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A complete guide to HVAC drawings and blueprints


HVAC Drawings


Content


Reading HVAC Drawings


The mechanical drawings consist of the HVAC (heating, ventilating, and air-conditioning) systems. The details of a complete HVAC system are provided in HVAC plans. This is a very important part of HVAC training. Let’s see the details provided at different locations of drawings. Recall that the general notes are provided on the first page, along with legends and symbols. It consists of instructions followed during the complete installation of duct, pipes, and equipment. It also provides details of the owner’s requirement or renovation guidelines.




Recall that every drawing has its symbols with descriptions that are provided in the legends. HVAC systems are denoted using symbols for various uses such as equipment, diffusers, piping sizes, and duct layouts.


Legends contain abbreviations with symbols used for equipment, piping, ducts, and other features shown in a plan view. Floor plans do not include notes or details for all those symbols used on the plan. The best practice is to refer to legends before moving on to the plans.


The drawings consist of HVAC ductwork and diffusers, but the names are provided in abbreviations. As HVAC systems carry water, air, electrical lines, or a combination of these, names or text for all these items will be mixed-up with the plan and difficult to read.


The abbreviations or short names are defined on the first page of HVAC drawings. The HVAC plans are schematic, using symbols and abbreviations to denote the various parts such as equipment, ducts, control devices, diffusers, and piping.


For example, chilled water and hot water supply lines are denoted as:

  • CWS - Chilled Water Supply

  • CWR - Chilled Water Return

  • HWS - Hot Water Supply

  • HWR - Hot Water Return

Wall lines are often drawn lighter and thinner than the HVAC system lines to make the system particulars stand out clearly. In some instances, the ductwork might be shaded for easier identification. Special kind of line types is used to indicate fire-rated wall or equipment sections.


As seen in the image, the HVAC duct lines are darker than the wall lines. The wall lines and the area names are used as a reference to locate the diffuser position or HVAC duct routing. The diffusers have a name or code on them, so it is referred to in the schedules for its details.


Recall that the schedules include manufacture, type, model, size, and details of the equipment. Schedules help to know details of the required equipment or item denoted on the mechanical plans. HVAC duct drawings include schedules for equipment such as AHU, diffuser, fan, heater, and chillers.


The HVAC drawings include equipment and diffusers, which are provided in symbols on the drawings. This equipment needs to be described as it is used to estimate, order, and install at the site. The schedules fulfill these requirements.


HVAC plans are generally drawn at the same scale as the floor plans. The scale helps to measure the size, length, and distance of the plans. The most common scale is 1⁄4" = 1'-0" (1:50 metric) for residential and small commercial projects, and 1⁄8" = 1'-0" (1:100 metric) for large commercial projects.


The scale at which the HVAC plans are drawn is provided either adjacent to or directly below the drawing title. Sometimes designers might enlarge the detailed and related equipment drawings with their respective scales shown below the drawing.


HVAC drawings include details for the AC system, refrigerant pipe connections, and duct layouts. General notes, abbreviations, legends, and symbols, are found on the first page of the mechanical drawings. Schedules help to find the details of the equipment or fixtures provided with reference names on the plans.





 

HVAC Plans

In this module, we will learn about reading HVAC plans and their usage. Skip to Quiz!


Engineers, architects, and mechanical contractors are the primary designers of HVAC plans. This is one of the most important parts of HVAC training. However, interior designers decide how the HVAC duct, equipment, and pipe routing are installed. It is also used to check how it will affect the interiors of a building.


A designer needs to coordinate the reflected ceiling plan to provide the correct location of registers, grilles, thermostats, and appliances with the other construction trades. HVAC plans include multiple drawings which describe the duct, piping, and riser layouts in detail.




HVAC duct layout consists of duct routing inside the ceiling. As seen in the picture, the duct layout is installed while referring to the drawings provided at installation time. The ceiling is installed once all the ductwork is done.


The details about duct type, diffuser details, installation methods, or any information necessary to read the drawing are provided in a section of the drawing called plan notes. For example, the notes might specify duct type and insulation as 1-inch (25 mm) fiberboard or nitrile rubber.


In a water system, copper piping or other materials might be called out in notes as to their diameter and grade to be used during installation. Consider the first point in the notes “Field verify thermostat location with the owner representative.” The thermostat location is provided in the plan but needs to verify the location with the owner representative.


Section drawings provide more information on how a building, interior space, or equipment is installed. It may be divided into one or more multiple views through different angles. Section drawings take such an imaginary slice through an object or building.


Section drawings of HVAC plans provide details of equipment provided in-between the floors, ceilings, spaces, height of the walls, and equipment locations above one another. Two or more sections are often provided at 90 degrees to one another to give additional information.


The commercial buildings consist of multiple similar areas like apartments and hotel rooms. The multiple area floor plans are represented on drawings by a code or reference name on the floor plan. In HVAC drawings, the AC details are found on these drawings.


