I am in the unenviable position being in charge of retrofiting a "no name" split unit domestic air conditioner (9000 BTU) for advanced control within an R&D project
The unit comes with adjustable speed compressor (inverter) but has a fixed capillary tube instead of an adjustable expansion valve. I want to have the valve controllable too, so I need a bypass of sorts. The controller will have an overview of the system, balancing compressor speed and valve opening.
I would appreciate some advice on the following:
- Is this conversion feasible? Would it possibly make the system unstable, e.g. end up with moist refrigerant entering the compressor?
- what type of expansion valve? There are "thermostatic" and "electronic". What would be continuously controllable, e.g. my algorithm may request 25% open. If they can both do the job I'll go for the cheaper
- I've read in this newsgroup that the compressor may need retrofiting too for a "a hard start kit" whatever this is :)
Alternatively I would need an experienced HVAC engineer to do this conversion for me, in the area of Bangor wales UK
thanks nikos