Does anyone have experience using TREAT to model mid-rise (3-story) apartment buildings with interior corridors? Our housing authority requires true-ing up the "calculate model" heating load consumption to the "calculate billing" heating load consumption. TREAT's analysis of the monthly consumption figures come out with a baseload that's too high and heating load that's too low (8 kBTU/SF), I say this is based on temperatures observed during the site survey which show that the seniors in this complex have heat on year round. When I change the thermostats to 75 and the heating season to year round the model's heating load goes up, but of course, the billing analysis does not change and then I can't true up.
I need to have additional justifiable rationale for them to accept my base and heating loads over TREAT's (in addition to my observed conditions). Has anyone had to do this and does your experience show the same problem with mid-rise, interior corridor buildings? do you know of any third party info to support me?
I do not have this problem at all with apartment style or townhouse style buildings.
Where is this going? Are you (the housing authority) trying to set the Utility Allowance? Somewhere else?
All electric? Balanced Power? Does each apt have specific DHW, heat and cool? Are they metered individually? or some type of master meter system? What size are the apts and what climate zone? Are you getting the same results for a top floor end unit as a middle floor middle unit?
Hi John - I'm strictly modeling the entire building, not individual units. I'm looking for a justifiable rationale to increase heating load to a more realistic level (based on observed apartment temperatures and my experience) to increase savings and obtain rebates for the housing authority (SIR>1) but TREAT picks an unrealistically low heating load based strictly on its billing analysis and it does not consider tenant behavior, setpoints, etc in that billing analysis. I'm looking for anyone else's experience with this issue...
This isn't uncommon -- senior buildings often have lower-than-typical baseload use; especially for domestic hot water.
More generally, though -- TREAT DOES have inputs for t-stat settings, water heater settings, space heating schedules, etc. I haven't used it heavily for a few years (We used v. 3.3.1 -- the current version is 3.5). But even that had tweaks for ridiculously detailed inputs -- whether there were dishwashers, which are more efficient than hand-washing dishes, not just t-stat setpoints, but also inputs for setbacks for heating and A/C, inputs for plug load as well as hard-wired electric loads, and on and on.
The process of truing up a model in TREAT can be ENORMOUSLY educational. After all, the utility bills don't lie... Read through the documentation enough to find out what you aren't accounting for, and make that true-up process work for you the way it's supposed to...
So why is tenant behavior significantly different in this building?