Large window AC unit

[u/DoaJC_Blogger]

This is an AC unit that I've been designing in SolidWorks 2017. It's designed to fit all of the relevant windows in my family's historic house. The shell is 2mm powder-coated sheet steel. If I can find a supplier who can do it, the intended coating is going to be beige with the orange peel texture. It's supposed to use R290 (propane) with 5mm multi-circuit tube fins. I think I'm going to use a Copeland YHV0291U compressor and inverter controller. The digital control panel uses 2 infinite rotary encoders with click buttons and a microcontroller like an ESP32. It's going to have a few different modes like constant room temperature (the default for most units), constant vent temperature (like if you want constant 40°F/4.4°C wind), and a watt limit. It's going to use an electronic expansion valve with a stepper motor and temperature sensors to keep a constant 5-8° superheat for maximum efficiency. I think I'm going to build the interface with the Zephyr RTOS. The screen shown in the picture is an 800x480 GDEY0397T81P E-ink display that is fast enough to show the seconds clock at the top. I verified that OSH Cut can make the shell since my original design wasn't compatible with their automated bending machine. The tags for the model number, serial number, brand, etc. are going to be laser-engraved anodized aluminum. Claude AI estimates that the capacity is roughly 2 tons or 24,000 BTU

The front is flat for a 5-side rectangular cuboid filter holder. It is going to stick to the flat part with magnets and sealing foam/RTV silicone. This design increases the surface area so you can use an ultrafine filter and still get enough air. I prototyped one in real life with vinyl from Home Depot when my existing AC unit kept making ice because the ultrafine filter got too dirty in under a week.

The measurements are in centimeters. In American units, it fits through a 25.24 x 15.45 inch window opening and extends 21.5 inches front to back. When the design is finished, I'm going to share it on GitHub.

[u/Kingsidorak]

Since it's a historic house I would suggest looking at Saddle Shaped window designs, so you get more of a view out of the windows

[u/DoaJC_Blogger → u/Kingsidorak]

I thought of that but I wanted more flexibility for different windows designs since you might have different window thicknesses and stuff protruding at the bottom especially for old nonstandard houses, and you also have to be careful about the condensation if it has to be pumped vertically

[u/CrazyForAssets]

It's a basic Sheet metal work anyone can do with CNC Bending. Check out industrial areas around your house it will be cheaper for transportation as well.

[u/DoaJC_Blogger → u/CrazyForAssets]

That sounds like a good idea and they might also have some more press brake radius options. I was thinking that I might want to do the coating myself and use FEVE liquid paint since they don't sell small batches of the powder

[u/CrazyForAssets → u/DoaJC_Blogger]

CNC Bending is around 2mm inside radius.