated fuel even though it contributed to a massive reduction in CO2 output. There is zero sense in commiting resources to inefficient renewable projects that we can't really afford (as evidenced by all the talk that lower quintiles can't afford the rates that this push is generating at present).

But, as @Jamie Hall points out and I agree, I'm not opposed whatsoever to trying to improve heat pump technology, install where appropriate while making careful choices in both capital, operating and maintenance that attend sensibly to the needs of each job but consistent with the reality of energy constraints (many self-imposed) in our areas. I am opposed to stupid rebates for units using a refrigerant that was orphaned from the inception of its use to try to massively move heating load to electricty when we have no conceivable renewable or affordable way of serving that load. Right now Natural gas at 80% is still cheaper than heating pumping at 3 COP! And I was equally opposed to subsidizing condensing boilers installed in circumstances where there was little likelihood they would often employ the condensing technology (and folks who could afford enough or fancy enough emitter technology to take advantage probablyh didn't actually need subsidies for the boilers! just sayin'. (Oh yeah, and where do the costs for those subsidies show up: the DELIVERY CHARGE whether electric delivery for heat pumps or natural gas delivery for 'condensing' boilers!)

archibald tuttle

While I agree with @Hot_water_fan that seasonal COP is a reasonable way to look at things on a macro scale, I don't agree that it leads to reasonable decisions on residential infrastructure that are helpful to the overall situation. Simply knowing that at exteme times you might have a little cost for resistance backup that is offset by the efficiency of operation at other times ignores the system effects of many people making that decision and expecting the utility to be able to serve resistance backup for everyone who chooses this approach and suddenly needs it. Because a lot of utility costs and undermining of reliablility are based on peaks, see, e.g., california mandating electric cars while mandating that people not charge them when it is inconvenient to the larger infrastructure of supply. (aren't we lucky in RI that we can count on California to lead the way in insanity and then we just follow along like good little coastal lap dogs a few years later.)

I also believe that the installed base of heating in the Northeast recommends that heat pumps be operated in hybrid circumstances in most cases with better controls that can track the effective COP and fuel costs and call backup when the consumer is benefitted rather than some NGO anti-carbon religion that actually pays relatively little attention to actual carbon produced by the policies it advocates. Working hard to advance this idea and the controls for such operation could also ease peak loads at exteme cold times making the system more resilient! (And you'll notice these same hacks who demand the policies that undermine resilience of utilities then complain that the very circumstance they have brought into existance that is due to fossil fuel by pointing to some frozen plant in Texas. It's not that there is zero merit to worrying whether fossil infrastructure should be resistant to temperature extremes; but the peaks of energy required–often at these times of extreme temperature–are driven by the anti-fossil fuel contingent. Even if one believed, which I don't, that these instantaneous weather patterns are driven by the buildup of CO2 emissions, no short term policy of converting heating loads to the electric grid is going to change that so it ought to be undertaken slowly and carefully.)

As to load reduction achieved by keeping reliable fossil fuel back up available in most buildings in say climate zone 4 and up, if not 3 and up, there is yin yang where the back up fuel is natural gas because of the pipeline constraints in some areas. So natural gas backup doesn't ease the transmission limits even if it lowers electric demand, albeit natural gas turbine generators have interrupts in constrained areas and must use LNG or oil backup for these times if they are contracted to generate. And, of course, all of us with LP and #2 systems ought to be onto those backup systems for high load events which also tend to be cold nights with the least renewable power available and when heat pumps would be operating at the lowest COP anyway. In this sense I don't think a focus on seasonal COP is so sensible.

Jamie Hall

My my. Well said, @archibald tuttle . Allow me to add -- and reinforce my comment -- that the problems are not with the various technologies; they all work, in the right place at the right time. The problems are with political decisions -- often driven by well concealed special interests - but however driven which fail to look at different circumstances and conditions in different places, and often are driven by single interest agendas which fail to take into account total system impacts.

Thus, for instance, a solution to a heating and air conditioning problem in, for instance, eastern Maryland, where an inch of snow can induce total panic, may not be the best solution for inland New England, where two feet of snow and 15 below might induce a half hour delay in starting school...and niether one would be of much value in guiding an intelligent policy or individual choice in, say San Diego, CA.. Or Miami...

Or as my grandmother might say, cut your cloth to fit the person. Don't cut the person to fit the cloth.

