cove.tool can end over-designed systems and reduce initial and ongoing building expenditures.
cove.tool has sponsored this post.
With buildings comprising one of the primary sources of the world’s carbon emissions, accurate design of heating, ventilation and air conditioning (HVAC) systems can play a key role in minimizing these emissions. Over-designed systems not only cost more up front, but cost more to maintain and can be inefficient in their operation, generating unnecessary emissions.
More accurate estimation of thermal loads can help engineers design HVAC systems more precisely, improving efficiency. Using more sophisticated modeling techniques, designers can reduce uncertainty and avoid the need to add hefty cushions to design loads.
New Approach to Simulation
New software tools such as those from Atlanta-based cove.tool could significantly change decades-old practices of HVAC design and help reduce overdesign. “Traditionally, the goal was making sure you always had enough capacity,” said Patrick Pease, Mechanical Engineering Director at cove.tool. “You took whatever you calculated and added 30 percent or maybe even 40 percent. [With that approach], systems were oversized to guarantee they had enough capacity.”
To help designers right-size mechanical systems, the company’s load modeling tool can establish peak cooling and heating loads more accurately than traditional methods, says Pease. “Engineers rely a lot on rules of thumb. And with enough experience, they can apply those very effectively to get sizes that will work. But to get down to the absolute right size and still meet all your demands—that’s when these tools really come into play.”
Using techniques based on American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards, the software can help calculate space, system and plant loads in various scenarios throughout the year. Engineers, contractors and owners can analyze heat flow for room elements such as walls, windows, roofs, skylights, doors, lights, people, electrical equipment, non-electrical equipment, infiltration, floors and partitions.
The software has been tested in accordance with ASHRAE Standard 140, “Standard Method of Test for the Evaluation of Building Energy Analysis Computer Programs” and meets the requirements for simulation software set by ASHRAE Standard 90.1 and the ASHRAE Standard 183. The fundamental ASHRAE equations have essentially been digitized to enable ready analysis of multiple situations, according to Pease.
With rapid prototyping algorithms and automation of baseline inputs for domestic and international energy codes, designers can use the load modeling tool to perform real-time sizing on large, complex buildings with numerous HVAC conditions. “Say we have 500 rooms in a building. We want to do analyses not just once, but 500 times. These tools allow us to do that super quickly,” says Pease.
loadmodeling.tool is integrated with the wider cove.tool (cost vs. energy) platform and can be used throughout project stages, from early schematic design phases through construction. At the schematic and design development stage, it helps automate the evaluation of energy-saving concepts, such as the effects of daylighting, HVAC optimization strategies and high-performance glazing. At the construction drawing phase, a generated EnergyPlus model can help document compliance with ASHRAE Standard 90.1 or other green certification such as USGBC LEED, Green Globes and more.
Solar Loads
For load analysis, loadmodeling.tool can account for internal loads such as heat-emitting lights and operating equipment, as well as external loads such as solar gain entering through the windows and heat conduction though walls. Solar loads are some of the more complex loads to analyze, according to Pease.
“You need to calculate sun angles for the entire year and figure out when solar heat aligns with the heat from your lights or your equipment at the same time so you have peaks. That’s a very intense calculation that the tool does,” he says.
Location is also key to determining solar gain. “One of the data points that you have to input is location,” says Pease. “If you have a south-facing window in the northern hemisphere, you’ll get a lot of sun exposure, a lot of solar gain. That same window in the southern hemisphere will have much less gain.”
The software also allows designers to evaluate solar shading options. Users enter the depth and height of fins per window and analyze various combinations of shading, including iterative reviews of building performance with different solar shading strategies.
Neighborhood context can also be entered to simulate neighboring buildings or daylight obstructions, such as a high tree canopy. Glazing percentage can be used to evaluate solar shading to evaluate energy performance. The platform autogenerates a climate report with every project to identify various passive strategies based on building location. The report can also interpret climate diagrams and recommend various solar shading strategies.
Leveraging BIM Data
With loadmodeling.tool integrated into the wider cove.tool platform, designers can import and export data with building information modeling (BIM) and other formats. Using drawing.tool, users can import geometry directly from various CAD and modeling platforms. The drawing.tool helps define the rooms used for load models and enables translation of 3D models from various sources into analysis-ready geometry.
“By bringing all the geometry information into the tool, you save a ton of time,” says Pease. “If you have 500 rooms, nobody wants to redraw all the rooms and define them. The tool will bring that information in.” The tool can also be used to assign material properties and make minor edits to clean up BIM data, adds Pease.
After running load modeling, the entire detailed model can be exported in a wide range of formats including OpenStudio (.osm), EnergyPlus (.idf) and .gbXML. Models exported to .gbXML can be imported into a wide array of other software platforms including TRACE 3D and IES:VE.
Other Tools
In addition to loadmodeling.tool and drawing.tool, the cove.tool suite includes the analysis.tool, the quote.tool and the api.tool. Analysis.tool allows designers to select material components based on cost and performance data. Using machine learning, analysis.tool can scan multiple component options and help select the most cost-effective choice.
Quote.tool interacts with manufacturer data and enables communication amongst project team members via a chat feature. Quote.tool uses advanced analytics and a project profile to filter through hundreds of building designs and connect design teams and manufacturers.
Api.tool comprises a set of HTTP endpoints that help integrate custom applications with cove.tool. Api.tool is developed around the RESTful architecture which offers resource-based URLs and uses standard HTTP methods and status codes.
Because the cove.tool suite is cloud-based, complex models can be run without overtaxing local computing resources. With base models ranging from 10 megabytes to 500 or more megabytes, excluding load modeling results, the amount of data generated in energy modeling can be staggering, says Pease. “Load modeling can generate gigs worth of data. With a web-based solution, we can use cloud computing power to do all the data crunching.”
With the complexity of HVAC analysis, it is understandable that designers have relied heavily on rules of thumb, rather than conducting detailed analyses. But with increased attention being drawn to sustainability, energy efficiency and emissions reduction, the age-old approaches that produce overly conservative designs may not be acceptable on future projects. The cove.tool platform can provide a new suite of tools for conducting complex analyses in a manageable manner and right-sizing HVAC systems.
To learn more, visit cove.tool.
