Every factual sentence carries assertions checked against the recorded evidence: references must resolve, figures and quotations must be in the cited passage, arithmetic must reproduce, and an independent reviewer must approve the wording. Automated validation says whether the narration is ready for human editorial review; it does not establish truth.
Open a sentence to see its assertions, their status and the passages behind them. Sentences without a marker make no factual claim.
verified s04.a Atlas AC said heat pumps are more energy efficient than gas systems and should save $300 to $500 in energy cost each year.
supported (approved): no direct support, 5 contradicting, 3 qualifying, 1 source statement.
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s05.a Jonathan Tracey said of being told a heat pump will save money: "the reality is for most people, that is not true".
supported (approved): no direct support, 3 qualifying, 1 source statement.
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s06.a Guy Martin said electricity is 4 times the price of gas, so the heat pump's efficiency and the price meet in the middle.
supported (approved): no direct support, 3 qualifying, 1 source statement.
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s09.a A heat pump heats more cheaply than a gas furnace when its seasonal average COP is above the electricity-to-gas price ratio, on an energy-content basis, times the furnace's AFUE.
qualified (qualify): no direct support, 3 qualifying.
warning needs-qualification: EIA, state residential electricity and gas prices: The break-even seasonal COP is the electricity-to-gas price ratio times the furnace AFUE (US 2024: 3.45 x 0.95 = 3.28), so the threshold is slightly below the raw price ratio. Add the qualification: the evidence supports a narrower or weaker statement.
verified s10.a At 2024 US average prices the electricity-to-gas price ratio was 3.45, so the break-even seasonal COP against a furnace with AFUE 0.95 was 3.28.
qualified (qualify): no direct support, 3 qualifying.
warning needs-qualification: EIA, state residential electricity and gas prices: The break-even seasonal COP is the electricity-to-gas price ratio times the furnace AFUE (US 2024: 3.45 x 0.95 = 3.28), so the threshold is slightly below the raw price ratio. Add the qualification: the evidence supports a narrower or weaker statement.
verified s11.a At 2024 average prices a heat pump with seasonal COP 2.5 beats a 95% furnace on running cost in 11 states, including Florida and Texas, while 30 places, including California and New York, need a seasonal COP of 3.0 or higher.
qualified (qualify): no direct support, 6 qualifying.
warning needs-qualification: EIA, state residential electricity and gas prices: At 2024 average prices a seasonal COP of 2.5 beats a 95% furnace in only 11 states; 30 states need COP 3 or more, so it depends on location and efficiency. EIA, state residential electricity and gas prices: The break-even seasonal COP is the electricity-to-gas price ratio times the furnace AFUE (US 2024: 3.45 x 0.95 = 3.28), so the threshold is sl…
verified s12.a The break-even rule uses average prices and ignores tiered or time-of-use rates and backup resistance heat; average gas prices include fixed customer charges, which a household that keeps its gas connection keeps paying and one that disconnects saves.
qualified (qualify): no direct support, 3 qualifying.
warning needs-qualification: EIA, state residential electricity and gas prices: The break-even seasonal COP is the electricity-to-gas price ratio times the furnace AFUE (US 2024: 3.45 x 0.95 = 3.28), so the threshold is slightly below the raw price ratio. Add the qualification: the evidence supports a narrower or weaker statement.
verified s14.a In the NREL and LBNL study, for homes heating with natural gas and with AC, the share with positive bill savings ranged from 38% to 99% depending on ASHP performance level.
qualified (qualify): no direct support, 8 qualifying, 1 context only.
warning needs-qualification: Wilson 2024 (NREL and LBNL), heat pumps for all?: For gas-heated homes with AC, the share with lower bills ranges from 38% (minimum-efficiency, median -$70/yr) to 99% (cold-climate high-efficiency, median $380/yr), and only 5-58% for gas homes without AC; it holds only for efficient equipment. Wilson 2024 (NREL and LBNL), heat pumps for all?: With minimum-efficiency equipment most gas homes with A…
verified s14.b The NREL and LBNL main case used winter 2021-2022 fuel prices.
qualified (qualify): 1 supporting (1 independent, strongest 0.55), 3 qualifying.
