Coal fuel type not available in Coil:Heating:Fuel

[yzhou601]

Issue overview

E+’s Coil:Heating:Fuel object doesn’t support Coal fuel type for some reason. But some other objects with fuel type options do. From the Energy+.idd:

OtherEquipment	Coil:Heating:Fuel	Boiler:HotWater	WaterHeater:Tank
\key NaturalGas	\key NaturalGas	\key NaturalGas	\key NaturalGas
\key Propane	\key Propane	\key Propane	\key Propane
\key FuelOilNo1	\key FuelOilNo1	\key FuelOilNo1	\key FuelOilNo1
\key FuelOilNo2	\key FuelOilNo2	\key FuelOilNo2	\key FuelOilNo2
\key Diesel	\key Diesel	\key Diesel	\key Diesel
\key Gasoline	\key Gasoline	\key Gasoline	\key Gasoline
\key Coal		\key Coal	\key Coal
\key OtherFuel1	\key OtherFuel1	\key OtherFuel1	\key OtherFuel1
\key OtherFuel2	\key OtherFuel2	\key OtherFuel2	\key OtherFuel2

Is there any specific reason that coal is excluded in Coil:Heating:Fuel object? source code and idd is limiting its use, while the docs, is inconsistently specifying coal as a valid option. Can we add Coal as a valid option?

Details

Some additional details for this issue (if relevant):

• Platform (Windows, 10)
• Version of EnergyPlus (9.3.0)
• Unmethours link or helpdesk ticket number

Checklist

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• [ ] Defect file added (list location of defect file here)
• [ ] Ticket added to Pivotal for defect (development team task)
• [ ] Pull request created (the pull request will have additional tasks related to reviewing changes that fix this defect)

[mjwitte]

At the time this was converted from Coil:Heating:Gas to Coil:Heating:Fuel, coal was probably excluded, because it's hard to envision an actual piece of equipment like this. But I don't see a problem allowing it here, even though it may never be used that way.