Bundled with the BioGreen Thermo 2 controller, which is most of why this is the interesting purchase.
Best Bench Heater Dr. Infrared Heater DR218 1500 W Greenhouse Infrared Heater with BioGreen Thermo 2 Digital Thermostat
~$178
A 1500 W IPX4 infrared heater bundled with the BioGreen Thermo 2, a digital greenhouse thermostat that switches heating and cooling appliances from one controller.
Check price on AmazonSpecifications
| Heater output | 1500 W, single setting |
|---|---|
| Heater coverage | Manufacturer states 150 sq ft |
| Heater protection | IPX4, protected against splashing water |
| Heater form | Light weight and portable |
| Controller | BioGreen Thermo 2 digital greenhouse thermostat |
| Controller range | -58 F to 108 F |
| Controller protection | IPX4 |
| Controller function | Dual thermostatic control, switches heating in winter and ventilation in summer |
Specifications above come from the manufacturers' published feature lists for the two bundled items. Treat pricing as approximate, since Amazon pricing moves.
What it does well
- Infrared warms surfaces rather than air, so the heat lands on pots, benches and soil instead of on the air that leaks out through every panel joint. In a leaky structure that is a real efficiency argument.
- Root-zone temperature drives germination and early growth far more than air temperature does, and a radiant source above a bench is one of the few ways to raise it without heat mats under every tray.
- The bundled Thermo 2 is the part that makes this sensible. A heater without an external thermostat runs on a dial and either wastes energy or fails to hold a minimum.
- The Thermo 2 switches cooling as well as heating, so the same controller that runs the heater on a frosty night can run an exhaust fan on a hot afternoon.
- IPX4 on both the heater and the controller is the right rating for a space where you are watering overhead, and it is the specification most workshop heaters do not have.
Where it falls short
- Infrared only heats what it can see. Anything shaded by a bench, a pot or a plant gets no direct radiant gain, so the coverage figure describes a footprint under the unit rather than a whole house held above freezing.
- 1500 W is 5,100 BTU. That is a modest heater by any measure, and on a leaky 150 sq ft house in a hard frost it will run continuously and still not hold a large lift over outside air.
- It has one setting. There is no low stage, so on mild nights it is either full output or off, which swings the temperature more than a two-stage unit would.
- This is a bundle of two products from two makers, so the fit is by intent rather than by design. Expect to mount and wire them as separate items.
- Radiant heat close to foliage can scorch. Mounting distance matters, and a unit set too low over a bench of seedlings will cook the tops while the compost stays cold.
What owners report
The consistent finding in owner reports across radiant greenhouse heaters is that they suit a defined area rather than a whole structure. Growers using them over a propagation bench or a specific block of pots are satisfied; growers who expected 1500 W of infrared to hold an entire house above freezing are not. That is physics rather than a defect, and it is worth deciding which of those two jobs you are buying for. Our oil-filled radiator versus fan heater comparison covers the two air-heating strategies if whole-house warmth is what you actually need.
The Thermo 2 draws better comment than the heater does. Growers rate the dual heating and cooling control highly, because a single controller running a heater on a frosty night and an exhaust fan on a hot afternoon is exactly what a greenhouse needs and exactly what a built-in heater dial cannot do. Our heater thermostat versus external controller comparison explains why sensor placement, not sensor accuracy, is usually the thing that decides how well a greenhouse holds temperature.
Third, sizing and expectations. 5,100 BTU is a small heater and it is the right heater for a great many domestic greenhouses. Establish the requirement rather than guessing: put your footprint, glazing, target minimum and local design low into the heater BTU calculator. If the answer is well above 5,100 BTU, the honest recommendation is to insulate first and then look at our Bio Green Phoenix review for the larger unit.
Who it suits
- Growers who want a specific propagation bench kept warm rather than a whole house heated.
- Anyone who does not yet own a greenhouse thermostat, because the bundled controller is worth most of the price difference.
- Growers with leaky structures where warming air is throwing money out through the joints.
Who should skip it
- Anyone needing a hard frost held off a whole 150 sq ft house, which is more than 5,100 BTU can do.
- Growers who want low and high stages, because this heater has one setting.
- Anyone mounting it close over tender seedlings without checking the clearance, because radiant heat scorches.
Alternatives worth considering
Whole-Air Alternative Bio Green Palma 1500 W Greenhouse Heater with Digital Thermostat
~$161
The same 1500 W of energy delivered as moving warm air, with two stages at 750 W and 1500 W and a thermostat built in. Better for holding a whole small house above a minimum; worse for warming a specific bench.
Check price on Amazon
Step-Up Alternative Bio Green Phoenix 2.8 kW 240 V Greenhouse Heater, 9,553 BTU
~$290
Almost twice the output with two switchable stages, for houses past roughly 150 sq ft. It needs a 240 V circuit, which is the reason most people cannot simply buy it instead.
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Budget Pick PELONIS Oil-Filled Electric Radiator, 1500 W
~$80
The same 1500 W as silent radiant and convective heat from a mass that keeps giving after it cycles off, for half the money. It has no greenhouse-grade splash rating, so keep it away from overhead watering.
Check price on AmazonKeep reading
- Oil-filled radiator vs fan heater
- Heater thermostat vs external controller
- Greenhouse heater BTU calculator
- Germination soil temperature chart
- Bio Green Palma 1500 W review
- Bio Green Phoenix 2.8 kW review
- Best greenhouse thermostats and controllers
This review draws on published specifications, manufacturer figures and the consensus of verified owner reviews. We have not tested this product ourselves, and we say so rather than implying otherwise. As an Amazon Associate we earn from qualifying purchases.