The AC Infinity Suncore H3 is a 25.4 × 52.7 cm seedling heat mat with a digital controller that holds the exact temperature you set. Far-infrared film spreads warmth evenly across the whole surface with no hot spots, and the IP-67 sealed mat wipes clean and shrugs off spills from the tray above it. It fits a standard propagation tray and sits neatly under the AC Infinity Humidity Dome, drawing just 20 W. Quick Bloom Lights is the official Australian importer, and this model ships with an Australian 240 V plug.
Precise warmth where germination happens
Seeds germinate faster and more evenly when the root zone is warm, and cuttings root sooner when the medium sits a few degrees above the air. The Suncore H3 does this with a digital controller rather than an on/off pad: set your target, and the display shows the mat's live temperature so you can see it settle. No guessing with a dial, and no sudden swings that can stall or rot seed.
Innovative far-infrared heating
Instead of wire coils, the mat is lined with far-infrared film that warms quickly and evenly from edge to edge. The heat is softer than a coil's, which protects seed from scorching, and every cell in the tray gets the same treatment. The quad-layer PVC is flexible, hard-wearing and rolls up for storage between seasons, and the IP-67 rating covers the seams and the cord connection, so water and dust stay out.
Getting the best from it
A heat mat adds warmth on top of the room around it: the Suncore lifts the surface by up to about 11 °C (20 °F) above ambient. In a room around 20–22 °C it reaches the mid-to-high 20s at the tray easily, which is the sweet spot for most germination. In a cold garage or shed, give it help by placing the tray inside a closed space such as a propagation tent, and always sit a dome on top to hold both heat and humidity in.
Beyond propagation, the mat is also used for home brewing and fermenting, and for gentle warmth under reptile enclosures.
Full specifications
| Manufacturer | AC Infinity Inc. |
| Product / model | Suncore H3 / AC-SMH3 |
| UPC | 819137024540 |
| Dimensions | 25.4 × 52.7 cm (10 × 20.75″) |
| Heating element | Far-infrared film |
| Heat output | Up to ~11 °C (20 °F) above ambient |
| Controller | Digital heat controller with live temperature display |
| Maximum power | 20 W |
| Voltage / plug | 240 V AC, Australian plug (Australian model) |
| Outer material | Multilayer PVC |
| Water resistance | IP-67, including cord connection |
| Certification | UL certified (E518635) · MET certified |
| Guides | User manual (PDF) |
FAQ
What temperature should I set it to?
Around 26–28 °C at the tray suits most seeds for quick, even germination, and the mid-20s works well for cuttings. The display shows the mat's own temperature; the medium sitting on it will read a little lower, so check with a probe in the tray if you want to be exact.
Will it work in a cold room?
It lifts the surface by up to about 11 °C above the room, so in a 10 °C space expect the tray to reach around 20 °C. Put the tray inside a closed space and cover it with a humidity dome and it will hold warmer, steadier temperatures.
Does it fit the AC Infinity humidity domes?
Yes. At 25.4 × 52.7 cm it matches the footprint of the Humidity Dome XL (53.3 × 27.4 cm) almost exactly, and the 40-cell Humidity Dome sits on it with room to spare.
Is it safe with water around?
Yes. The mat and its cord connection are IP-67 sealed, so drips and spills from the tray are not a problem. Wipe it down and let it dry before rolling it up for storage.
Should I leave it on once seedlings are up?
Turn it down or off once seedlings are established and have true leaves. Root-zone heat matters most during germination and rooting; after that, plants do better with normal room temperatures.