The new version of Trimble Nova 16.3 helps HVAC engineers and installers to calculate calorimetry in accordance with the current SIA 384/2:2020 standard, also using intelligent online technologies that offer numerous benefits to users.
Trimble Nova 16.3 offers thermal load calculations in accordance with the new Swiss standard SIA 384/2:2020. In addition, Trimble Nova also supports the current national annexes for Germany (DIN EN 12831) and Austria (H 7500-1). Calculating heat loss is one of the main tasks of HVAC engineers and installers. In both old and new buildings, it is used to determine the normative heating requirements per room, and to size heating surfaces, distribution networks and heat production to ensure reliable, economical operation.
What's new in SIA 384/2:2020?
SIA 384/2:2020 "Heating systems in buildings - Power requirements" defines easy-to-use methods valid for Switzerland for calculating standardized static heat loads under standard conditions. The main changes from the previous version of SN EN 12831:2003 are as follows:
When calculating the thermal load, heat input can be taken into account.
For room heights of 4 metres or more, the ambient temperature is corrected for each building element.
The influence of groundwater has been taken into account since SIA 380/1.
For the determination of the estimated ambient temperature of non-actively heated rooms, the method of SN EN 12831-1:2017 has been adopted.
The equivalent thermal transmittance for buried wall calculations is calculated using the simplified procedure in SN EN 12831-1:2017.
For ventilation losses, only the minimum air exchange rate is now taken into account. For minimum air exchange rates, different values can be used (depending on circumstances).
Heat losses through transmission to adjoining rooms that are not heated all year round (e.g. terraced vacation homes) and are connected to different heat production systems are calculated according to paragraph 2.2.3 (unheated rooms).
Updated consideration of building inertia
Terms, symbols and indices have been harmonized with SIA 380/1.
Calculating thermal loads with Trimble Nova 16.3
Trimble Nova's fully-integrated calculation function enables easy dimensioning of thermal loads in accordance with the current SIA 384/2:2020 standard. The thermal surface model interpreted from the building mock-up, either imported via IFC, created manually or from existing 2D plans, serves as the basis for the calculation. This model can then be used to dimension radiators, underfloor heating and cooling loads. Thanks to predefined target values, the user obtains an initial calculation result immediately after opening the heat loss calculation module, which can then be refined and customized through individual entries. Formulas and designations in the interface are strictly identical to the standard, making use and input more transparent. Intelligent help and error analysis also help users who are not yet fully familiar with the current standard. A digital traffic light indicating the current status of the calculation enables users to orientate themselves as to whether the data entered for the calculation is correct and complete.
Thermal load calculation in detail
Before performing the thermal load calculation, the user can define whether it should be performed according to the national appendix (SIA 384/2) for Switzerland, Germany (DIN EN 12831) or Austria (H 7500-1). The Swiss national annex (SIA 384/2) is pre-set for users in Switzerland. In addition to heated and unheated rooms, "non-actively heated rooms" are also taken into account. These are buffer spaces which, unlike unheated spaces, are not located outside but inside the building's thermal envelope, and are neither actively heated nor cooled. Appropriate distinction helps to reduce the surface area of the building's thermal envelope or avoid thermal bridges. For rooms with undefined typology, the temperature can be determined individually. If a ventilation concept is required for the whole building, it can be specified at the overall building level or individually for each room, and can be quickly adapted via a grid view. The ventilation concept is not the only element relevant to the minimum air change rate: it is also necessary to specify whether a room has a relationship with the outside, and whether it is a room with air inlets. Because of the importance of heat loss due to ventilation, the user also has the option of entering all values manually. For heated rooms, an additional heat input can be entered. At building level, users can define whether or not high-ceilinged rooms should be included in the calculation. Linear thermal bridges can be defined on walls, doors and windows, drawn in CAD or entered in tabular form.
Online service technology offers advantages
Trimble Nova 16.3 uses the latest cloud services technologies to increase computing power, delivering very fast results. Even complex, large-scale projects can be calculated in seconds, without users needing to guarantee the corresponding computing capacity locally (via their machine resources). To do this, Trimble Nova transmits all relevant building data, such as surfaces, volumes, U-values, etc. to the cloud for calculation. The results returned to Trimble Nova are saved locally and can be evaluated in the form of reports. Building data is compressed so that the volume of data transferred is as low as possible, and even large projects can be transferred quickly. The latest security standards guarantee secure data transfer. The use of cloud technologies to create a computing platform also simplifies software development and maintenance. With the exception of changes to the programming interface (API), any software adaptations or error corrections can be made online, without the need to install an update.
For more information on Trimble Nova and the new version 16.3, click here.
