❄️ Boosting the Efficiency of a Single-Hose Portable AC – Up to 30% Improvement! I thought I’d share my experience in case others are facing similar issues. I have an Airwell MFH012-C41 portable air conditioner (same principle applies to Midea, Trotec, and Comfee models as well). It’s a single-hose system, which means it uses indoor air to cool the condenser and then blows the hot air outside through one hose. The problem is: this creates negative pressure in the room, which draws warm outside air back in through cracks and gaps — essentially canceling out the cooling effect. 🛠️ What did I do? I basically converted it into a dual-hose system. The original exhaust hose stayed in place, but I designed a completely new outlet for it. Both ends of the hose now have quick-release connections, so it’s easy to remove or reposition. I also made a separate intake hose, which brings in outside air directly to the condenser. That way, the unit doesn’t pull air from the room anymore — and that alone makes a huge difference. I extended both hoses so they don’t sit flush with the window. They go through a 1 mm thick pressed wood panel, mounted in the wall, with the hose openings 30 cm apart, angled 45° outward and slightly downward. This prevents the intake and exhaust from mixing and also provides some protection from rain.
📊 What were the results? I set the room temperature to 24 °C, and the AC ran for about 8 hours a day. Keep in mind, the building has virtually no insulation (just plaster walls, with standard double-glazed windows). Energy consumption comparison (in 32 °C outdoor max temp): With the original single-hose setup: ➤ 5.68 kWh/day (average over 5 days) With the DIY dual-hose mod: ➤ 3.91 kWh/day (measured over 1 day) While the dual-hose number is based on just one day, it's already showing about 30% improvement — and the cooling felt noticeably better.
🌬️ Subjective impressions: Cooling is clearly more efficient and even. No more warm air being sucked back into the room, the AC doesn’t have to work as hard, and the cool air feels more noticeable. Room layout: Living room: 4.5 × 4 m Hallway: 1.4 × 4 m Bedroom: 4.5 × 3 m The rooms are laid out in a U-shape: living room → 90° left turn into hallway → another 90° left into the bedroom. Kitchen and bathroom doors stay closed. I use a fan to circulate air between rooms, and the temperature distribution is much more even now.
https://www.printables.com/model/1348047-single-hose-to-dual-hose-ac-diy-airwell-midea-trot
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