warning needs-qualification: RMI 2018, the economics of electrifying buildings: In RMI's gas retrofits, heat pumps either raise energy costs (Chicago, Providence) or save too little to recover the extra capital (Houston, Oakland), so for most gas homes they never pay back at 2018 prices. [partial: gas retrofits in four modelled cities either cost more to run or save too little to recover the capital; four cities and 2018 pric…
verified s15.a For homes heating with natural gas but without AC, only 5% to 58% had positive bill savings, lower than the 38% to 99% for gas homes with AC.
qualified (qualify): no direct support, 8 qualifying, 1 context only.
warning needs-qualification: Wilson 2024 (NREL and LBNL), heat pumps for all?: For gas-heated homes with AC, the share with lower bills ranges from 38% (minimum-efficiency, median -$70/yr) to 99% (cold-climate high-efficiency, median $380/yr), and only 5-58% for gas homes without AC; it holds only for efficient equipment. Wilson 2024 (NREL and LBNL), heat pumps for all?: With minimum-efficiency equipment most gas homes with A…
verified s15.b Homes without existing AC are more likely to see energy bill increases because of the new central AC the heat pump provides.
qualified (qualify): 1 supporting (1 independent, strongest 0.5), 1 qualifying.
warning needs-qualification: Canadian Climate Institute 2023, heat pumps pay off: Doubling as cooling is one reason heat pumps beat gas plus AC on lifetime cost, but the model always compares full replacements and does not test the case where only the furnace is due. Add the qualification: the evidence supports a narrower or weaker statement.
verified s16.a A return to 2019 energy prices would reduce the percentage of natural-gas homes with positive bill savings, in the NREL and LBNL study.
qualified (qualify): no direct support, 3 qualifying.
warning needs-qualification: Wilson 2024 (NREL and LBNL), heat pumps for all?: Bill savings are very sensitive to prices (2019 elec-to-gas ratio 4.1 cuts gas homes with positive savings from 32-92% to 22-83%), but the range itself shows equipment efficiency matters as much as prices, so 'mainly prices' overstates. Add the qualification: the evidence supports a narrower or weaker statement.
verified s18.a In the UK study, total energy use fell 40% in homes heated by heat pumps compared with gas-boiler homes, but because electricity costs more per kWh than gas, running costs were estimated slightly higher.
qualified (qualify): 1 supporting (1 independent, strongest 0.45), 3 qualifying.
warning needs-qualification: Edwards 2024, inequities in heat pump bill savings: Edwards finds large regional differences in heat pump operating costs that depend on local climate as well as the price of electricity relative to gas, so prices are a main driver but not the only one. Wilson 2024 (NREL and LBNL), heat pumps for all?: Bill savings are very sensitive to prices (2019 elec-to-gas ratio 4.1 cuts gas homes with positi…
verified s19.a Heat pumps cost £190 more per year to run than gas boilers, based on Octopus Energy's standard tariff electricity and gas prices as of 15 June 2024 in the UK.
qualified (qualify): 1 supporting (1 independent, strongest 0.55), 3 qualifying.
warning needs-qualification: Wilson 2024 (NREL and LBNL), heat pumps for all?: For gas-heated homes with AC, the share with lower bills ranges from 38% (minimum-efficiency, median -$70/yr) to 99% (cold-climate high-efficiency, median $380/yr), and only 5-58% for gas homes without AC; it holds only for efficient equipment. EIA, state residential electricity and gas prices: At 2024 average prices a seasonal COP of 2.5 beats a 9…
verified s19.b Customers pay approximately £100 per year for their mains gas connection, and disconnecting from mains gas further reduces annual costs by £100.
qualified (qualify): no direct support, 5 qualifying, 1 context only.
warning needs-qualification: Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff: UK households switching from gas boilers see running costs about £190/yr higher on a standard tariff (about £83 after dropping the gas standing charge), so bills do rise modestly; but the same paper finds a heat pump time-of-use tariff saves about £318/yr, enough to reverse the rise. Add the qualification: the evidence supports a narrowe…
warning needs-human (review): The Cosy result (and the £4,675 in s35 that more than covers the heat pump's net cost) comes from authors whose Centre for Net Zero is part of Octopus Energy Group (Bernard front matter, conflicts of interest), in an NBER working paper not peer reviewed. The narration now names Cosy as Octopus's own tariff and drops the £318, but never says who did the study; the writer notes the affiliation decides no claim and so cannot be cited. Only an editor can decide whether to record it or accept the sentence as is.
