In this lesson, we cover: How to properly calculate standard 62 in Trace 700. We do not cover everything on the max z ratio, so if you wish to fully understand the max z ratio, please read this.

At this point, we have looked at most of the basic inputs in TRACE 700, as well as some of the more complex ones. However, as a user of TRACE 700, you will find that you spend most of your time doing smaller but more complicated tasks. By understanding some of the features TRACE 700 can do, and understanding them fully, you can save yourself some big headaches in the future. For instance, let’s start with entering Ashrae Standard 62. We can enter that either by going to create templates, or to create rooms. In this case we’ll select create templates. We select create templates, and go to the air flows tab. Standard 62 can be enabled by selecting yes to apply Ashrae Standard 62 2004 or 2007. When we select yes, there’s a couple changes made to the tab. It's not clearly evident, but the types listed here actually change. Now, instead of having a heating and cooling CFM, we have a people based, and an area based. The schedules stay the same. The other fields that are enabled are the cooling Ez, the heating Ez, and the ER value. Typically we’ll want to select values from the drop down menu, such as ceiling cooling supply, and ceiling return. This gives a 100% effectiveness factor meaning that in cooling mode, 100% of the ventilation air is counted as ventilation. If in the heating Ez we select a ceiling supply with a delta t greater than 15, and a ceiling return, we end up with an effectiveness factor of 80%. Since we're supplying and returning air at the ceiling level, and hot air is more buoyant than cold air, we assume that a portion of this air is short circuited, 20 % in this case. Finally, we have the ER value. Typically, you want to select this based on the system type. Finally, there’s a DCV minimum outdoor air intake. Typically, you can leave this field blank. However, if you're doing demand control ventilation, and you have a minimum amount of outdoor air selected, we can say that we're only allowing it to set back to 30% of the design outdoor air flow. In this case, that’s equal to 30% of the people based air flow, as well as the area based air flow. At this point, it appears that we have selected all of our parameters for Ashrae Standard 62. However, if you think that, you're probably going to get slapped because this defines the amount of air flow. However, for those of you that know a thing or two about Ashrae Standard 62, it also changes the way the system ventilation is calculated. In order to make that change in TRACE 700, we have to apply these changes, close out of create templates, and go to create systems. When we're in create systems, on the first tab we click the advance button. At the bottom of the advance button, there’s a field called the system ventilation flag. It defaults to the sum of the room outdoor air requirements, which adds up all the CFM’s defined under ventilation for every room on that system, and that’s the total system ventilation. However, Ashrae Standard 62 takes into account the fact that a system can supply only one given percent of outdoor air to all the rooms on a given set of duct work. As a result, we have to select the Ashrae Standard 62 2004-2007, and we have the option to select it with ventilation reset.