Espar Airtronic S3 D2L
#2 in SplitFull review
For van, truck and boat owners who want a quiet, type-approved 2 kW heater that works at high altitude. It costs much more than clones but is built to run for thousands of hours.
Amazon $1,250$1,250
The Espar Airtronic S3 D2L rates 3.5 among split diesel heaters; the Autoterm Air 2D Portable rates 3.4 among all in one ones. The Espar Airtronic S3 D2L costs $349.99 less ($1,250 vs $1,599.99).
Autoterm Air 2D Portable
#1 in All in oneFull review
For overlanders, ice fishers and boat owners who want a portable heater with a proven, type-approved core and will pay for it. Clone all-in-ones give similar heat for a fraction of the price.
Amazon $1,599.99$1,599.99
Prices were last checked October 30, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
These two sit in different type classes (split and all in one), and each is scored against the reference points for its own class, so a rating says how well each does among its own type peers. How we rank explains each factor.
| Factor weight | Espar Airtronic S3 D2L | Autoterm Air 2D Portable |
|---|---|---|
| Overall rating | 3.5/5 | 3.4/5 |
| Value 25% | 2 $568 per kW ($1,250, 2.2 kW) | 0 $800 per kW ($1,599.99, 2 kW) |
| Type approval 20% | 100 type approved (ECE R122) | 100 type approved (ECE R122) |
| Controls and safety 15% | 65 holds a set temperature, automatic altitude; no CO sensor | 50 holds a set temperature, automatic altitude; no CO sensor |
| Power draw 15% | 73 up to 27 W running | 69 up to 29 W running |
| Warranty 15% | 50 2-year warranty | 50 2-year warranty |
| Low setting 10% | 96 down to 0.8 kW | 100 down to 0.8 kW |
Specifications
| Espar Airtronic S3 D2L | Autoterm Air 2D Portable | |
|---|---|---|
| Heating | ||
| Heat output (maker) | 2.2 kW | 2 kW |
| Lowest output | 0.8 kW | 0.8 kW |
| Fuel burn | 0.1 to 0.27 L/h | 0.1 to 0.24 L/h |
| Build | Split (installed) | All in one |
| Power | ||
| Supply | 12V | 12V |
| Running draw | 6 to 27 W | 10 to 29 W |
| Starting draw | 90 W | - |
| Controls and safety | ||
| Thermostat | Yes | Yes |
| Automatic altitude | Yes, to 13,120 ft | Yes, to 13,780 ft |
| App | - | No |
| Timer | - | No |
| Remote | - | No |
| CO shutoff | No | No |
| Type approval | ECE R122 | ECE R122 |
| Build | ||
| Dimensions | 12.2 x 4.5 x 4.8 in | 24 x 16.5 x 19 in |
| Weight | 5.5 lb | 25.5 lb |
| Warranty | 2 years | 2 years |
| Released | 2021 | - |