verified s21.a Switching to the Cosy time-of-use tariff saved customers £318 per year compared with Octopus Energy's standard tariff, of which £240 came from changing consumption by period of the day.
qualified (qualify): 1 supporting (1 independent, strongest 0.7), 2 qualifying.
warning needs-qualification: RMI 2018, the economics of electrifying buildings: In RMI's models a tariff alone does not cut costs: a standard heat pump on Houston's Free Nights rate costs more than on a flat rate, and only flexible control on steep tariffs (3:1 TOU, Free Nights) saved about $1,000-2,000 over 15 years, while mild default TOU gave too little. Wilson 2024 (NREL and LBNL), heat pumps for all?: Where time-of-use r…
verified s22.a In RMI's Houston model, heat pumps on TXU Energy's Free Nights rate have higher costs than on a flat rate, and for a customer on that rate, optimizing the heat pump to preheat or precool while electricity is free saves around $1,000 in net present cost.
qualified (qualify): no direct support, 2 qualifying.
warning needs-qualification: RMI 2018, the economics of electrifying buildings: In RMI's models a tariff alone does not cut costs: a standard heat pump on Houston's Free Nights rate costs more than on a flat rate, and only flexible control on steep tariffs (3:1 TOU, Free Nights) saved about $1,000-2,000 over 15 years, while mild default TOU gave too little. Add the qualification: the evidence supports a narrower or weaker sta…
verified s23.a For gas-heated homes with AC, the share with positive bill savings rises to 99% at the highest ASHP performance level but is 38% at the lowest.
qualified (qualify): 1 supporting (1 independent, strongest 0.55), 8 qualifying, 1 context only.
warning needs-qualification: Wilson 2024 (NREL and LBNL), heat pumps for all?: For gas-heated homes with AC, the share with lower bills ranges from 38% (minimum-efficiency, median -$70/yr) to 99% (cold-climate high-efficiency, median $380/yr), and only 5-58% for gas homes without AC; it holds only for efficient equipment. Wilson 2024 (NREL and LBNL), heat pumps for all?: With minimum-efficiency equipment most gas homes with A…
verified s23.b The break-even seasonal COP equals the electricity-to-gas price ratio times the furnace's AFUE, so a higher price ratio needs a more efficient heat pump.
qualified (qualify): no direct support, 3 qualifying.
warning needs-qualification: EIA, state residential electricity and gas prices: The break-even seasonal COP is the electricity-to-gas price ratio times the furnace AFUE (US 2024: 3.45 x 0.95 = 3.28), so the threshold is slightly below the raw price ratio. Add the qualification: the evidence supports a narrower or weaker statement.
warning missing-qualification (review): 'Still paid more' is the standard-tariff result (Bernard L1850-L1855); s21 has just told the viewer that Cosy customers saved against that tariff, and the paper's £318 Cosy saving exceeds the £190 gap, so the unqualified line reads as if every British home paid more. The halving rebuttal itself holds either way.
verified s25.b In the UK study, homes that switched from gas boilers cut total energy use yet had somewhat higher running costs than gas boilers.
qualified (qualify): 1 supporting (1 independent, strongest 0.45), 5 qualifying.
warning needs-qualification: Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff: In the UK, replacing a gas boiler with a heat pump raised measured running costs by about £190/yr on a standard tariff, far from halving bills, even though energy use fell 40%. Add the qualification: the evidence supports a narrower or weaker statement.
verified s27.a Atlas AC said the increased cost to convert a gas system to a heat pump could be offset in savings by year 5.
supported (approved): no direct support, 1 contradicting, 2 qualifying, 4 context only, 1 source statement.
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s30.a Deetjen counts only the extra cost of a heat pump over replacing the existing heater with a similar technology, assuming purchase when the existing heater nears the end of its life; Wilson's reference scenario is like-for-like replacement of equipment at end of lifetime.
supported (qualify): 2 supporting (2 independent, strongest 0.4).
warning needs-qualification: The strongest support is weak (0.4); say "one study suggests" or find stronger evidence.
verified s31.a Lower-cost minimum-efficiency ASHPs have the largest share of households with positive unsubsidized NPV (55%); the higher upfront costs of the medium and high-efficiency cold-climate scenarios reduce the share to 41% and 21%.
