# Heirloom

**Source:** https://www.startuphub.ai/startups/heirloom
**Profile type:** Startup

> Direct air capture startup using limestone to remove CO2 from the atmosphere at scale.

## About

Heirloom is a direct air capture (DAC) company that removes CO2 from the atmosphere using crushed limestone, which naturally absorbs carbon dioxide. Unlike liquid-based DAC approaches, Heirloom's mineral-based process is lower-cost and faster to scale. The company operated America's first commercial DAC plant and raised $150M Series B in December 2024 co-led by Future Positive and Lowercarbon Capital.

## Key facts

- **Slug:** heirloom
- **Website:** https://www.heirloomcarbon.com
- **Location:** Brisbane, California, United States
- **Founded:** 2020
- **Employees:** 100
- **Operating status:** Active
- **Total funding:** $162M
- **Sectors / tags:** Climate Tech, Carbon Removal, Direct Air Capture, Cleantech, Carbon Credits, Deep Tech, Climate
- **Social:**
  - LinkedIn: https://www.linkedin.com/company/heirloom-carbon
  - Twitter: https://twitter.com/heirloomcarbon

## Frequently asked

### What does Heirloom do?

Heirloom is a direct air capture (DAC) company that removes CO2 from the atmosphere using crushed limestone, which naturally absorbs carbon dioxide. Unlike liquid-based DAC approaches, Heirloom's mineral-based process is lower-cost and faster to scale. The company operated America's first commercial DAC plant and raised $150M Series B in December 2024 co-led by Future Positive and Lowercarbon Capital.

### What is Heirloom's revenue?

StartupHub estimates Heirloom's annual revenue at $6.0M (range $4.9M to $10.2M, 63% confidence), based on comparable companies in the sector.

### What is Heirloom's valuation?

StartupHub estimates Heirloom's effective valuation at $624.3M (range $405.0M to $972.0M, 16% confidence), based on comparable companies in the sector.

### How much funding has Heirloom raised?

Heirloom has raised a total of $162M in funding. The most recent round on record is Series B.

### Where is Heirloom headquartered?

Heirloom is headquartered in Brisbane, California, United States.

### When was Heirloom founded?

Heirloom was founded in 2020.

### What industry does Heirloom operate in?

Heirloom operates in Climate Tech, Carbon Removal, Direct Air Capture, Cleantech, Carbon Credits, Deep Tech.

### How many employees does Heirloom have?

Heirloom has approximately 100 people on record.

## JSON-LD

Structured data aligned with this page's `<script type="application/ld+json">` (included when the profile is server-rendered).

```json
{
  "@context": "https://schema.org",
  "@graph": [
    {
      "@type": "BreadcrumbList",
      "itemListElement": [
        {
          "@type": "ListItem",
          "position": 1,
          "name": "Home",
          "item": "https://www.startuphub.ai"
        },
        {
          "@type": "ListItem",
          "position": 2,
          "name": "Startups",
          "item": "https://www.startuphub.ai/startups"
        },
        {
          "@type": "ListItem",
          "position": 3,
          "name": "Heirloom",
          "item": "https://www.startuphub.ai/startups/heirloom"
        }
      ]
    },
    {
      "@type": "ProfilePage",
      "@id": "https://www.startuphub.ai/startups/heirloom#webpage",
      "url": "https://www.startuphub.ai/startups/heirloom",
      "name": "Heirloom - AI Startup Profile | StartupHub.ai",
      "description": "This is the official profile of Heirloom. Heirloom is a startup founded in 2020, operating in Climate Tech and Carbon Removal. Direct air capture startup using limestone to remove CO2 from the atmosphere at scale. Headquartered in Brisbane, California, United States. The company has approximately 100 employees.",
      "dateModified": "2026-04-13T14:13:38.130062+00:00",
      "mainEntity": {
        "@id": "https://www.startuphub.ai/startups/heirloom#organization"
      }
    },
    {
      "@type": "Organization",
      "@id": "https://www.startuphub.ai/startups/heirloom#organization",
      "name": "Heirloom",
      "url": "https://www.heirloomcarbon.com",
      "description": "This is the official profile of Heirloom. Heirloom is a startup founded in 2020, operating in Climate Tech and Carbon Removal. Direct air capture startup using limestone to remove CO2 from the atmosphere at scale. Headquartered in Brisbane, California, United States. The company has approximately 100 employees.",
      "sameAs": [
        "https://www.linkedin.com/company/heirloom-carbon",
        "https://twitter.com/heirloomcarbon",
        "https://www.startuphub.ai/startups/heirloom"
      ],
      "foundingDate": "2020-01-01",
      "numberOfEmployees": {
        "@type": "QuantitativeValue",
        "value": 100
      },
      "address": {
        "@type": "PostalAddress",
        "addressLocality": "Brisbane",
        "addressRegion": "California",
        "addressCountry": "US"
      },
      "knowsAbout": [
        "Climate Tech",
        "Carbon Removal",
        "Direct Air Capture",
        "Cleantech",
        "Carbon Credits",
        "Deep Tech",
        "Climate"
      ]
    },
    {
      "@type": "Product",
      "@id": "https://www.startuphub.ai/startups/heirloom#profile-assessment",
      "name": "Heirloom - StartupHub.ai Profile Assessment",
      "url": "https://www.startuphub.ai/startups/heirloom",
      "category": "Climate Tech",
      "description": "This is the official profile of Heirloom. Heirloom is a startup founded in 2020, operating in Climate Tech and Carbon Removal. Direct air capture startup using limestone to remove CO2 from the atmosphere at scale. Headquartered in Brisbane, California, United States. The company has approximately 100 employees. Agent Readiness score: 33/100. Full audit: https://www.startuphub.ai/startups/heirloom/agent-readiness",
      "brand": {
        "@type": "Brand",
        "name": "Heirloom"
      },
      "review": {
        "@type": "Review",
        "author": {
          "@type": "Organization",
          "name": "StartupHub.ai"
        },
        "datePublished": "2026-04-13",
        "name": "Heirloom - Profile Score 55/100",
        "reviewBody": "This is the official profile of Heirloom. Heirloom is a startup founded in 2020, operating in Climate Tech and Carbon Removal. Direct air capture startup using limestone to remove CO2 from the atmosphere at scale. Headquartered in Brisbane, California, United States. The company has approximately 100 employees. Agent Readiness score: 33/100. Full audit: https://www.startuphub.ai/startups/heirloom/agent-readiness",
        "reviewRating": {
          "@type": "Rating",
          "ratingValue": 55,
          "bestRating": 100,
          "worstRating": 0
        }
      }
    }
  ]
}
```