Calculating Heat Loss for Improved Efficiency in a Steam Generator Design

[Jt2015]

At current I am trying to redesign a steam generator as seen in the picture attached, the requirements for this are as follows:
· The water contain must have a minimum capacity of 2.25 litres
· The heat loss as boiling point shall not exceed 75W in ambient of -3 C +/- 1 C
· The fan shall have a capacity of 0.07 to 0.10m^3/min at 0.5 mbar static pressure
· Six steam outlets holes shall be positioned at the top of the generator around the perimeter spaced at equal distances
· The generator should be calibrated at -3 C +/- 1 C to give reading for each 70 +/- 5g/h output up to a maximum of n times this figure where n is the maximum number of seating positions designated by the manufacturer.

Having not studied physics I am struggling to find what calculations would be required in order to calculate the heat loss and therefore cannot try improving it.
The dimensions for the base are not set and can be altered, only the nozzle and dispersion chamber have set dimensions.

If somebody could point me in the right direction to what equations I will need that would be great,

Thanks

 

[Bystander]

70 +/- 5g/h output

Grams? Or, gallons?

 

[Jt2015]

Grams? Or, gallons?

Sorry, it's grams per hour

 

[Jt2015]

Here's the requirements for the nozzle and chamber too.

 

[SteamKing]

Here's the requirements for the nozzle and chamber too.

I don't think this device is a steam generator in the conventional sense, more like a vaporizer or a tea kettle. 70 g an hour is equivalent to converting about 5 tablespoons of water to vapor.

 

[Jt2015]

I don't think this device is a steam generator in the conventional sense, more like a vaporizer or a tea kettle. 70 g an hour is equivalent to converting about 5 tablespoons of water to vapor.

Yeh that's a problem I've had as regards to research into it, there's not much information on them. I've literally called it that because that's what it is listed as in the guidelines.

Effectively it is just a kettle heating element in an aluminium (Previous machine) casing lined with insulator, with the nozzle, chamber and fan on top.
I just have little knowledge on what calculations I need to work out the heat loss through it in order to then improve the efficiency for the design as currently the method for this has been just add more insulator.