I am such a DOLT! Yep the Calibration makes sense now 
Your question : Is that when you put 2480 into NumSamplesAdjusted ?
Yep: I set that variable to be 2480 then 4750, (a few more) then 17800 to get the returned time to be about 500ms
I just now put the Calibration value to 86.96, and the NumSamples to be 8900
(Full code is below)
I tested without anything running on through the CT, and got a 90% consistent 0.07 (occasionally 0.06)
I then turned the blower onā¦drum rollā¦wait for itā¦
and got a consistent 2.64 value for IRMS
Now that cant be right can itā¦ cause 123V * 2.64 A = 324 Watts 
I would be happy if the blow heater was only running at 2.64 amps as that would lower my power billsā¦butā¦ I fear thats not the case 
Full code below :
// EmonLibrary examples openenergymonitor.org, Licence GNU GPL V3
#include āEmonLib.hā // Include Emon Library
EnergyMonitor emon1; // Create an instance
//int NumSamplesAdjusted=2840;
//int NumSamplesAdjusted=4750;
//int NumSamplesAdjusted=17800;
int NumSamplesAdjusted=8900;
void setup()
{
Serial.begin(9600);
emon1.current(1, 86.96); // Current: input pin, calibration.
}
void loop()
{
//orig double Irms = emon1.calcIrms(1480); // Calculate Irms only
unsigned long first, now = millis();
//double Irms = emon1.calcIrms(1480); // Calculate Irms only
//first = millis() - now;
//now = millis();
double Irms = emon1.calcIrms(NumSamplesAdjusted); // Calculate Irms only
//Serial.print(NumSamplesAdjusted); Serial.print(" << This many samples took this many Ms > ");Serial.println(millis() - now - first);
Serial.print(Irms*123.0); // Apparent power
Serial.print(" ");
Serial.println(Irms); // Irms
}
Am starting to wonder if there is something wrong with my CTā¦ I bought two of them (the same modle at the same time) I tried the other one and I get the same results. But I wonder if I have a pair of ācloneā CTās that are not manufactured to the same standard ? They say YHDC on them and the part num looks correct (SCT013 100A 50mA)