Hot_water_fan

Thus, for instance, a solution to a heating and air conditioning problem in, for instance, eastern Maryland, where an inch of snow can induce total panic, may not be the best solution for inland New England, where two feet of snow and 15 below might induce a half hour delay in starting school...and niether one would be of much value in guiding an intelligent policy or individual choice in, say San Diego, CA.. Or Miami...

Or as my grandmother might say, cut your cloth to fit the person. Don't cut the person to fit the cloth.

We hear you @Jamie Hall . No one is suggesting a one-size approach, but we appreciate the many reminders. That said, most clothes aren't tailor made and some approaches work for many people, while others are unpopular niches. Adding a heat pump to a ducted system (not forced water, not steam) when an AC is up for replacement is an easy, cheap choice for many people. It doesn't have to be a culture war, it can just be good advice.

Hot_water_fan

As to load reduction achieved by keeping reliable fossil fuel back up available in most buildings in say climate zone 4 and up, if not 3 and up, there is yin yang where the back up fuel is natural gas because of the pipeline constraints in some areas. So natural gas backup doesn't ease the transmission limits even if it lowers electric demand, albeit natural gas turbine generators have interrupts in constrained areas and must use LNG or oil backup for these times if they are contracted to generate. And, of course, all of us with LP and #2 systems ought to be onto those backup systems for high load events which also tend to be cold nights with the least renewable power available and when heat pumps would be operating at the lowest COP anyway. In this sense I don't think a focus on seasonal COP is so sensible.

I agree - peak times demand better solutions than currently offered and this problem is 100% foreseeable. The utilities should lead here, but if they don't, we can offer solutions. I love the propane/oil backup idea - as gas pipes move less gas, avoiding their cost would seem to be economical. Batteries fit this well too - as do thermal storage, increased insulation, load shifting, etc. Better pricing could spur some changes, but unclear of the magnitude.

I also believe that the installed base of heating in the Northeast recommends that heat pumps be operated in hybrid circumstances in most cases with better controls that can track the effective COP and fuel costs and call backup when the consumer is benefitted rather than some NGO anti-carbon religion that actually pays relatively little attention to actual carbon produced by the policies it advocates.

Can we please keep politics off the Wall? This name calling and insults help no one.

JakeCK

Jamie Hall said:

Or as my grandmother might say, cut your cloth to fit the person. Don't cut the person to fit the cloth.

Most Americans would benefit if they cut some fat... 

yesimon

@archibald tuttle A lot of bashing on ISO New England but it is actually making sensible moves given its constraints. Here are the limiting factors:

Electric grid capacity: Winter peak is still 20-30% lower than summer peak so there's still plenty room to add heat pumps

Winter natural gas: Voters will not allow new gas pipeline development in New England. This is not something ISO New England can control. (It's not even a good idea anymore since the US is now supplying 50% of Europe's natural gas imports). Thus New England rely on LNG (routed through Europe due to the Jones Act) and oil for cold winter days, especially for electricity generation. Oil is much dirtier than natural gas and combined with a 2 COP heat pump - that is worse for the environment than an 80% gas appliance! At first glance heat pumps look like a bad idea, but that's not understanding the limiting factor.

New England gas utilities secure contracts for pipeline natural gas first because they are the biggest customer, while power plants bid on the spot market for whatever is leftover. Since pipeline capacity into New England is already maxed out, power plants resort to buying more expensive LNG and oil (and this is reflected in the price of electric). If sufficient gas customers switch to heat pumps, then reduced overall demand for natural gas for heating will help switch off LNG/oil and better utilize the limited pipeline capacity available. That is a win on net costs and carbon emissions.

yesimon

Regarding renewable energy - it seems to be lost on many participants here that renewable energy has a very different financial profile compared to fossil fuels. Renewables cost much more $$$ upfront to build but a much lower operating cost over their operational life of decades (20+ years). That means lots and lots of financial pain in the beginning during buildout and expansion, but reaping financial rewards 10+ years in the future. Right now we're in the "financial pain" phase since new renewable generation is being massively built out off a very small installed base.

Seems a bit ironic also seeing complaints in this thread about Americans buying the cheapest kitchen and HVAC appliances that only last 10 years and unwilling to spend slightly more to get a much higher quality product. Holding off on instant gratification and investing in the future is a good thing!

archibald tuttle

@yesimon I don't take issue with ISO new england except some of their winter readiness policies.

most of my complaints are regarding state level policies and the NGOs (and utilities) that gerrymander those policies toward their interest. I agree that ISO doesn't block pipelines. This is classic public choice theory problem that the legislature and the regulators are captured by those with the most interest and the amount of attention that any one ratepayer would give to these matters is not justified by the impact they could have on the outcomes so they are just stuck with the self-interested machinations of all the aforementioned parties.

