Reviewer Profile
One-Year Performance Summary
Visual Highlights
Cooling Performance: About a year after installation, the AC kept John's roughly 14-by-7-foot insulated rear camper near 73–74°F on a South Carolina day with a heat index around 110°F,the air coming out is 46.5 °F.(5:25)
On-Road Cooling: On a drive of about six hours across South Carolina, the AC maintained roughly 76°F in the rear camper on a medium setting despite 95°F outdoor temperatures; solar and engine input charged the batteries along the way.()
Noise Level: Very Quiet - John found the AC very quiet from his bed: on turbo, it registered 66–70 dB near the unit, but about 47 dB roughly five feet away at the bed.(10:47)
Power Consumption: During his year-later power test with solar input shut off, John recorded about 375 W after settling on low, 446 W on medium, and a brief peak of approximately 760 W on turbo.(7:43)
Off-Grid Runtime: During his daughter's warm, humid overnight stay, the AC operated for about 12 hours with no solar input, using around 55% of the camper's 314 Ah lithium battery capacity.()
Solar-Supported Cooling: At the one-year follow-up, John's 780 W rooftop solar setup brought in more power than the AC was using in full sun, so the batteries were charging while the interior stayed cool.(1:49)
Recommendation: A year after installing the AC, John describes it as a game changer for traveling and camping in South Carolina and the Southeast without relying on electrical hookups.(12:01)
Detailed Analysis
An ambulance conversion designed around off-grid travel
John Woolworth and Lin turned a 2002 ambulance into a camper they could take off-grid. Living and traveling in South Carolina made air conditioning especially important, but they wanted to power their setup from batteries, solar, and energy available while driving rather than depend on campground hookups. They chose a 12V, 10,000 BTU OutEquipPro air conditioner and mounted it on the ambulance roof.
The unit cools a rear living area measuring roughly 14 by 7 feet. The walls and ceiling have a couple of inches of insulation, while the aluminum floor has relatively little. John also keeps the door to the front cab closed to avoid trying to cool the sun-heated windshield area. Those details matter to the results: this is a comparatively compact, insulated space, not an uninsulated full-size bus.
In his original installation video, John found the air conditioner itself straightforward to fit. He cut his own roof opening and described compatibility with a standard 14-by-14-inch opening or one as small as 14 by 9.5 inches. The kit he received included 12 feet of 6-gauge wire, enough for his run to the electrical system. Preparing the ambulance ceiling and routing the bulky electrical connector through a separate roof opening took extra work, and that penetration needed careful sealing.
A year later, cool inside despite South Carolina heat
At the follow-up about a year after the installation, John estimated the outdoor heat index at roughly 110°F. Inside the rear camper, the temperature hovered around 73–74°F as the AC ran. During a check at the outlet, his infrared thermometer displayed approximately 46.5–47°F. He was especially pleased that the cabin remained comfortable in the hot, humid conditions that had motivated the purchase.
The benefit extended to travel days. On a roughly six-hour drive across South Carolina a few weeks before the follow-up, the outdoor temperature was about 95°F. With the AC running at a medium setting, the rear compartment stayed around 76°F. Solar and engine power also charged the batteries during that drive, making cooling practical while the ambulance was moving.
Power readings that help him balance cooling and battery use
John's year-later system had 314 Ah of 12V lithium batteries and 780 W of rooftop solar. To check electrical draw at different settings, he temporarily switched off the solar input and watched his battery-monitoring app. On the lowest fan setting, the reading began around 400 W and settled near 375 W while maintaining the cabin temperature. A slightly higher fan setting drew about 388–390 W, and a middle setting drew approximately 446 W.
The next-to-highest setting registered about 525 W. The highest setting later showed around 663 W, while an earlier turbo test briefly peaked at about 760 W as the compressor ramped up. These were readings at different points in the test, not one fixed power requirement. At 77% battery charge and roughly 446 W on medium, John saw an estimate of a little over seven hours without solar input. That is why he generally favors a mid-range or lower setting over leaving turbo on for long periods.
An overnight example and sound levels from the bed
On a warm, humid night, John's daughter stayed in the camper while the air conditioner ran for about 12 hours. With no solar input during that period, it used roughly 55% of the total battery capacity. John also noted that the compressor stops when the selected temperature is reached, leaving air circulating through the camper. That cycling helps the system conserve battery power as it maintains a comfortable interior.
He also checked the sound level at different positions. At the lowest fan setting, the reading was about 46–50 dB from roughly a foot away when he stopped talking. On turbo, it reached approximately 66–70 dB near the unit, but registered about 47 dB from the bed, roughly five feet away. From that sleeping position, John described the sound as very quiet.
Running the AC while charging—and making the most of the setup
One of John's favorite results is being able to cool the camper without necessarily draining the batteries. During the sunny one-year follow-up, the 780 W solar array was bringing in more power than the running AC was using, and the batteries were still charging. The six-hour drive offered another example: with solar and engine charging available, the rear area stayed cool while battery charge increased.
John recommends starting the AC earlier in the day, before the inside of the vehicle heats up, and giving insulation and heat gain serious attention. He also recognizes the tradeoff between parking in sunlight for rooftop solar and parking in shade for a cooler interior. He had obtained a second MPPT controller and planned to add off-rig solar panels, with the goal of parking the ambulance in shade while placing the panels in the sun.
About a year after installation, John still speaks enthusiastically about the 12V system. For his small, insulated ambulance camper, it has made hot-weather travel in South Carolina and the Southeast more comfortable while preserving the off-grid flexibility he and Lin wanted from the start.
