An efficient ductwork system is a key element in an energy-efficient home. Heating, ventilation and air conditioning systems, also known as HVAC systems, use ductwork, hollow pipes and channels to distribute hot or cold air throughout a building. Errors in HVAC ductwork design can have expensive and even dangerous consequences. If you are drawing the ductwork of a complicated system or as part of a large construction project, you may consider using a computer-assisted design program or hire a professional. However, smaller projects may only require a simple design you can do yourself with pen and paper.
Take precise measurements. Your drawings don't have to look all that professional if they are for your personal use or for costing purposes, but they must be accurate. Write down and check all measurements before starting to draw.
Base your ductwork design on an existing set of drawings of your building. This will help you locate your ductwork more accurately within the building. The drawing can be a simple sketch on the back of an envelope or professional elevation and floor plan blueprints.
Use standard ductwork symbols to describe your drawings. Keep it simple. For example, a couple of parallel lines are all you need to describe a duct and an arrow will suffice to describe the direction of flow. A rectangle box made up of intermittent lines indicates the existence of a hidden sheet metal duct. Use abbreviations on your drawings to describe the type of ductwork you require, such as "FB" for bottom of duct fitting is flat or "FC" for a flexible unit connection.
Include relevant appliances and sensors. For instance, a circle with a "T" in the center stands for thermostat, while a square with a "PS" written inside stands for a pressure switch.
Title and date your drawing. Add any necessary comments that may be needed to understand.