@Hot_water_fan I can only describe these policies as stupid and essentially religious and not even well tuned to the outcomes they seek. if that is name calling sobeit. I trust you can see that I really don't hover here for an opportunity to name call and even where it I do it is more in the 'if the shoe fits wear it vein' than targetting individuals.

but when the self same people advocate policies and then advocate for rate relief from the very rates they have caused, what do you call that? Stupid maybe is short for: totally insular to likely consequences of one's own advocacy.

and likewise, the way these policies make costs for the ratepayers is carefully hidden leading to your request to me for evidence and perhaps that frustration is manifest in my response.

I don't agree that there is actually extreme peaking electric capacity supporting large move to electric heating in the NE without fossil backup since winter peaks already force generators to release LNG or to go on oil backup or to not generate in which case we don't have that capacity that could otherwise be claimed. And that is why rates skyrocket. By all means, we have enough electricty for anyone willing to pay through the nose for it. How can one look at the rates quoted elsewhere and at our rates which are literally double (all in) and speak blithely about capacity. And since, to bring these two threads together, we have not had ISO winter readiness incentives in several years because they claim they aren't fuel independent. These people should get a life, or at least respect the lives of the ratepayers they are screwing.

but it isn't principally ISONE, it is state legislatures (and federal regs. what do you call bringing out a refrigerant that is obsolete before it even enters service?). is it name calling to call that stupid. I'm not saying I'm right. Argue that that these regs are smart or necessary if you think so. But these are the very politics of our industry. It is not our job to sit around until EPA says jump and we say how high. It is our job to head them off from doing stupid things or at least demonstrate that we tried and to foster discourse to let them know how wrongheaded their policies are.

That is not to debate their motives or the 'science' or whatever. this much more based on our emperical interaction with the installed based of HVAC. And my response is to a system that, insofar as I can see, is largely uninterested in the input of the folks who have to keep these systems running and regularly observe their experiental COP vs. the theoretical COP.

I can see that you and I have light bulb moments that cross, i.e. the importance of backup from stored fuels, not only for electric generation but fir residential heating. I am not hostile at all to economically and infrastructure defensible use of heat pumps although I'm not convinced that the subsidized pace of change is appropriate.

jumper

Here's another way to approach this question. Suppose you're off the grid.
Choice is propane generator powering a heat pump versus a propane heater.
Don't forget that you can utilize waste heat from generator to augment heating.
Clearly former will use less propane? But for OP the matter will come down to relative prices of electricity and fuel. From what I can tell electricity prices will increase more drastically than fuel.
In California delivery cost for NG is a dollar per therm. (energy is more than double)
In colder climates homeowners using more NG should be less per therm due to volume economies.
Electric distribution @ 25¢/kwhr ~ $7.50 per therm and it can only get worse.
So as long as we're still allowed to burn baby burn that is way to save $$$$.

Hot_water_fan

Here's another way to approach this question. Suppose you're off the grid.
Choice is propane generator powering a heat pump versus a propane heater.
Don't forget that you can utilize waste heat from generator to augment heating.
Clearly former will use less propane? But for OP the matter will come down to relative prices of electricity and fuel. From what I can tell electricity prices will increase more drastically than fuel.
In California delivery cost for NG is a dollar per therm. (energy is more than double)
In colder climates homeowners using more NG should be less per therm due to volume economies.
Electric distribution @ 25¢/kwhr ~ $7.50 per therm and it can only get worse.
So as long as we're still allowed to burn baby burn that is way to save $$$$.

I'm not sure I follow. If gas can be burnt in a combined cycle to power a heat pump or on-site, assuming the gas prices are similar/the same, the most efficient option wins if delivery prices are similar. That's currently the heat pump option for many places since combined cycle plants are the majority of gas generation. It uses less gas to get the same Btus. Is that what you're saying?

Jamie Hall

Might it not be useful in any study of space conditioning -- whether heating or air conditioning or indeed air quality -- to start off with a clear definition of the primary objective? Which is, I would argue, to maintain the space within a certain range of temperatures and with acceptable air quality? For a living space, such as a home, that might be at a very basic minimum between about 60 F and 85 F, for instance. One can tighten that range for comfort, of course, but going much outside that range has adverse health effects on most people.