qualified (qualify): 2 supporting (1 independent, strongest 0.6), 8 qualifying.
warning needs-qualification: RMI 2018, the economics of electrifying buildings: In RMI's gas retrofits, heat pumps either raise energy costs (Chicago, Providence) or save too little to recover the extra capital (Houston, Oakland), so for most gas homes they never pay back at 2018 prices. [partial: gas retrofits in four modelled cities either cost more to run or save too little to recover the capital; four cities and 2018 pric…
verified s32.a The group with positive unsubsidized NPV from minimum-efficiency ASHPs includes most homes that use fuel oil, propane, or electricity for heating, and also most homes that use natural gas and have central AC in warmer climates.
qualified (qualify): 1 supporting (1 independent, strongest 0.55), 3 qualifying.
warning needs-qualification: RMI 2018, the economics of electrifying buildings: In RMI's gas retrofits, heat pumps either raise energy costs (Chicago, Providence) or save too little to recover the extra capital (Houston, Oakland), so for most gas homes they never pay back at 2018 prices. [partial: gas retrofits in four modelled cities either cost more to run or save too little to recover the capital; four cities and 2018 pric…
verified s33.a Deetjen finds 21% of the US single-family residential stock could benefit economically from replacing their existing heater with a heat pump.
qualified (qualify): 1 supporting (1 independent, strongest 0.5), 3 qualifying, 1 context only.
warning needs-qualification: RMI 2018, the economics of electrifying buildings: In RMI's gas retrofits, heat pumps either raise energy costs (Chicago, Providence) or save too little to recover the extra capital (Houston, Oakland), so for most gas homes they never pay back at 2018 prices. [partial: gas retrofits in four modelled cities either cost more to run or save too little to recover the capital; four cities and 2018 pric…
verified s33.b Switching a home's heating fuel from natural gas to a heat pump rarely produces a benefit, especially in cold climates where there are almost no houses where the switch makes sense, with the heat pump costed against replacing the old heater at the end of its life.
supported (approved): 2 supporting (1 independent, strongest 0.5).
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s34.a In the UK study, the net private cost of the heat pump over 20 years is £4,121, even after the grant: the £5,213 private capital expenditure minus the £2,250 avoided expenditure on a gas boiler plus £1,159 higher net present operating cost.
supported (qualify): 2 supporting (1 independent, strongest 0.4).
warning needs-qualification: The strongest support is weak (0.4); say "one study suggests" or find stronger evidence.
verified s35.a Assuming the Cosy savings persist across 20 years, their net present value is £4,675, and the net private cost of the heat pump is lower than that.
qualified (qualify): 1 supporting (1 independent, strongest 0.7), 7 qualifying.
warning needs-qualification: Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff: In the UK the heat pump's net private cost after the grant is about £4,121 over 20 years on a standard tariff (it does not pay off), but switching to the heat pump time-of-use tariff is worth about £4,675, which more than covers it. Add the qualification: the evidence supports a narrower or weaker statement.
verified s37.a In the Minnesota study, the average ccASHP with propane furnace back-up costs $9,450 installed; with no failure the incremental cost is the full $9,450 and the simple payback is 14.5 years against an 82% furnace and 28.8 years against a condensing furnace.
supported (approved): 1 supporting (1 independent, strongest 0.55).
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s38.a At A/C failure the simple payback falls to 13.0 and 6.5 years from 28.8 and 14.5; when both furnace and A/C need replacement the incremental cost is $370 and the simple payback 1.1 and 0.6 years, less than one year in the report's words.
qualified (qualify): 1 supporting (1 independent, strongest 0.5), 1 qualifying.
warning needs-qualification: Canadian Climate Institute 2023, heat pumps pay off: Doubling as cooling is one reason heat pumps beat gas plus AC on lifetime cost, but the model always compares full replacements and does not test the case where only the furnace is due. Add the qualification: the evidence supports a narrower or weaker statement.
verified s39.a The Minnesota payback figures are for a ccASHP with propane furnace back-up, not natural gas.
supported (approved): 1 supporting (1 independent, strongest 0.55).
