I'm running some simulations by asking EnergyPlus (through the IDF) to output Output:Meter,Electricity:HVAC (an output meter which measures the electric energy consumption in Joule).

If I choose an 'hourly' reporting frequency, like this:

Output:Meter,Electricity:HVAC,hourly; !- [J]

I guess that I can obtain Wh from J in this way:

Wh = J / 3600 s,

E.g.: 4 J ==> 0.11111 Wh

But, if I choose a reporting frequency equals to 'timestep', like this:

Output:Meter,Electricity:HVAC,timestep; !- [J]

where 'timestep' = 4 (so there are 4 timesteps per hour, hence I have 15-minutes timesteps):
how can I convert that value of energy measured in Joule (but "sampled" every 15-minutes) to a value measured in Wh?

Is it sufficient to divide it by a factor of 3600, and then divide it by 4 (n°timesteps per hour), to finally obtain an energy value expressed in Wh?