Re: [EnergyPlus_Support] Re: Ideal Loads Latent Cooling Rate

You will see no latent load when you have no outside air and no latent load in the room, or when you have outside air dry enough to compensate for moisture created in the room. I don't think you should see latent load in winter with no humidity control.

Very good source of info about this subject is ASHRAE Fundamentals Chapter one.

Best,

Santiago.

2013/2/25 simonflorian2002 <f.simon.mail@xxxxxxxxx>

With an Ideal Loads System, you will specify the temperature (Â°C) and the Maximum Heating Supply Air Humidity Ratio and the Minimum Cooling Supply Air Humidity Ratio.

If you set correctly these values you should find a situation where you donâ??t need to humidify or dehumidify, furthermore if you set the Fields â??Dehumidification Control Typeâ? and â??Humidification Control Typeâ? to none.
Thus the latent load for the room should be to zeroâ?¦

Why canâ??t I have this result ?

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "jeannieboef@..." wrote:
>
> With an Ideal Loads simulation, you will specify the air (deg C) and
> absolute humidity (g water/g dry)
> This means that the simulation will compare these two properties to those of the outdoor air conditions so as to deturmine how much the air needs to be heated or cooled, humidified or dehumidified to reach the delivery air conditions that you specified.
>
> Latent load = energy of the water if the zone were at perfect design setpoint conditions (which you specify or which the program may assume) -
>
> the energy of the current water amount at the current timestep zone temperature.
>
> As people and other things can add or subtract water to the zone, the Latent Load may fluctuate.
>
> Right?
>
> Sent from my iPhone
>
> On 22.02.2013, at 16:35, "simonflorian2002" wrote:
> > Dear E+ User,
> >
> > I have some difficulties to understand how is calculated the latent Energy/Rate for Ideal Loads air System. I'm using such a system, with humidification and deshumidification set to none, and yet, I found a "Ideal Loads Latent Cooling Rate". I thought that, with this setting, the sensible and latent cooling rates are the same, why are they different ?
> >
> > Thank you.
> > Florian
> >
> > ZoneHVAC:IdealLoadsAirSystem, Bloc1:Zone1 Ideal Loads Air, !- Ideal Loads Air Name
> > , !- Availability Schedule Name
> > Node Bloc1:Zone1 In, !- Zone Supply Air Node Name
> > , !- Zone Exhaust Air Node Name
> > 35, !- Heating Supply Air Temp {C}
> > 12, !- Cooling Supply Air Temp {C}
> > 0.01, !- Heating Supply Air Humidity Ratio {kg-H2O/kg-air}
> > 0.01, !- Cooling Supply Air Humidity Ratio {kg-H2O/kg-air}
> > NoLimit, !- Heating Limit
> > , !- Maximum Heating Air Flow Rate {m3/s}
> > , !- Maximum Sensible Heating Capacity
> > NoLimit, !- Cooling Limit
> > , !- Maximum Cooling Air Flow Rate {m3/s}
> > , !- Maximum Total Cooling Capacity
> > Bloc1:Zone1 Heating Availability Sch, !- Heating Availability Schedule
> > Bloc1:Zone1 Cooling Availability Sch, !- Cooling availability schedule
> > None, !- Dehumidification Control Type
> > , !- Cooling Sensible Heat Ratio
> > None, !- Humidification Control Type
> > , !- Design Specification Outdoor Air Object Name
> > , !- Outdoor Air Inlet Node Name
> > , !- Demand Controlled Ventilation Type
> > NoEconomizer, !- Outdoor Air Economizer Type
> > None, !- Heat Recovery Type
> > , !- Sensible Heat Recovery Effectiveness
> > ; !- Latent Heat Recovery Effectiveness
> >
> >
>