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s40.a In many retrofit scenarios for a home with existing natural gas heating, switching to heat pumps is more expensive than retrofitting with new gas equipment; a notable exception is the customer needing to replace both furnace and air conditioner, which a single heat pump replaces.
qualified (qualify): 1 supporting (1 independent, strongest 0.5), 1 qualifying.
warning needs-qualification: Canadian Climate Institute 2023, heat pumps pay off: Doubling as cooling is one reason heat pumps beat gas plus AC on lifetime cost, but the model always compares full replacements and does not test the case where only the furnace is due. Add the qualification: the evidence supports a narrower or weaker statement.
verified s41.a In LBNL's archetypal projects for homes without cooling, electric upgrades cost more than gas ones by almost exactly the cost of adding cooling, implying no cost premium when comparing like-for-like upgrades that add both heating and cooling.
qualified (qualify): 1 supporting (1 independent, strongest 0.35), 1 qualifying.
warning needs-qualification: Canadian Climate Institute 2023, heat pumps pay off: Doubling as cooling is one reason heat pumps beat gas plus AC on lifetime cost, but the model always compares full replacements and does not test the case where only the furnace is due. Add the qualification: the evidence supports a narrower or weaker statement.
verified s42.a Switching from natural gas to a heat pump rarely produces a private benefit even at end-of-life replacement, and for gas homes only needing a new furnace it is usually more expensive to electrify than to stay with gas.
supported (approved): 2 supporting (2 independent, strongest 0.5).
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
verified s42.b When both furnace and air conditioner need replacing, the heat pump's incremental cost falls to $370 in Minnesota and RMI names this the exception for gas homes; LBNL finds no cost premium once cooling is added as well; at air conditioner failure alone the incremental cost falls only to $4,270.
qualified (qualify): 3 supporting (3 independent, strongest 0.5), 1 qualifying.
warning needs-qualification: Canadian Climate Institute 2023, heat pumps pay off: Doubling as cooling is one reason heat pumps beat gas plus AC on lifetime cost, but the model always compares full replacements and does not test the case where only the furnace is due. Add the qualification: the evidence supports a narrower or weaker statement.
verified s43.a Bill savings vary geographically with climate, energy prices and housing stock, and there is even more variation between the 5th and 95th percentiles within a given location.
supported (approved): 1 supporting (1 independent, strongest 0.7).
info wording: Wording differs from the canonical claim; the reviewer confirms the passages entail it.
34 scenes, 9:26 at 150 words per minute including pauses. Narration is copied from the script; every chart value and on-screen citation is checked against a passage.
1. sc01 · 0:00 to 0:11 typography
Picture neighbours on the same street who put in heat pumps the same autumn: by February, one has a smaller heating bill and the other a bigger one.
Visual. Split field: "Smaller bill" lands on the left in green on "smaller heating bill"; "Bigger bill" lands on the right in red on "bigger one".
On screen. Smaller bill / Bigger bill
2. sc02 · 0:11 to 0:22 typography
Neither of them is lying. So is a heat pump actually cheaper to run than a gas furnace, and does it ever pay for itself?
Visual. The question types on, large and centred; "cheaper" and "pay for itself" take the two colours from the previous scene.
On screen. Cheaper than gas, and does it pay for itself?
3. sc03 · 0:22 to 0:37 typography
The channel Atlas AC makes one case: heat pumps "are more energy efficient than gas systems and should be able to save you $300 to $500 in energy cost each year".
Visual. Quote card, text only; "$300 to $500" turns green as it is spoken.
On screen. "should be able to save you $300 to $500 in energy cost each year"
Cite. Atlas AC, YouTube
4. sc04 · 0:37 to 0:51 typography
Jonathan Tracey, comparing his own heat pump's costs with gas, says the opposite: "when you're told that having a heat pump will save you money, the reality is for most people, that is not true".
Visual. Quote card, text only, mirrored from the previous one; "not true" turns red as it is spoken.
On screen. "for most people, that is not true"
Cite. Jonathan Tracey, YouTube
5. sc05 · 0:51 to 1:04 typography
Guy Martin, testing a heat pump on his channel, put the catch in one line: "Trouble is, electric's four times the price of gas, so it's all meeting the middle."
Visual. Quote card, text only; "four times the price of gas" holds and turns amber.
On screen. "electric's four times the price of gas"
Cite. Guy Martin, YouTube
6. sc06 · 1:04 to 1:09 typography
So which wins: the efficiency, or the price? The arithmetic fits in one line.
Visual. The question types on centred; "efficiency" in green, "price" in red.
