ericmartinpe's profile - activity

It's CBECC that's creating these REVERSED surfaces automatically, not E+. E+ allows you to "share" surfaces from adjace

Could it be that one is unmet hours while occupied and the other is total unmet hours? Just speculating. This sounds lik

The ground is a significant source of heat loss, which your model ignores. You've essentially modeled a completely air-t

That sounds right. So, answering your question, the Central Cooling Design Supply Air Temperature in Sizing:System is th

That sounds right. So, answering your question, the Central Cooling Design Supply Air Temperature in Sizing:System is th

The ground is a significant source of heat loss, which your model ignores. You've essentially modeled a completely air-t

The ground is a significant source of heat loss, which your model ignores. You've essentially modeled a completely air-t

Here's one clue: ** Warning ** GetHTSurfaceData: Surfaces with interface to Ground found but no "Ground Temperatures

I would think it's the temperature at the setpoint node(s) in whatever SetPointManager is specified for that system. It

Joe Huang is an expert with weather files. His company, White Box Technologies, mostly focuses on TMY weather files, but

If you post a link to your model it might be easier to diagnose the inaccuracies. Some items that come to mind based on

If you post a link to your model it might be easier to diagnose the inaccuracies. Some items that come to mind based on

If you post a link to your model it could be easier to diagnose the inaccuracies. Some items that come to mind based on

If you post a link to your model it could be easier to diagnose the inaccuracies. Some items that come to mind based on

If you post a link to your model it could be easier to diagnose the inaccuracies. Some items that come to mind based on

The Sizing:Parameters object multiplies the heating/cooling capacities by the heating/cooling sizing factors. Looks like

Yes, you'd set the coefficients for the following curves so that they yield a value of 1 regardless of PLF/Temp/Flow (in

I don't believe there is a way to explicitly model bifacial PV in EnergyPlus. Only solar radiation incident on the norm

please report this issue on github.

Only solar radiation incident on the normal side (pointing outward, the side the right-hand rule points to) of the surfa

Are you referring to a water-to-air (water-source) heat pump cooling coil? Yes, there are a few options: Coil:Cooling:Wa

Check out PNNL's Copper tool, which can generate EnergyPlus performance curves for packaged DX equipment (and chillers)

Check out PNNL's Copper tool, which can generate EnergyPlus performance curves for packaged DX equipment (and chillers)

What command are you using to execute the simulations? I ask because if you're not using the "-p" option to specify a pr

I don't believe there is a way to model bifacial PV in EnergyPlus.

If you create your PV surface on top of the roof, it should take into account the reflectivity of the roof. From the doc

This could be due to an issue with the input files (e.g. missing OutputControl:Files or Output:Table objects) or maybe t

Can you export the rotated IDFs from DB? I suggest you do that to see how DB is rotating the building.

I'd export the IDFs from DB and compare them with a text comparison tool (e.g. BeyondCompare). See what DB is doing to r

I would model an unconditioned zone for where the air compressor is located and use an OtherEquipment object to characte

Where is the hot air coming from? You said the air source will be outdoor air. Is it coming from outside, or is it comin

The EnergyRecoveryVentilatory object contains an air-to-air heat exchanger and can be used to pre-heat/cool incoming out

Simulating a model in a different location/climate is not as simple as selecting a different EPW. You also need to modif

@Anurag_G and @Keigo you can also use PNNL's Copper tool to calculate curve coefficients.

@Anurag_G and @ Keigo you can also use PNNL's Copper tool to calculate curve coefficients.

@Anurag_G you can also use PNNL's Copper tool to calculate curve coefficients.

What are the appropriate fan curve coefficients and Fan Power Minimum Flow Fraction for the Fan:VariableVolume objects in an ASHRAE 90.1 PRM baseline model (System 5)?

I ask because there are some discrepancies between the ASHRAE/IECC code language and the Commercial Prototype Building Models. As noted in a previous Unmet Hours post, the prototype models use coefficients representing "Good SP Reset VSD Fan", which differ from the coefficients from 90.1 App G Method 2. Is this because the prototypes assume zone-level DDC where a SP reset would be required?

Regarding the "Fan Power Minimum Flow Fraction" field, both ASHRAE 90.1-2013 (6.5.3.2.1) and IECC 2015 (C403.4.1.1) state: "Low or minimum speed shall not exceed 66% of full speed. At low or minimum speed, the fan system shall draw no more than 40% of the fan power at full fan speed." I interpret this as meaning the baseline "Fan Power Minimum Flow Fraction" should be 0.66. However, the prototype models use a fraction of 0.25. What is the appropriate Fan Power Minimum Flow Fraction for a PRM baseline?

Another unrelated discrepancy I found in the prototype models for System 5 (used in medium office). ASHRAE (G3.1.1-4 Baseline System Descriptions) lists hot water boiler heating, whereas the prototypes use gas furnace heating. Are the ASHRAE prototype models not intended to represent ASHRAE ECB baseline models?

Could you just model both buildings as a single building? That way, the PV system would serve "both" building loads befo

Shaojie, if you believe this answers your question, it is customary to accept it by clicking on the checkmark (below the

Denis is correct, unexposed floors are not derated for thermal bridging. For the Medium Office prototype, only Window-Wa

The prototypes were recently updated to address Addendum av, which characterizes the new thermal bridging requirements.

Your calculation is missing the thermal bridging due to the parapet. The parapet length is the length of the roof-wall i

Your calculation is missing the thermal bridging due to the parapet. The parapet length is the length of the roof-wall i

Here is the 90.1-2022 Final Determination report.

The prototypes were recently updated to address Addendum av, which characterizes the new thermal bridging requirements.