Residential Hvac Drawing Flashcards
What are the two common types of construction drawings?
Pictorial type drawings
Orthographic type drawings
Define pictorial type drawings?
They are useful for representing visual ideas. It usually cannot be accomplished with just one pictorial view because of the details that may be hidden or not clearly shown when the object is viewed from one side.
What are orthographic type drawings?
Orthographic drawings can accurately scale and show all relevant sides of an object. These two dimensional drawings will accurately represent a three dimensional object.
How many views can be viewed with orthographic projection?
It can show all 6 different views.
What are object and hidden lines?
Object lines are used to outline shape of the object and hidden lines are used to show internal or hidden shapes within the object.
When starting an orthographic drawing, it is best to start with the view that has the most information on it or the view that contains the least amount of hidden lines.
True.
What are perspective pictorial drawings?
They give the most realistic representations of any objects. They are not used for technical information because the details are best understood in orthographic type drawings.
Describe one point perspective drawings.
They start with the closest face being drawn as an orthographic projection having vertical and horizontal lines parallel. A vanishing point is then chosen.
What is two point perspective drawings?
This uses two vanishing points. Only vertical lines run parallel to each other. It shows the top view better. Vanishing points must be greater than 90 degrees apart to reduce distortion.
What is three point perspective drawings?
It has 3 vanishing points which neither the vertical or horizontal line running parallel to each other.
Explain oblique type drawings?
They are similar to one point perspective drawings. An orthographic view of the closest face is drawn. The receding lines are parallel and are used to show the remaining views.
Two types of oblique pictorial drawings?
Cavalier- all projections are drawn at their true scale.
Cabinet- receding lines are shown at half their length.
What are isometric pictorial drawings?
Most common pictorial drawing. All lines on the same surface remain parallel and the same scale is used on all lines. Hidden lines are usually omitted from all forms of pictorial drawings.
In isometric drawings circles and arcs are shown as ellipses or part of an ellipse on vertical and horizontal surfaces.
True
