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Excel Modules: "HVAC Engineering Book"

The Modules are an unprecedented alternative to the expensive HVAC design software tools. Linked together in a computational system, the modules calculate ALL of the design steps using the robust, simple and user-friendly MS Excel platform!

Traditionally, HVAC engineering practices have included notebooks filing all calculation worksheets to support the HVAC drawings and specifications. The modules serve the same purpose: they carry out the calculations and keep track of inputs and outputs in electronic format. Following the tradition, the suite of Excel modules presented here is collectively called HVAC Engineering Book©. The modules are coded based on latest ASHRAE standards and methods and available in both Inch-Pound (IP) and Metric (SI) units.

The interlinked modules will drastically reduce your design time and errors during entering and tuning the input data. For example, if you change a window type, the modules will automatically resize the equipment, ducts, and piping. The modules are organized in interlinked worksheets (called "tabs") placed in chronological order of the design process. Some of the tabs require data input and others return the calculation results. You simply enter the input data and read the calculation results. You do not need to remember either the formulae or the sequence of the calculations. The modules will do the job for you! Check out the modules’ screens below to see how limited the input data is (the grid cells designated for the data input are white, the cells with the calculation results are grey).

The COMFORT module predicts the feeling of comfort in a space at various radiant and indoor air conditions. The calculations are based on Standard 52-2004 “Thermal Environmental Conditions for Human Occupancy.”

The DESIGN LOADS module performs the following steps of HVAC design:

• TheClimate tab summarizes the design climatic data
• TheEnvelope tab calculates U-values of the envelope elements
• TheZoning tab allows to group the building spaces into comfort zones
• TheSystem Configuration tab allows to configure the air-conditioning systems of the building
• TheSpace Ventilation tab calculates the space ventilation airflow rate requirements as per ASHRAE Standard 62.1-2007
• TheSpace Heat Loss tab calculates the space heat losses
• The Cooling Load tabs calculate the cooling loads from walls, windows, and other heat sources and summarize thespace cooling load breakdowns
• TheFans,Cooling Coil, andHeating Coil tabs size: supply and return air fans; cooling and heating coils; and humidifiers of the systems
• TheReheat Coils and Space Heating Unit tabs summarize the zone reheat and perimeter heating unit loads
• TheBuilding Heating Loads tab computes the building heating load breakdown
• TheReports tab converts the tabs' calculations into printable reports.

The AIRFLOW module includes two tabs:

• TheDiffusers tab calculates the air jet throws from air diffusers and registers required to provide even air temperature and velocity distribution in the rooms
• TheDucts tab sizes duct systems of different shape and material.

The WATERFLOW module includes three tabs:

• ThePipe Load Calculator tab distributes thermal loads and water flow rates amongst the sections of direct and reverse return fluid piping systems
• ThePiping tab sizes the piping system for a selected pipe material and fluid temperature. The module provides the pressure losses and water contents in the system.
• The Expansion Tank tab sizes diaphragm-type expansion tanks.

The modules were validated against the examples given in the source ASHRAE handbooks and the simulations performed by the software tool HAP-4.31 (Carrier Inc.) for a sample project. The validation testified that the accurately calculate constant and variable air volume air-conditioning systems with up to 50 individual comfort zones and 150 spaces.