Good evening all,
So we're beginning the transition from VDOE (DOEv2.1e) to eQuest
(DOEv2.2), and we noticed that eQuest tended to result in higher space
heating requirements. We have attempted to reconcile the difference, but
even when we set two baseline buildings as closely as possible in their
respective program - setting as many details the same as we could - we
still couldn't get similar space heating results. Most of electric
consumptions were close enough, however the space heating section
results indicated about a 40% more heating in eQuest than in VDOE. The
eQuest model is showing about 0.67 therms/square foot for something
similar to an ASHRAE baseline (although it's not exactly) which seems
high.
In a similar fashion, I'm working on a NAPA autoparts store, which, as
most know, are extremely simple. My output there is about 0.76
therms/square foot. I built it to the dimensions that they gave me,
however I set all the components to the ASHRAE 90.1 standard and left
the remainder as defaults.
Has anyone else experienced this?
Eric O'Neill
Did you have a look at infiltration values, schedules and calculation
method (effects of outside T and V)?. Since Std.90.1 does not fix this
values both programes could be using different defaults with a
significant impact on heating demand.
*Xavier Garc?a Casals*
Our infiltration values and schedules are both set the same. Would you mind elaborating on what you mean by calculation method?
We've tried to analyze the loading to see if the heating calculation is the same; however report sheet LS-D from each program is for a specific hour of a day and of course the peak load happens on different days at different times of the year which means you're comparing red delicious apples to granny smiths. We're going to be parsing the 8760 data from the hourly reports at some point to see if we can't figure out if the internal loads are different, if a specific shell component is yielding significant losses, or if the whole building is just being calculated differently. I was just hoping someone might have some insight into what's going on and could point me in the right direction.
Thanks,
Eric
I have done a comparison between DOE2.1 and DOE2.2 for an office building with a boiler and chiller serving a VAV air handler. Heating and cooling loads were almost identical between the two (as listed in the SS-A reports). Boiler gas consumption was about 10% lower for DOE2.2.
Doug
Maybe you can create a hourly report in eQUEST including HVAC system and thermal zone as variable types to check the real conditions of the HVAC systems.
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The hourly results series I always pick up are as follow
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total central heat coil output
toal central?cool coil output
total system supply air flow
total system return air flow and,
ratio of outside air to total supply air.
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I think the hourly report is very useful for troubleshootng specially for unexpected cooling or heating loads.
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HTH
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Shaojie
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