On screen. The efficiency, or the price?
7. sc07 · 1:09 to 1:26 typography
Divide the price of electricity by the price of gas, for the same amount of energy, and multiply by the furnace's efficiency: a heat pump whose average efficiency over the season, its seasonal COP, beats that number heats the home for less.
Visual. A three-line sum builds one line at a time: the price ratio, then the furnace efficiency, then the seasonal COP to beat, which holds in amber.
On screen. Electricity price / gas price / x furnace efficiency / = the seasonal COP to beat
8. sc08 · 1:26 to 1:42 data-chart
At 2024 US average prices, electricity cost 3.45 times as much as gas for the same energy, so a heat pump needed a seasonal COP of 3.28 to match a high-efficiency furnace.
Visual. Two tiles: the price ratio on the left, the break-even seasonal COP on the right, each landing as it is spoken.
| Electricity vs gas, same energy | 3.45 | 3.45 | count | EIA, state residential electricity and gas prices, lines 123-L131 |
| Seasonal COP to match a high-efficiency furnace | 3.28 | 3.28 | count | EIA, state residential electricity and gas prices, lines 123-L131 |
9. sc09 · 1:42 to 1:60 data-chart
State by state, that bar moves: in 11 states, Florida and Texas among them, a seasonal COP of 2.5 beats that same furnace, while in most of the rest it takes 3.0 or more, in places from California to New York.
Visual. Three horizontal bars, the number of states in each break-even band; the low band grows first on "11 states", the 3.0-or-higher band last and longest.
| Below 2.5 | 11 | 11 | count | EIA, state residential electricity and gas prices, lines 191-L193 |
| 2.5 to 3.0 | 10 | 10 | count | EIA, state residential electricity and gas prices, lines 191-L193 |
| 3.0 or higher | 30 | 30 | count | EIA, state residential electricity and gas prices, lines 191-L193 |
10. sc10 · 1:60 to 2:17 document-excerpt
Those are averages, and the rule leaves things out: it ignores time-of-use rates and backup resistance heat, and an average gas price includes the fixed monthly charge, which a home that keeps its gas hookup still pays and one that disconnects saves.
Visual. The EIA method note scrolls in; the line about fixed monthly customer charges highlights as "fixed monthly charge" is spoken.
Cite. EIA, method caveat
11. sc11 · 2:17 to 2:23 typography
So where you live sets the bar. Does the heat pump you buy clear it?
Visual. The question types on centred.
On screen. Does the heat pump you buy clear it?
12. sc12 · 2:23 to 2:46 data-chart
Researchers at the national laboratories NREL and Lawrence Berkeley estimated bills, at the energy prices of winter 2021 to 2022, for American homes that heat with gas and already have air conditioning, and the share that would save ranged from 38 percent to 99 percent, depending on the heat pump's performance level.
Visual. Two horizontal bars for gas homes with air conditioning: the lowest performance level short, the highest nearly full; each grows as its figure is spoken.
| Lowest-performing heat pump | 38% | 38 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 409-L415 |
| Highest-performing heat pump | 99% | 99 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 409-L415 |
13. sc13 · 2:46 to 3:04 data-chart
For gas homes without air conditioning, the shares were lower still, partly because those homes start paying to cool with the heat pump. And those shares move with energy prices: at 2019 prices, the researchers found, fewer gas homes would save.
Visual. The two bars stay; two shorter bars for gas homes without AC grow beneath them on "lower still". On s16 the whole chart dims slightly.
| With AC, lowest performance | 38% | 38 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 409-L415 |
| With AC, highest performance | 99% | 99 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 409-L415 |
| Without AC, lowest performance | 5% | 5 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 409-L415 |
| Without AC, highest performance | 58% | 58 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 409-L415 |
Cite. Wilson et al. 2024, JouleWilson et al. 2024, 2019-price sensitivity
14. sc14 · 3:04 to 3:06 typography
What happens in real homes?
Visual. The question types on centred.
On screen. What happens in real homes?
15. sc15 · 3:06 to 3:22 document-excerpt
In Britain, a study of homes that replaced a gas boiler with a heat pump found their total energy use fell by 40 percent, yet because electricity costs more per kilowatt-hour than gas, the running costs came out slightly higher.
Visual. The working paper passage; "40% decrease" marks first, then "slightly higher running costs" highlights as it is spoken.
