Is variable speed marine air conditioning really worth it?
OK, I admit it. I’m a graphaholic. I can’t turn the pages of a newspaper without studying each and every graph and chart, regardless of the subject matter. I make them, I dream of them, and I get itchy if I don’t pore over a graph or two for a few days. (Today I studied one showing the rate of decline in teenage marriages in Bangladesh since 1970). But I’m also acutely aware that the accuracy of any conclusions gleaned from graphs and charts are totally dependent on the validity of the data they are constructed from. Remember; Garbage in - Garbage out.
I turned to graphs recently in my quest to ascertain whether employing variable speed compressors in self-contained marine air conditioning units (i.e. compressor, blower and other bits and bobs all together on one base) really has any great benefits, especially considering the considerable extra cost and complexity involved.
Compared to a contemporary self-contained unit, a variable speed model requires the addition of a number of special sensors plus an electronically controlled expansion valve, all feeding data into a specialized electronics package that powers a three-phase compressor.
There’s a lot to go wrong there, and no way to jury-rig an override if the electronics suffer premature death from water ingress, lightning, or even just plain ol’ electrickery.