By Colin Goode, Fujitsu’s Product and Specification Manager
While we are always happy to give technical assistance to anyone who needs it, the fact is that the best person to make the necessary calculations is the one who has surveyed the building and knows the client’s requirements; in other words the system designer or installer.
Rules of Thumb
Accurately estimating the cooling /heating loads for every application is a fundamental design requirement of every heating and cooling project. This is vital to prevent over or under sizing of equipment and is something that should be done by the contractor or the person responsible for the overall system design.
In other words, there is no point in installing an Airstage VRII when a JIIS will do the job more efficiently, or installing a split where a VRF is needed. This will ultimately lead to customer disappointment.
Calculating the loads
There are many load estimating software packages available. Some relatively simple free calculators can be found on the internet but any self-respecting contractor or designer should purchase something more sophisticated, such as AC Calc by Click Software, which uses industry recognised methods to model old and new building types. This software is more than adequate for most small to medium sized projects.
We now have the Fujitsu Design Simulator, which allows you to set up the whole system on a computer to check that everything works with everything else.
All aspects from selecting controls and optional parts to designing piping and wiring systems is made easier by the program’s built-in features.
Once the project is designed, the export functions can be used to output materials lists, product specifications, refrigerant calculations and more. It can also export to Word or Excel and group relevant CAD data for your project.
Ask a consulting engineer for help
More sophisticated heat load calculations are necessary for larger buildings to meet new building regulations so the consulting engineer will liaise with manufacturers to produce a system design and specification that meets your client’s needs and current requirements.