Then one can examine the space in question, and determine how much heating or cooling power will be needed, under foreseeably extreme conditions, to maintain that temperature range (not "most of the time" -- all of the time).

Then one can examine the location of the space in question, and determine what power sources are available, and what machinery -- if any is required -- to provide that heating or cooling power, and evaluate them, and then choose the best available option. This analysis should involve a number of options, with a number of considerations -- not all of which will be obvious or perhaps even seemingly relevant on initial thought.

We all have a tendency -- it's perfectly natural -- to more or less automatically apply what we are familiar with and prefer, skipping right through to the end. Further, many of us, if we are honest, do not have enough experience with conditions outside of our usual area to be very good at this, reinforcing our tendency to apply what we know, whether it is the best solution -- or even a workable one. This is something to guard against!

Hot_water_fan

@Jamie Hall I think that's always been the goal and being respectful of people's time is important too.

jumper

Hot_water_fan said:

.

I'm not sure I follow. If gas can be burnt in a combined cycle to power a heat pump or on-site, assuming the gas prices are similar/the same, the most efficient option wins if delivery prices are similar. That's currently the heat pump option for many places since combined cycle plants are the majority of gas generation. It uses less gas to get the same Btus. Is that what you're saying?

Nope. My guess is that distribution cost of electricity is going to be much more than that for NG. So OP will be better off with gas heat no matter what energy usage is.

Hot_water_fan

Nope. My guess is that distribution cost of electricity is going to be much more than that for NG. So OP will be better off with gas heat no matter what energy usage is.

@jumper I am the OP. I am not better off with gas heat, it’s much more expensive. Our gas distribution cost is uneconomic and our electricity distribution cost is low. 

archibald tuttle

Hot_water_fan said:

If gas can be burnt in a combined cycle to power a heat pump or on-site, assuming the gas prices are similar/the same, the most efficient option wins if delivery prices are similar. That's currently the heat pump option for many places since combined cycle plants are the majority of gas generation. It uses less gas to get the same Btus. Is that what you're saying?

think your presumption of combined cycle is mistaken because you are looking across the electric load and supplementing renewables and peaking calls conventional gas turbines not combined cycle which takes longer to come online.

it is conceivable that more combined cycle might be called by plan anticipating demand, but stochastic decisions on the margin are not combined cycle and if you call too much combined cycle the efficiency drops without full capacity utilization.

if the extreme demand is cold then the COP of the heat pumps, even assuming combined cycle, does not necessarily suggest that is better approach. The best hyper heat pumps, ergo not most of them out there, can just crest 2 COP in the low single digits. That makes the distinction between gas turbine and combined cycle critical to this distinction as you at break even at best with 80% efficient home heating and gas turbine but still show a modest advantage with combined cycle. Meanwhile, the installed base is more like break even with combined cycle suggesting that we'd be better off and more resilient with gas heating during extreme consumption events.

I feel like you are trying to back into justification for heat pumps without fossil backup. This can work if residences are flexible on indoor temps during extreme events. I have friends who are willing to accept even the low end of @Jamie Hall 's supposition, when he mentions 60-85 target temps, during such events who are happy with heat pump only systems. This goes to @Jamie Hall point about taking the individual requirements and characteristics into consideration. (that would also include the insulation and sealing characteristics of the residence, perhaps the placement of outdoor units relative to compass, sun, wind with moisture, etc. Likewise, for me, that takes into account existing heating system!)

I certainly agree we have technology that could heat homes with heat pumps without backup, but I am saying that most homes already have heating and I would not abandon those systems but use them as tradeoffs given electric capacity questions even assuming relatively favorable seasonal COPs. In no small part this perception is also fueled by @Mad Dog_2 barking :-) regarding longevity/resilience (cost?) of equipment as a significant consideration. The hyper heat units are on the order of twice the cost of more standard decent but not extreme seer crossover AC to heat pumps. And refrigerant life for these units is pegged at 7 years for the average system by EPA. And service of almost any sort where refrigerant loss is suspected is by resort to complete evacuation (maybe the presumption that even with modest refrigerant loss refrigerant that is evacuated is not as regularly recharged is what leads to that 7 year figure or . . . ?). With those reliabilities or lack thereof, I'm less interested in general in recommending folks get out on the ledge of no backup, but that's me.