16. sc16 · 3:22 to 3:44 data-chart
At Octopus Energy's standard prices in June 2024, that came to £190 a year more than the gas boiler, though a home that cuts off its gas connection saves about £100 a year of that: a British result at British prices, not a forecast for an American furnace.
Visual. Two tiles in pounds: the extra yearly running cost in red, the yearly gas connection charge saved by disconnecting in green.
| Extra running cost a year | £190 | 190 | usd | Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff, lines 1850-L1863 |
| Gas connection saved a year | £100 | 100 | usd | Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff, lines 1850-L1863 |
17. sc17 · 3:44 to 4:01 document-excerpt
The same working paper then looked at Cosy, Octopus's own tariff that prices electricity by the time of day, and estimated that customers who switched to it saved money against Octopus's standard tariff, most of it from shifting their use into cheaper hours.
Visual. The Cosy passage; "Switching to Cosy saves customers" highlights as "saved money" is spoken.
18. sc18 · 4:01 to 4:24 document-excerpt
In the US, an RMI model of Houston found a tariff is not enough by itself: a standard heat pump on a free-nights plan cost more than on a flat rate, and only one controlled to heat and cool ahead while power was free saved, around $1,000 in net present cost.
Visual. The RMI Houston passage; "saves around $1,000 in net present cost" highlights on "around $1,000".
Cite. RMI 2018, Houston model
19. sc19 · 4:24 to 4:48 typography
So is a heat pump cheaper to run than gas? For a gas home that already has air conditioning and gets a well-performing heat pump, the national model says it usually is; with a weaker unit, it often is not, and the more your electricity costs next to your gas, the better the heat pump has to be.
Visual. Two lines build one per clause: the first in green, the second in red.
On screen. AC already, well-performing heat pump: usually cheaper / Weaker unit: often not
20. sc20 · 4:48 to 5:01 typography
And if you have heard that a heat pump halves the bill, against gas the evidence here does not back it: the British homes cut their energy use sharply and still paid more.
Visual. A single line sets large; "still paid more" turns red.
On screen. Less energy, still paid more
21. sc21 · 5:01 to 5:12 transition
But running cost is only half of the decision; the other half is whether those savings ever pay back the price of the heat pump.
Visual. Split field: "Running cost" on the left greys out, "Payback" on the right lights up.
On screen. Running cost / Payback
22. sc22 · 5:12 to 5:25 typography
The pitch is that they do, and fast: Atlas AC tells viewers that "the increased cost to convert a gas system to a heat pump could be offset in savings by year five".
Visual. Quote card, text only; "by year five" turns amber.
On screen. "could be offset in savings by year five"
Cite. Atlas AC, YouTube
23. sc23 · 5:25 to 5:34 typography
Now picture your own gas furnace: it is not new, but it still works. Is that pitch true for you?
Visual. The question types on centred after a short hold on the empty field during s28.
On screen. Is that pitch true for you?
24. sc24 · 5:34 to 5:50 typography
The national laboratory model, and a second study by Deetjen and colleagues, set the comparison up carefully: they count only what a heat pump costs beyond replacing the old heater with a similar one, at the end of its life.
Visual. One line sets large; "extra" holds in amber.
On screen. Count only the extra cost
25. sc25 · 5:50 to 6:20 data-chart
Even on that footing, the national laboratory model found the best single option, a cheaper minimum-efficiency heat pump, came out ahead before subsidies in 55 percent of homes, and the more efficient models cost more up front, which cut the share to 41 and 21 percent. That group takes in most homes heated with oil, propane or electricity, and, of the gas homes, most of those with central air in a warmer climate.
Visual. Three horizontal bars: the minimum-efficiency heat pump first and longest, then the two more efficient models shorter, each growing as its figure is spoken.
| Minimum-efficiency heat pump | 55% | 55 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 497-L520 |
| Medium efficiency | 41% | 41 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 497-L520 |
| High-efficiency cold-climate | 21% | 21 | percent | Wilson 2024 (NREL and LBNL), heat pumps for all?, lines 497-L520 |
26. sc26 · 6:20 to 6:40 data-chart
Deetjen's study found that only 21 percent of American single-family houses would gain economically from replacing their heater with a heat pump, and that switching from natural gas rarely pays even when the old heater is due, with almost no houses in cold climates where it makes sense.
