More Btu can be stored (or released) in energy storage systems thanks to the "phase change" energy.
To determine the savings, we need to compare the fuel consumed before and after the retrofit.
Before the retrofit, if the boiler is only 50% efficient, then the fuel supplied to the boiler will be more than the 10,000 MMBtu needed for the process. Thus, the fuel input will be 10,000/.5
= 20,000 MMBtu per year.
After the retrofit, the new boiler is 80% efficient and the fuel input will be 10,000/.8
= 12,500 MMBtu per year.
The Savings would be:
= 20,000 MMBtu – 12,500 MMBtu
= 7,500 MMBtu per year.
Because there are no energy performance statistics for the new portion of the building, IPMVP Option D is helpful in this situation. Option D enables simulation in order to determine baseline and "avoided expenses" associated with making energy improvements.
Because colder air is denser and dryer, it requires the compressor to operate less and is therefore more efficient.
Enthalpy in the gaseous state (hg), which is equal to 1201 Btu/lb, may be calculated using the Saturated Steam tables.
Flue gas temperatures that fall below the dew point will cause condensation. (Let's hope your boiler is a condensing one.