It is helpful to identify the correct location of pipes, wires, and connection points from the main lines. As seen in the image, the unit plan provides the location of AC units in the floor plan of the respective area. Let us summarize how to read the plan while utilizing all the sources.


The checklist for referring HVAC plans are:

  • Check for the title of the drawing, note its scale, and reference to the orientation or directions,

  • Check for symbols, abbreviations, and legends,

  • Readout general notes and respective plan notes for more details,

  • Refer to schedules or specifications before referring any equipment on the plans,

  • Check thermostat locations in all the floor plans to coordinate electrical, furniture, and wall layout,

  • Check the drawings with the reflected ceiling plan(RCP) and other trades drawings to find proper locations and routings,

  • Check the drawings of air-conditioning equipment and plant room drawings for the line connections and relevant machines,

  • Check out for the access panels and connections from the main distribution board to access the power supply for equipment,

  • Check the call out for exhaust vents (bathroom and kitchen equipment) to the exterior or elevation plans,

  • Check the details, sections, riser diagrams, and enlarged plans for more details, and

  • Finally, during maintenance, refer to the final set of drawings As-Built drawings.


The HVAC drawings provide details for the AC system, refrigerant pipe connections, chiller, and duct layouts. The HVAC plans include plan notes to describe the installation details and fixture types. The commercial buildings’ details of AC layout are available on the enlarged unit plan of respective area.





 

Question #1: Where are general notes provided on HVAC plans?

  1. Last page

  2. Not provided

  3. On plans

  4. First page

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Answer: First page

The general notes are provided on the first page of HVAC plans or any plans.


Question #2: Where does the description of HVAC symbols for various uses such as equipment, diffusers, piping sizes, and duct layouts is provided on the plans?

  1. Legends

  2. General notes

  3. Abbreviations table

  4. Table

Scroll down for the answer...














Answer: Legends

HVAC systems are denoted using symbols for various uses such as equipment, diffusers, piping sizes, and duct layouts, and its description is provided in legends.


Question #3: In HVAC drawings, symbols are provided with short forms or letters, and these details are found in:

  1. Legends

  2. Floor plan

  3. Plan notes

  4. Abbreviations table

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Answer: Abbreviations table

In HVAC drawings, symbols are provided with short forms or letters, and these details are found in the abbreviations table.


Question #4: In HVAC drawings, equipment details such as AHU, diffuser, fan, heater, and chillers are provided in:

  1. Symbols

  2. General notes

  3. Schedules

  4. Tables

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Answer: Schedules

In HVAC drawings, equipment details such as AHU, diffuser, fan, heater, and chillers are provided in schedules.


Question #5: _____ helps to measure the size, length, and distance of the plans.

  1. Sheet number

  2. Title block

  3. Details

  4. Scale

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Answer: Scale

The scale helps to measure the size, length, and distance of the plans.


Question #6: The notes available on the plans which describe the installation details, method, type of diffuser, or any equipment are known as:

  1. Office notes

  2. Plan notes

  3. General notes

  4. Copy notes

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Answer: Plan notes

The notes available on the plans describing the installation details, method, type of diffuser, or any equipment are known as plan notes.


Question #7: Which drawings provide more information on equipment installed in-between the floors?

  1. Equipment plan

  2. Elevation drawings

  3. MEP drawings

  4. Section drawings

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Answer: Section drawings

Section drawings of HVAC plans provide details of equipment provided in-between the floors, ceilings, spaces, height of the walls, and equipment locations above one another.


Question #8: The steps for referring HVAC plans include: (Select all that apply)

  1. Check for the title of the drawing

  2. Refer architectural notes on HVAC plan

  3. Plan dates need not be referred

  4. Check for symbols, abbreviations, and legends

Scroll down for the answer...















Answer: Check for the title of the drawing

Check for symbols, abbreviations, and legends

The checklist for referring HVAC plans are:

  • Check for the title of the drawing, note its scale, and reference to the orientation or directions,

  • Check for symbols, abbreviations, and legends, and

  • Readout general notes and respective plan notes for more details.


Question #9: The steps for referring HVAC plans include: (Select all that apply)

  1. Check for beam layout plan

  2. Check the details, sections, riser diagrams, and enlarged plans for more details

  3. During maintenance, refer to the final set of drawings As-Built drawings

  4. Check for the landscape plan and its details

Scroll down for the answer...















Answer: Check the details, sections, riser diagrams, and enlarged plans for more details

During maintenance, refer to the final set of drawings As-Built drawings

The checklist for referring HVAC plans:

  • Check the call out for exhaust vents (bathroom and kitchen equipment) to the exterior or elevation plans,

  • Check the details, sections, riser diagrams, and enlarged plans for more details,

Finally, during maintenance, refer to the final set of drawings As-Built drawings.

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