Accurate - Compliant - Professional
Fire Alarm Design Phases Developed Internally at Peace of Mind Fire
Over a period of 15 years and continuing, my team and I have developed a series of phases that allows us
to produce accurate fire alarm drawings eliminating unfavorable mistakes. We continue to improve this process as new safety measures are utilized and the ever-changing fire environments.
Fire Alarm Design Phase-I
Preliminary Planning
A thorough review and analysis of architectural and MEP plans must be conducted during phase I. It is critical to initiate any RFI (Request For Information) to clarify requirements that may not have been addressed during the initial planning stages.
During this phase we verify:
-
Square footage.
-
The number of floors.
-
Specific hazard areas.
-
Safety functions & additional requirements such as elevator recall, fire suppression, HVAC shutdown & other critical control actuation.
-
Occupancy Use Groups & Occupant Load Factors.
-
Design intent & narrative.
-
State & Local Jurisdictional requirements & Amendments.
Fire Alarm Design Phase-II
Applicable Code Requirements,
Risk Assessment & Proper Fire Alarm System Selection
Typically, fire alarm systems are designed based on code minimum requirements. This approach is common to reduce the installation cost of a fire alarm system. However, a prudent designer as part of the risk analysis will examine inherent fire risks based on occupancy type, building location & statistical data.
Nicet Certifed levels III & IV with have a thorough understanding of the code
sets which include and not limited to:
-
NFPA-72 National Fire Alarm and Signaling Code
-
NFPA-70 Nation Electrical Code
-
NFPA-101 Life Safety Code
-
International Building (IBC)
-
International Fire Code (IFC)
Find out more about Code Minimum &
Why It's Not Always The Best Approach.
Fire Alarm Design Phase-III-A
Communicating with other trade contractors
After carefully selecting the type of fire alarm system to be installed, and the extent of protection, the next phase is to speak with other trade contractors. Often we will find the building owner decides to change the mechanical plan from generic rooftop units over 2000 CFM to using mini-splits because the HVAC contractor is capable of performing a design-build that can be more cost-effective than traditional HVAC engineering applications. This is important because any HVAC system that generates more than 2000 CFM is required to be shut down to reduce the spread of toxic smoke. In order to perform this operation, we have three trades that must be involved. The HVAC contractor must install a duct detector as required per NFPA-90A. The shutdown emergency stop circuit requires the electrician to pull a control circuit from the rooftop HVAC unit down to the fire alarm control relay installed, wired, and programmed by the fire alarm contractor. This would ultimately affect the design. We constantly keep in touch with trade contractors to verify whether plans have or have not changed so we can take appropriate action quickly.
Fire Alarm Design Phase-III-B
Buildings Undergo Multiple Revisions - We Are Prepared
Buildings with elevator systems undergoing renovations are required to be recalled away from a fire floor. I won’t discuss in detail the interconnecting methods and requirements of elevator system controllers to fire alarm systems due to the complexities involved. What is critical is verifying the equipment has not changed. Too often the elevator contractor is last to submit their plans or perhaps the traveler cable is combustible, and this isn’t discovered until later in the process which then pushes a requirement to place a sprinkler head(s) in the shaft. This then drives the fire alarm requirement to have a heat detector within 2’ of the sprinkler head and we must initiate a shunt-trip prior to activation of the sprinkler system. This ensures power to the elevator is shut down and electrical components do not become energized causing electrocution to the occupants or erratic behavior of the elevator.
Fire Alarm Design Phase-IV
Performing The Design
The Photo Above Is From A Live Project
Notice Magenta Text. Our Designers Added This
Missing Information To Comply With Requirements
The only time a design can commence is after the first three phases are complete. During the design, we carefully select system manufacture based on availability, cost, and possible future expansion while determining a cost-benefit ratio.
