Startup · United States
Heirloom
HQ United States
Heirloom is restoring balance to our atmosphere by removing 1 billion tons of carbon dioxide. We use natural processes to engineer the world's most cost-effective Direct Air Capture solution.
Funding5 rounds · $203M
- Disclosed
- $203M
- Latest
- UndisclosedStrategic · Dec 2, 2025
| Announced | Stage | Valuation | Basis |
|---|---|---|---|
| May 26, 2021 | Seed | $31.5M | Post-money |
| Mar 17, 2022 | Series A | $243M | Post-money |
| Dec 4, 2024 | Series B | $696M | Post-money |
| Announced | Stage | Amount | Valuation | Lead investors | Other investors | Confidence |
|---|---|---|---|---|---|---|
| Dec 2, 2025 | Strategic | Undisclosed | — | Chiyoda Corporation, Development Bank of Japan | — | Confirmed |
| Feb 25, 2025 | Strategic | Undisclosed | — | United Airlines | — | Reported |
| Dec 4, 2024 | Series B | $150M | $696M | Future Positive, Lowercarbon Capital | Ahren Innovation Capital, Breakthrough Energy Ventures | Confirmed |
| Mar 17, 2022 | Series A | $53.0M | $243M | Ahren Innovation Capital, Breakthrough Energy Ventures | Lowercarbon Capital, Microsoft | Reported |
| May 26, 2021 | Seed | Undisclosed | $31.5M | — | Breakthrough Energy Ventures, Lowercarbon Capital | Reported |
- UndisclosedDec 2, 2025
- StrategicLed by United AirlinesUndisclosedFeb 25, 2025
- $150MDec 4, 2024
- $53.0MMar 17, 2022
- UndisclosedMay 26, 2021
Totals add known amounts using recorded USD conversions where available; other currencies are shown separately. A ~ marks an estimated amount.
Sources9
Profile2
- 1
Sixth-Domain · Supports Organization · country, Organization · kind
“{"country": "USA", "hq_iso2": "US", "id": "213c97fa-84eb-4f2f-9a6c-3572aca8b419"}”
- 2CompanyHeirloom
Heirloom · Supports Organization · description, Organization · name, Organization · website
“Heirloom is restoring balance to our atmosphere by removing 1 billion tons of carbon dioxide. We use natural processes to engineer the world's most cost-effective Direct Air Capture solution.”
Funding7
- 3
Heirloom · Dec 2, 2025 · Supports Funding round
“the Development Bank of Japan (DBJ) and Chiyoda Corporation have invested in Heirloom”
- 4
Axios · Feb 25, 2025 · Supports Funding round · amount
“United Airlines is investing in direct air capture startup Heirloom”
- 5
Heirloom · Dec 4, 2024 · Supports Funding round · amount
“we've closed our $150 million Series B financing round, co-led by Future Positive and Lowercarbon Capital”
- 6
Axios · Mar 18, 2022 · Supports Funding round · amount
“raised $53 million in a Series A round”
- 7
Forge Global · Supports Funding round · post money valuation usd
“Series A $52.8M $1.44 $242.5M”
- 8
Tracxn · Supports Funding round
“Its first funding round was on May 26, 2021”
- 9
Crunchbase · Supports Funding round
“Seed Round - Heirloom”
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