Paul and the rest of the user group,
The attached presentation was a great tool to both confirm and improve our
approach for modeling VRF. I do have a follow-up question/problem that
arose during the excel work (Slides 33 and 34 of the presentation).
*Question:* Has anyone ever followed this approach and found out that the
results from the hourly report are significantly different than the "monthly
and annual energy consumption by enduse" reports that eQuest generates?
*Step-by-step explanation of my process:*
I created an hourly report exactly as in the presentation with the electric
input to both heat and cool for every system in the facility along with an
hourly report for the building as a whole. When I add up the heating energy
and cooling energy of the individual systems, it equals the heating and
cooling energy for the whole facility, so far so good.
Next, we looked at this heating and cooling energy and compared it to the
"monthly and annual energy consumption by enduse" report that eQuest spits
out. These numbers were not in agreement. For example, according to the
hourly reports, the electricity used for space heating is 18,615 kWh while
the space heating electricity in the "monthly energy consumption by enduse"
report is 10,930 kWh. Big difference.
In some modeling programs (cough, Trace), I've seen heat pumps output the
combination of their energy in either space heating or space cooling and not
differentiate (which appears to be happening in eQuest as our space cooling
energy is going up in the winter with the VRF system... and the building is
definitely in a heating-dominated climate and has little internal space).
The combination of the hourly report heating and cooling energy was 74,224
kWh and according to the "monthly energy consumption by enduse" report, the
combination is 64,330 kWh.
I tried adding in the "HP Supp" energy and some other uses from
the "monthly energy consumption by enduse" report to no avail. I've had
another eQuest user check my excel calculations and my hourly reports and
they seem to be in good working order.
Any guesses, suggestions, strong reactions?