Visual. One large tile: the share of US single-family houses that would gain, landing on "21 percent".
| Would gain economically | 21% | 21 | percent | Deetjen 2021, private economics of US residential heat pumps, lines 570-L574 |
Cite. Deetjen et al. 2021Deetjen et al. 2021, by heating fuel
27. sc27 · 6:40 to 7:08 data-chart
In Britain, the same study as before put the net private cost of swapping a gas boiler for a heat pump at £4,121 over 20 years, what the household pays after a grant, and that already subtracts the boiler the household no longer has to buy. But the authors valued the Cosy tariff's savings, if they persisted, at £4,675, more than that net cost.
Visual. Two tiles in pounds: the 20-year net private cost lands on s34, then the Cosy savings value lands beside it on s35, slightly larger.
| Net private cost after grant | £4,121 | 4121 | usd | Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff, lines 1850-L1871 |
| Cosy tariff savings, if they persist | £4,675 | 4675 | usd | Bernard 2024 (NBER), UK heat pumps and a time-of-use tariff, lines 1898-L1906 |
28. sc28 · 7:08 to 7:11 transition
Which brings us to when you buy.
Visual. Wipe to a plain field with "When you buy" centred.
On screen. When you buy
29. sc29 · 7:11 to 7:46 data-chart
A Minnesota study priced a cold-climate heat pump with a propane furnace as backup at $9,450 installed: with nothing broken, that whole price was the extra cost, and the payback ran to well over a decade, depending on the furnace it was compared with. When the air conditioner alone had failed, the payback roughly halved, and when the furnace and the air conditioner both needed replacing, the extra cost fell to $370 and the payback to about a year or less.
Visual. Three tiles, extra cost of the heat pump: nothing broken first, then the air conditioner failed, then furnace and air conditioner both, the last in green.
| Nothing broken | $9,450 | 9450 | usd | CEE 2017, cold-climate heat pumps in Minnesota, lines 1376-L1408 |
| Air conditioner failed | $4,270 | 4270 | usd | CEE 2017, cold-climate heat pumps in Minnesota, lines 1376-L1408 |
| Furnace and AC both failed | $370 | 370 | usd | CEE 2017, cold-climate heat pumps in Minnesota, lines 1376-L1408 |
30. sc30 · 7:46 to 7:54 typography
Those homes ran on propane, not gas, so the years themselves do not carry over to a gas home.
Visual. One line sets large; "not gas" in red.
On screen. Propane, not gas
Cite. CEE 2017, Minnesota
31. sc31 · 7:54 to 8:21 typography
For gas homes, RMI's model finds the same exception: in many retrofits a heat pump costs more than new gas equipment, except for the customer who must replace both a furnace and an air conditioner, because a single heat pump does both jobs. And in Lawrence Berkeley's cost study, the heat pump's price premium over gas equipment disappeared once a home was getting cooling as well as heating.
Visual. A list builds one line per sentence: the RMI exception, then the Lawrence Berkeley finding.
On screen. Replacing a furnace and an air conditioner / Adding cooling as well as heating
32. sc32 · 8:21 to 8:49 typography
So does a heat pump pay for itself? For a gas home whose furnace still works, the evidence says it rarely does on energy savings alone; bought when the furnace and the air conditioner both need replacing, or when the home is adding cooling anyway, the extra cost can shrink to little or nothing, while with only the air conditioner due it shrinks but does not vanish.
Visual. Three lines build one per clause: working furnace in red, both due or adding cooling in green, only the air conditioner due in amber.
On screen. Furnace still works: rarely pays / Furnace and AC both due: little or nothing extra / Only the AC due: shrinks, does not vanish
33. sc33 · 8:49 to 9:02 typography
And even within one area, the national laboratory study found bill savings varied more from house to house than from place to place, so none of these figures is your house's number.
Visual. One line sets large and holds.
On screen. None of these is your house's number
34. sc34 · 9:02 to 9:26 typography
So before you sign, do the sum from earlier with your own prices and your furnace's efficiency, and ask the installer for the seasonal COP of the unit they are quoting. And if your furnace still works, get the quote now, and decide when the furnace and the air conditioner are both due.
Visual. A checklist builds one line per instruction.
On screen. Do the sum with your own prices / Ask for the seasonal COP / Get the quote now; decide when both are due