Re: How to set night cooling strategy
Posted: Sun Aug 09, 2009 1:24 pm
Can you tell us anything about the building?
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How to set night cooling strategy
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Re: How to set night cooling strategy
Posted: Mon Aug 10, 2009 10:53 pm
Silvestre, how you model night cooling depends on the building. If it is naturally ventilated, yes, your method would work; if it is mechanically ventilated, then that wouldn't work. You are correct regarding time profiles though, they need to be created, but you can't just ventilate from 19:00-07:00 if it is mechanically ventilated, that would be extremely wasteful!
Re: How to set night cooling strategy
Posted: Wed Aug 12, 2009 12:16 pm
Sure, but you really need to give more details. What kind of mechanical ventilation, also 'comfort cooling' can mean so many things. You've asked for help setting your night ventilation: what is your night ventilation strategy? What logic do you wish to use. I can help you use the software, but the software is just the interface; what is your desired design that you are trying to simulate?
Re: How to set night cooling strategy
Posted: Wed Aug 12, 2009 3:24 pm
Ok.
To get your free cooling with mechanical ventilation, setup auxiliary ventilation in your templates (in the air exchanges tab), with an airflow rate that you will specify, a variation profile that you will need to create in Apache Profiles and use formulas to make sure it turns on/off when you want it, and under adjacent condition select "external air + offset temperature", with the "offset temperature" being the temperature increase due to the supply fan.
When you're creating the formula to control when night ventilation activates, you'll need to use an annual profile to ensure it only goes on in summer, and you should probably also make it a function of room temperature and outside air temperature, for instance make sure it is off when the outside air temperature + offset temperature is higher than room temperature. You also don't want the thing to be on all night as it defeats its purpose of saving energy, and so there are times of day when the air is much cooler and night ventilation is more effective. I mean, these are all things you will need to setup in your profiles, and you'll need to determine what kind of night ventilation strategy you want to employ.
To get your free cooling with mechanical ventilation, setup auxiliary ventilation in your templates (in the air exchanges tab), with an airflow rate that you will specify, a variation profile that you will need to create in Apache Profiles and use formulas to make sure it turns on/off when you want it, and under adjacent condition select "external air + offset temperature", with the "offset temperature" being the temperature increase due to the supply fan.
When you're creating the formula to control when night ventilation activates, you'll need to use an annual profile to ensure it only goes on in summer, and you should probably also make it a function of room temperature and outside air temperature, for instance make sure it is off when the outside air temperature + offset temperature is higher than room temperature. You also don't want the thing to be on all night as it defeats its purpose of saving energy, and so there are times of day when the air is much cooler and night ventilation is more effective. I mean, these are all things you will need to setup in your profiles, and you'll need to determine what kind of night ventilation strategy you want to employ.