Physicist here. I'm confused why you are using the enthalpy of fusion in your calculation, since your project does not appear to be freezing the water after condensation. Also, you seem to be using the enthalpy of vaporization from boiling at 100 C in your calculations, which is incorrect for use around 30 C.

A better way to calculate your energy needs would be to look at a steam table, such as the one on Wikipedia's water data page, then take the deltaHvap. This is the accurate enthalpy of vaporization. https://en.wikipedia.org/wiki/Water_%28data_page%29

In theory you need to add the amount of energy to cool the air/vapor mixture to the dew point. However, this amount will likely be small enough to be within your experimental error. For low humidity applications (like Burning Man), you can assume you are cooling mostly air, which is around 1.2 Joules/K per m^3. At 30 K temp differential, and humidity of 4 g/m^3, this is only 9 joules per gram water, or pretty much negligible.

So, you are looking at a deltaHvap of around 2420 to 2450 J/g in this temperature range. This is reasonably close to your original estimate of 2590 J/g, and the good news is that the error is in your favor.