| Wood Species | Conventional Kiln (days) | Vacuum Kiln (days) | High-Temp (softwoods only) | |--------------|--------------------------|--------------------|-----------------------------| | Pine (southern yellow) | 3–5 | 2–3 | 1.5–2 | | Spruce | 4–6 | 2–4 | 2–3 | | Red Oak | 28–40 | 6–12 | Not recommended | | White Oak | 35–60 | 8–15 | Not recommended | | Maple (hard) | 20–30 | 5–9 | Not recommended | | Walnut | 20–25 | 4–7 | Not recommended | | Cherry | 15–20 | 3–6 | Not recommended | | Ash | 10–15 | 3–5 | 4–6 |