COP is used because it's a lot easier to understand than BTU/kWh. Everyone agrees there may be a point where gas heating emits less carbon than using gas fired electricity to power a cold climate heat pump, but those circumstances are very rare and over the course of a year the heat pump will have vastly lower emissions, and will only have lower emissions over time as the grid gets greener.
I agree grid reliability isn't amazing in Lincoln with overhead power lines and lots of trees. But a battery and/or a generator is a great emergency backup. -Nick On Mon, Dec 29, 2025, 19:51 Arthur Buckland <[email protected]> wrote: > > Thank you, what a huge benefit to all of us to have Lincoln's CREE group- > a wonderful resource for us non-technical older folks > > Yes, it is true Mitsubishi’s new inverter-driven compressors (cold > temperature HVACs) are an engineering marvel. Their low temperature models > even perform much better at high temps than conventional HVACs, and even > many stand alone AC units. Mitsubishi does though obfuscate their > efficiency numbers by using this vague COP metric and then give a > multiplier in their engineering manuals in a different section, and never > ever give the normal efficiency curves for this type of equipment. And it > appears they are intentionally trying to hide the kWh (kilowatt hours- this > is half of the charges on your Eversource bill the other half is a > "delivery charge") to BTU (British thermal Units or "therms") efficiencies > > Mainly, I am most concerned about the unreliable and inefficient Lincoln > electricity distribution system. If there is a power outage in a storm no > matter how efficient the HVAC is, there is no heat produced. In this last > storm one of the Hive stated they had no electricity for 28 hours and it > was not even a big storm. The advantages of gas-fired home furnaces are > they are generally not subject to distribution disruption and have a 98% > conversion from natural gas to BTUs. That compares with modern gas-fired > CCGT electricity power plants which run at best a 62% gas to kWh conversion > rate and then send the electricity down our Lincoln grid which has at best > an 8% transmission loss. That means our electricity uses ~2X more gas, > generating twice the carbon, before any HVAC begins to convert the > electricity to heat > For the Mitsubishi model MUZ-FH12NAH-1 (one of the best cold temp HVACs) I > asked Chat GPT to convert the Mitsubishi published COP numbers to BTU heat > delivered per 1kWh: > *Outdoor ambient temp (degrees f,)* * BTU heat /1 kWh* > > 47 15,354 (normal above this) > 17 8,456 > 5 7,376 > -13 6,824 > So I think you can see once you get below 15 degrees Fahrenheit you > consume twice the electricity to heat your home ( with 4X the carbon > produced) , but the good news is, if you have one of these systems, they > continue to heat down to pretty low temperatures as long as there is > electricity. > > I should be clear; we have this model of cold temp Mitsubishi mini split > installed in our home. It is for an auxiliary room without plumbing and we > will be installing US-made 24% efficiency solar panels with batteries > (unfortunately using Chinese precious metals) to power it and charge our > Mitsubishi (coincidentally) hybrid car > > I am, I guess, particularly sensitive to this matter, because we moved > here from Concord, MA where the electricity costs about a third of what it > does here in Lincoln and we had one power outage in 16 years that lasted 4 > hours. We have already had 2 outages in a year from a mild storm and a car > crash. The old power lines here are badly maintained with trees and bushes > hanging all over the lines, but it gives Eversource a license to charge > huge delivery bills > > > With warm regards, > Art > +1 978.873.3000 > > > > On Dec 29, 2025, at 11:05 AM, Stephen Dirrane <[email protected]> > wrote: > > Hello All- > > Chuck Sizer, a founding member of Lincoln’s CFREE (carbon free > residential- everything electric) group and a refrigeration engineer, > monitored the coefficiency of performance (CoP) on his Mitsubishi heat pump > a few years back when the temperature dropped to subzero temperatures. > > Having been at his house and looked at all of the graphs with watt > consumption tied in, I was amazed to see that, as Nick suggests, the CoP > was able to shadow the temperatures exactly- meaning there was no increase > of cost to provide temperature per degree with a heat pump; so the > efficiency and economy maintained all the way to -5°. Hvac engineer savant > Antis Hartmann echoed Nick’s statement about newer systems having a steady > CoP all the way down to -15°. > > Lincoln is fortunate to have perhaps the most advanced committee reviewing > apparatus, legislation and other initiatives towards more environmentally, > sustainable and efficient energy with the CFREE group. Their meetings are > advertise through Town’s website and a lot of their information has been > posted to YouTube. For any resident consider considering upgrading their > heating system, adding solar panels, and/or battery backups, or even > considering an EV versus another combustion engine purchase, please reach > out and take advantage of this amazing group of community- minded, locally > active (slightly nerdy) individuals