Quick verdict
A 1,500 watt PTC ceramic fan heater with an independent plug-in thermostat, three speeds and overheat protection, rated at about 6,800 BTU, that holds a small greenhouse above freezing and circulates and dries the air as it does. PTC elements self-regulate and do not glow, which suits a damp space full of plants. Fifteen hundred watts is the limit of a household circuit and heats roughly a 6 by 8 greenhouse in a mild winter; a large or leaky greenhouse needs more. Use a GFCI outlet and keep it off the floor.
Strengths
- Thermostat holds a set temperature and saves power
- PTC ceramic element self-regulates and has no exposed glow
- Fan circulates air and reduces damp
- Three speeds and overheat cutoff
- Fifteen hundred watts from a standard outlet
Weaknesses
- Fifteen hundred watts suits a small greenhouse only
- Electric heat is costly over a cold winter
- Must be kept dry, elevated and on a GFCI outlet
The overall YardToolLab Score is out of 100. Section scores are out of 10.
Keeping the Frost Out of a Small Greenhouse
A greenhouse holds a few degrees over outside on a still night and none in a wind, and the tender plants inside die at the first hard frost. A thermostat-controlled heater holds the line. VEVOR’s is a 1,500 watt PTC ceramic fan heater with a separate plug-in thermostat, three speeds and overheat protection, sized for a small greenhouse on a standard outlet.
This review is based on the maker’s specifications and on how electric greenhouse heaters perform generally. We have not used this heater ourselves.
Sizing
Fifteen hundred watts, about 6,800 BTU, is what a household circuit gives. In a mild winter it holds a 6 by 8 foot twin-wall greenhouse a few degrees above freezing; in a hard winter or a single-glazed house it falls behind. Bubble wrap on the glazing and a low target temperature stretch it. A big greenhouse wants a 240 volt heater or gas.
The Thermostat
The heater plugs into the thermostat unit and the thermostat into the wall. Set the target, hang the sensor at plant height away from the heater and the heater runs only when the greenhouse falls below the setting. That is what makes electric heat affordable: it runs for the cold hours, not all night.
PTC and Fan
PTC ceramic elements limit their own temperature and have no glowing wire, which is the right technology for a damp space. The fan moves warm air through the house and dries foliage, which reduces the grey mould that still winter air breeds. Three speeds balance noise and throw.
Safety
Water and electricity share a greenhouse. Plug into a GFCI outlet, stand the heater on a shelf or bricks off the floor, keep it away from where you water and never drape anything over it. The overheat cutoff is a backstop, not a licence.
Who Should Buy It
- Owners of a small greenhouse overwintering tender plants.
- Seed starters keeping a greenhouse warm in early spring.
- Anyone with power at the greenhouse and no gas.
Common Owner Complaints
Not enough for a large house and the electricity bill. Size honestly; insulate and set low.
Setup Tips
Place the heater at the far end from the door so warm air travels the length of the house, aimed along the bench, not at the plants nearest it. Hang the thermostat sensor at plant height in the middle of the house, shaded from the heater’s airflow and from morning sun. Set the target a couple of degrees above the plants’ minimum, not higher, since every degree costs power all night.
Alternatives to Consider
Bio Green Palma heaters with a built-in thermostat. A propane greenhouse heater for off-grid sites. A seedling heat mat to warm the plants rather than the air.
Verdict
For a small greenhouse with power, a PTC heater on a thermostat is the safe, controllable way to keep frost out, and this kit includes the thermostat. Insulate the house, set the target low and elevate the heater.
Full specifications
VEVOR 1500W PTC Greenhouse Heater with Independent Thermostat, 3 Speeds and Overheat Protection FAQs
About 6 by 8 feet in a mild climate, holding a few degrees above freezing. Larger greenhouses, hard winters or single-glazed houses need more watts or insulation.
The heater plugs into the thermostat and the thermostat into the outlet. Set the target and it switches the heater on below it and off above. Place the sensor at plant height away from the heater.
PTC elements run cooler than wire coils and do not glow. Still, keep it off the floor, away from watering and on a GFCI outlet, and never cover it.
Fifteen hundred watts is 1.5 kWh for every hour it runs. The thermostat keeps that to the cold hours; insulate the greenhouse and set the target low to limit the bill.
