Vmoreno's profile - activity

This option is not in Edit calculation options --> Results, when you go to simulation screen tabs. This option is in

It depends of the programation on Model Options. If you designate Detailed HVAC and Option 2-Detailed HVAC Data in Detailed HVAC Activity data, the (Des)Humidification setpoint used are the setpoints in HVAC Zone. Otherwise, if you designate Option 1-Simple HVAC Data in Detailed HVAC Activity data, the (Des)Humidification setpoint used are the setpoints in Activity Data. You have to model (Des)Humidification process in AHUs modeled.

I recommend you seeing this text:

https://www.designbuilder.co.uk/helpv...

Hi. I have submitted one energy model for LEED Project in the last days that included PV and solar thermal system. I used the metodolgy commented by JasonGlazer, and the LEED reviewing was ok.

Hello.

You can to specify adiabatic adjacency in Construction tab, level surface.

You can to see this part of Design Builder help: http://www.designbuilder.co.uk/helpv4...

Hi @NassimJ.

I calculate PMV and PPD indexes for every hours (only summer and winter extremely week), but I evaluate only occupied hours. I calculate it hourly and calculate the mean for summer extremely week and winter extremely week. i input the valou more restrictive in BREEAM tool. The air velocity doesn´t calculate by Energy Plus, but you can use CFD module for calculate velocity vector. However, with E+ calculation you can comply this BREEAM credit.

You have to evaluate air temperature and radiant temperature, doesn´t operative temperature.

Hi @NassimJ

I have carried out Thermal comfort calculations for BREEAM requirements using Desing Builder.

You have to carry out taking into account UNE EN ISO 7730:2006. You have to calculate the PMV and PPD levels for all conditioned zones of the building evaluated. And to demostrate that values obtained are compliance wtih category B of UNE ISO 7730.

Design Builder can calculate Fanger PMV without problems. You can see the following documentation: http://www.designbuilder.co.uk/helpv4...

If I see the simulation results, the heating coil heating rate (w) shows that it value is greater than nominal capacity specified.

A colleague advise me that this issue is been studied: https://github.com/NREL/EnergyPlus/is...

Thanks by your reply. If I input the coil heating capacity, I don't known why E+ doesn't use that value. This is the problem.

Yes, you are right.

I input nominal capacity in a water heating coil definition of a AHU. I input Rated inlet/outlet water temperature and Rated inlet/outlet air temperature, too.

In a AHU sizing i input the Design supply air flow rate.

The results show that nominal capacity of the water heating coil is greater than nominal capacity specified.

Why does this happen?

How can i to fix the nominal capacity of the water heating coil?

Have you include one floor surface (or floor sub-surface) having a construction with an internal source?

Heated floors or Chilled ceiling components by virtue of the construction being selected as the floor/ceiling in a zone with heated floor or chilled ceiling defined. For example in the case of a heated floor the heated floor component must be added to the appropriate HVAC zones, but also a floor construction with an internal source must be associated with at least one floor surface in that building zone. If you set up a model with a heated floor added to an HVAC zone whose equivalent building zone has any floor surfaces with a floor construction selected not having an internal source then an error will be generated.

In Engineering Reference document - Basis for the Zone and Air System Integration, we can see:

Cz*dTz/dt = energy stored in zone air.

Cz = ρairCpCT

ρair = zone air density

Cp = zone air specific heat

CT = sensible heat capacity multiplier

Zone Sensible Heat Capacity Multiplier increases the capacitance of the air volume by increasing the zone volume that is used in the zone predictor-corrector algorithm in the simulation.

The model is a simple zone without heat internal gains, without supply and exhaust air, without HVAC... Only a box. I want to known behavior the water by solar radiation on tank.

So in equation Q = mCpAT, i can modify "m*Cp" through capacitance, and:

Air: m1Cp1=V1d1Cp1 Water: m2Cp2=V1d2Cp2

CTV1d1Cp1 = V1d2Cp2; CT = (d1Cp1)/(d2*Cp2)

Is not this a very simple approximation?

Thanks.

Is it posible to modify "Zone capacitance multiplier" in EnergyPlus for modelling different fluids (not air)? For example water in a tank placed outdoors? Thanks

Thanks David. But my question is about Thermal Collector and your net capture area.

In PV collector there is a field about Fraction of surface area with active solar cells. But in Thermal Collector there isn´t this field. So, the specified area is net or gross capture area?

Thanks

In EnergyPlus, to define the net area of a PV collector (cell surface), we can specify Fraction of surface area with active solar cells.

But to define the net area of a solar thermal collector, this option doesn´t exist. So, the area of the associated solar collector surface is used in the calculations how net catchment area?

Thanks

Hello.

I am trying to create the coefficients of performance of GSHP, using heatpump-watertowater-watertoair-spreadsheets. Excel fails to compute. Somebody can look at the data presented?

Attached the following information:

• Manufacturer's table

C:\fakepath\Manufacturerstable_Página_1.png

C:\fakepath\Manufacturerstable_Página_2.png

• Required data input table

https://dl.dropboxusercontent.com/u/8...

I haven´t flow rate data.

Thanks in advance.

I am modelling a Low Temperature Radiant Electric Systems in Energy Plus. Looking at Engineering Reference, i find documentation about "Heat Exchanger Formulation for Hydronic Systems", but documentation about Heat Exchanger Formulation for ELECTRIC Systems don´t exists. Where can i find documentation about formulation for electric systems?

Design builder (calculation engine of E+) can import models with gbxml extension.

I don't known if E+ can make it.

Various BIM software can export in gbxml extension.

If you want modelling indoor natural ventilation, you can use airflownetwork. But if you want modelling mechanical ventilation (with air treated or no) you can use plenum zone.

I use an interface of Energy Plus (Design Builder). Design Builder includes an internal calculation engine for CFD calculations. You can export the airflownetwork results and radiant temperature results of E+, and use them as limit condition inputs. Then you can make a CFD simulation and can view Airflow between zones in EnergyPlus.