AC Infinity - SUNCORE H7 Seedling Heat Mat 52.7 × 121.9 cm

A 52.7 × 121.9 cm heat mat with a digital controller and a maximum draw of 105 W. The largest of the SUNCORE series, meant for a full shelf width rather than for a single tray.

The mat that ends up in the cold room

At this size it is rarely a corner of the living room any more. A 122 cm mat goes on a rack in a shed, a garage or a cellar, and that is exactly where the main limitation of any heat mat shows itself.

The mat makes heat on top of what is already there. AC Infinity put that at up to roughly 11 °C above ambient, and their manual says in as many words that in a cold space the mat may not be able to reach your setting. At 8 °C in the shed you will not arrive at 25 °C by asking for 25, however patiently you wait.

So work from the temperature of the room first and the mat second. A lid or a propagator dome over the trays helps more here than a higher setting does, because it holds on to the heat the mat is putting in from below.

What fits, and what it costs you in power

Along the 121.9 cm length you can line up four standard 25.4 cm seed trays side by side, with a hand's width to spare. The 52.7 cm on the short side is exactly the length of one of those trays.

Maximum draw is 105 W. On an ordinary socket that is unremarkable, roughly 0.46 A at 230 V, but count it in if the mat hangs off the same timer or power strip as your lighting and ventilation. It is the only model in this series where that sum is worth doing.

Build

Heat comes from infrared film across the whole surface, the outside is multi-layer PVC that rolls up and wipes clean, and the seams and cable entry are sealed to IP67. The controller shows the measured value next to your setting and interrupts the heating once it is reached. Put nothing warm underneath the mat and do not run the cord under a rug.

Technical Specifications:

• Model: AC-SMH7
• Dimensions: 52.7 × 121.9 cm
• Fits under: four standard seed trays side by side
• Power draw (max.): 105 W
• Current at 230 V: roughly 0.46 A, computed from the power draw
• Control: digital controller with sensor
• Band of the mat: 26.7 to 30.6 °C
• Above ambient: up to roughly 11 °C
• Heating element: infrared film
• Outer layer: multi-layer PVC, rollable
• Ingress protection: IP67, seams and cable entry sealed
• In the box: nylon storage bag, anchor and screw for the controller

Frequently asked questions

Will it work in an unheated shed?
Up to a point. The mat adds heat to the room you already have, up to roughly 11 °C above it, and AC Infinity themselves warn that in a cold space your setting can stay out of reach. Under a propagator dome you hold on to that heat far better.

How many trays fit on it?
Four side by side along the long edge, leaving about 20 cm over. A fifth will not fit.

Can I cut it down or fold it round something?
No. The film runs through the whole mat, so cutting means a dead mat. It has to lie flat and must never overlap itself.

Is it one zone or several?
One. There is a single sensor and a single setting for the full 122 cm, so everything standing on it gets the same treatment.