The premise behind “micro-groove” coil construction is to continue with the standard copper-tube and aluminum fin design we all are so familiar with, but do so with smaller internally enhanced tubes that have thinner walls. This reduces the amount of copper, as well as the cost, size and weight of the coils.
Shortly after the magazine came out, I received an email from a reader pointing out the obvious — that obtaining superheat and subcooling readings usually requires the use of both gauges and a thermometer. Yes, this is true. But perhaps I should have gone on to add the following.