Maybe techs grasp of these units is going to improve those numbers, but I'll be watching for my own anecdotal evidence and for industry averages/norms in contemplating more favorable disposition toward these units. I like to think my practices would beat those industry numbers. But I don't have anything that has been in service for 7 years (like 4 years to go actually) before I know if I made it. Still wishing that the units generally had more and better taps for diagnosis and charging and maybe level indicators for the accumulator or built in indication for these metrics for that matter, i.e. better OBD. you can get faults out of many of them, but how about just multiple operating parameters without having to tap the system?


there is another 2¢ for ya.

brian

archibald tuttle

@yesimon one note on your thoughts on impediments to gas pipelines. I think voters would allow new gas pipelines, but they don't prioritize that since it is not the only issue on which they elect people.

Hot_water_fan

think your presumption of combined cycle is mistaken because you are looking across the electric load and supplementing renewables and peaking calls conventional gas turbines not combined cycle which takes longer to come online.

it is conceivable that more combined cycle might be called by plan anticipating demand, but stochastic decisions on the margin are not combined cycle and if you call too much combined cycle the efficiency drops without full capacity utilization.

Fair! Combined cycles are quick to build but CT are quicker. Initially, maybe the increased load outpaces the combined cycles, but I trust they'll catch up - they're the dominant gas generator, so it seems like the industry has figured it out. Time will tell!

if the extreme demand is cold then the COP of the heat pumps, even assuming combined cycle, does not necessarily suggest that is better approach. The best hyper heat pumps, ergo not most of them out there, can just crest 2 COP in the low single digits. That makes the distinction between gas turbine and combined cycle critical to this distinction as you at break even at best with 80% efficient home heating and gas turbine but still show a modest advantage with combined cycle. Meanwhile, the installed base is more like break even with combined cycle suggesting that we'd be better off and more resilient with gas heating during extreme consumption events.

Agree with you again - there will undoubtedly be hours where a heat pump is dirtier than burning gas on-site. My argument is that might be 1-5% of the year, hence the seasonal COP discussion.

I feel like you are trying to back into justification for heat pumps without fossil backup. This can work if residences are flexible on indoor temps during extreme events. I have friends who are willing to accept even the low end of @Jamie Hall 's supposition, when he mentions 60-85 target temps, during such events who are happy with heat pump only systems. This goes to @Jamie Hall point about taking the individual requirements and characteristics into consideration. (that would also include the insulation and sealing characteristics of the residence, perhaps the placement of outdoor units relative to compass, sun, wind with moisture, etc. Likewise, for me, that takes into account existing heating system!)

I would never be happy with low 60s indoors. I think that's so obvious a requirement that it's a waste of time to discuss with every post. I don't think that disqualifies heat pumps, just poorly sized ones with poor low ambient capacity. It also disqualifies poorly sized boilers and furnaces. I agree, if a heat pump can't meet a set point it should be backed up if a customer values that (which I assume most do). I push back on the assertion that every heat pump can't keep a house comfortable - I have personal experience to the contrary.

I certainly agree we have technology that could heat homes with heat pumps without backup, but I am saying that most homes already have heating and I would not abandon those systems but use them as tradeoffs given electric capacity questions even assuming relatively favorable seasonal COPs. In no small part this perception is also fueled by @Mad Dog_2 barking :-) regarding longevity/resilience (cost?) of equipment as a significant consideration. The hyper heat units are on the order of twice the cost of more standard decent but not extreme seer crossover AC to heat pumps. And refrigerant life for these units is pegged at 7 years for the average system by EPA. And service of almost any sort where refrigerant loss is suspected is by resort to complete evacuation (maybe the presumption that even with modest refrigerant loss refrigerant that is evacuated is not as regularly recharged is what leads to that 7 year figure or . . . ?). With those reliabilities or lack thereof, I'm less interested in general in recommending folks get out on the ledge of no backup, but that's me.

I will never disagree about hybrids - they're a great compromise and let you use the lower end heat pumps. My point has always been that when an AC reaches end of life, a heat pump can cheaply replace it and allow a customer access to many more heating energy sources via electricity. To some, keeping the fossil makes sense even if it's used sparingly. To others, it'll be replaced, like in my situation. The hyper heat unit was nowhere close to 2x the cost of the low end heat pump in my experience, but everyone's situation will be different. I agree reliability matters, I reject that it plays much into people's decisions beyond a typical AC lifetime, say 15-20 years. People just value money today too much to risk much beyond that - and we see evidence of this in so many consumer products.