who have amassed tremendous amounts of > information and insight. > > Stephen Dirrane > > > Sent from my iPhone > > On Dec 28, 2025, at 8:43 PM, Nick Gardner <[email protected]> wrote: > > > That is unfortunately outdated information. With modern cold climate heat > pumps, the heat pumps are more environmentally friendly than natural gas > heating at around 15f if you're on the Lincoln basic plan and have a 95% > efficient furnace. If you are on the standard plan, it's *always* more > environmentally friendly to run the heat pumps instead of gas. The > technology has greatly improved recently. Happy to go over the numbers with > anyone if they'd like, I'm a bit proponent of heat pumps. > > I do agree about power reliability, but battery backup solutions have > gotten a lot better recently as well. > > -Nick > > On Sun, Dec 28, 2025, 20:09 Arthur Buckland <[email protected]> wrote: > >> Thank you, Nick, >> >> You are correct that point 1 about the unreliable Lincoln electric grid >> is the most important >> >> But you might check your HVAC system: >> >> “Areas of the country subjected to temperatures 40 degrees and lower for >> extended periods are not ideal for a heat pump installation. >> >> Why? Well, as the temperature drops, heat pumps work harder to maintain >> desired comfort levels. This results in more energy use, driving up your >> utility bill. >> >> In addition, once the temperature drops below 40 degrees, most heat pump >> systems lose their heating efficiency and must switch to emergency heat >> mode, which utilizes electric resistant heat strips that use more >> electricity.” >> >> And you are correct, below 0 f. the heat strips are almost useless except >> to generate huge electric bills. It is like heating your home with >> non-oil-filled electric space heaters >> >> Also since Massachusetts generally has very efficient gas-fired/generated >> electricity on our grid, the extra electricity to generate heat from HVACs >> consumes vastly more green house gases than direct conversion from gas at >> our homes >> >> Heating with electricity below 32f is bad for the environment. >> With warm regards, wishing all a peaceful and healthy 2026 >> Art >> +1 978.873.3000 >> >> On Dec 28, 2025, at 6:26 PM, Nick Gardner <[email protected]> wrote: >> >> >> I'd push back against number 2 in particular. Cold climate heat pumps >> typically provide full output down to 5f and still operate at -13f. I and >> many others use heat pumps as a primary method of HVAC and have had no >> issue even on the coldest of cold days. >> >> -Nick >> >> On Sun, Dec 28, 2025, 18:17 Arthur Buckland via Lincoln < >> [email protected]> wrote: >> >>> Rosemary >>> >>> Erik Lyons - (978) 621-2642 >>> New business, hard working, local >>> >>> Max heating & cooling >>> Sam or Dan >>> (617) 453-8865 >>> Best in Boston >>> >>> Do not use HVAC for heating in Lincoln >>> 1. Lincoln’s electric grid is too unreliable (I think Eversource >>> cultivates tree growth over our old fragile power lines) >>> 2. HVACs are not designed for very cold weather which we occasionally >>> have >>> >>> If you insist on HVACs have a good wood- burning stove in the house >>> >>> With warm regards, >>> Art >>> +1 978.873.3000 >>> >>> On Dec 28, 2025, at 10:12 AM, Deb Wallace <[email protected]> >>> wrote: >>> >>> >>> Rosemary, >>> >>> Have you tried Haffner's formerly Concord Oil? They have been servicing >>> my furnace for decades and I have been very satisfied with them. >>> https://www.haffners.com/ >>> >>> Deb >>> >>> >>> On Sun, Dec 28, 2025 at 8:43 AM Rosemary Lloyd <[email protected]> >>> wrote: >>> >>>> Hello Hive, >>>> We need to replace two gas fired furnaces (sadly, two reputable >>>> companies have concluded we cannot replace with heat pumps). Looking for >>>> recommendations for high efficiency furnace and a great company to procure >>>> and install them. Thanks! >>>> >>>> Rosemary >>>> -- >>>> The LincolnTalk mailing list. >>>> To post, send mail to [email protected]. >>>> Browse the archives at >>>> https://pairlist9.pair.net/mailman/private/lincoln/. >>>> Change your subscription settings at >>>> https://pairlist9.pair.net/mailman/listinfo/lincoln. >>>> >>>> -- >>> The LincolnTalk mailing list. >>> To post, send mail to [email protected]. >>> Browse the archives at >>> https://pairlist9.pair.net/mailman/private/lincoln/. >>> Change your subscription settings at >>> https://pairlist9.pair.net/mailman/listinfo/lincoln. >>> >>> -- >>> The LincolnTalk mailing list. >>> To post, send mail to [email protected]. >>> Browse the archives at >>> https://pairlist9.pair.net/mailman/private/lincoln/. >>> Change your subscription settings at >>> https://pairlist9.pair.net/mailman/listinfo/lincoln. >>> >>> -- > The LincolnTalk mailing list. > To post, send mail to [email protected]. > Browse the archives at https://pairlist9.pair.net/mailman/private/lincoln/ > . > Change your subscription settings at > https://pairlist9.pair.net/mailman/listinfo/lincoln. > > -- > The LincolnTalk mailing list. > To post, send mail to [email protected]. > Browse the archives at https://pairlist9.pair.net/mailman/private/lincoln/ > . > Change your subscription settings at > https://pairlist9.pair.net/mailman/listinfo/lincoln. > >
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