Designs must follow the minimum documentation standards from both the IBC and the NFPA-72. Per the IBC Section 907.1.2 Fire Alarm Shop Drawings Shall include, but not be limited to, the following:
1. A floor plan that indicates the use of all rooms.
2. Locations of alarm-initiating devices.
3. Locations of alarm notification appliances, including candela ratings for visible alarm notification appliances.
4. Location of fire alarm control unit, transponders, and notification power supplies.
5. Annunciators.
6. Power connection.
7. Battery calculations.
8. Conductor type and sizes.
9. Voltage drop calculations.
10. Manufacturers’ data sheets indicating model numbers and listing information for equipment, devices, and materials.
11. Details of ceiling height and construction.
12. The interface of fire safety control functions.
13. Classification of the supervising station.
Fire Alarm Design Phase-IV
Performing The Design (Continued)
Next, we set up the project file in AutoCAD and begin to layout devices in accordance with the NFPA-72. The symbols we place in our drawings are directly from the NFPA-170 and which is the standard for fire safety and emergency symbols. Some design companies tend to generate their own symbols and we have found this creates confusion between the fire marshal and field installers. We always adhere to standards again reducing delays during the submittal process.
There are very specific rules that must be followed pursuant to the NFPA-72 when laying out a fire alarm system. The designer must be aware of all the requirements that include different applications while also bearing in mind building aesthetics and effectiveness of device placement. A common error we find is notification appliances for ADA sleeping rooms have an incorrect candela setting. A unit classified as ADA will require a visible appliance (strobe) in addition to a horn or low-frequency sounder.
The Photo Above Is From A Live Project
Detailed Key Notes Eliminate Confusion.
Fire Alarm Design Phase-IV
Performing The Design - Testing Calculations
Finally, after all the devices are placed in the plan, we perform a pre-analysis of circuit pathways to maximize the effectiveness of the circuit while reducing resistance. There could be alternate paths for the wire to travel, limiting devices on the circuit or supplying more power and circuits, as needed, for worst-case scenarios.
After the pathways are determined devices are numbered and calculations are performed. Voltage drop calculations are required to ensure the devices will operate within their voltage parameters considering ambient conditions that can also affect wire resistance.
Failure To Properly Follow Guidelines Can Be Catastrophic
To Learn More
The Photo Above Is From A Live Project
We Are Thoroughly Testing The Voltage Drop
Fire Alarm Design Phase-IV
Performing The Design - Calculations - Continued
The next stage is performing a battery calculation. The fire alarm system must be able to operate for 24 hours on standby and 5 min in alarm. For mass notification, the alarm at max load requirement is 15 min. The batteries shall be sized so that by the end of the 24-hour standby period, should the fire alarm activate, the batteries must be able to sustain the system for 5 minutes at maximum load before the system malfunctions from total power loss.
Once calculations are complete, we tag the circuits. This instructs installers to use a wiring legend we place on every sheet. This information is crucial for the installer. It ensures they will pull the correct wire to the correct devices.
The Photo Above Is From A Live Project
A Wire & Device Legend Allows Installers to Communicate
Fire Alarm Design Phase-IV
Performing The Design - Riser Diagram
Next, we generate a riser diagram. This is the overall snapshot of a point-to-point, floor-by-floor, view of how all the devices are connected to the system. This separates all the circuit pathways making it more effective to analyze the circuits in detail.
Once the riser is complete, we move on to the details sheet. Besides the calculations, the most amount of time is spent performing details. We provide wiring schematics of devices and the panel(s). Each is unique to the project based on the system type and devices required for the fire alarm system.
The Photo Above Is From A Live Project
This Diagram Must Be Free of Error
The details sheet allows field installers to review the appropriate wiring schematics for each device specified in the fire alarm drawing.
-
Elevation details are also provided to ensure mounting heights and locations are observed.
The Photo Above Is From A Live Project.
Wiring & Elevation Details Increase Productivity
Fire Alarm Design Phase-IV
Details
Fire Alarm Design Phase-IV
Performing The Design - Completing The Cover Sheet
After we finish the details, we then go to the cover sheet to apply general notes and generate a bill of material. We then begin filling in the rest of the cover sheet with specifications performed during the code analysis.
-
We perform a final review of the drawing set before creating a submittal
-
package.
-
Included are the applicable model codes. These codes vary based on project location and local municipal requirements.
-
The input/output matrix is built. This is a vital piece of the design as it brings attention to the field programmers on how the sequence of operations are tied together.
The Photo Above Is From A Live Project
The Cover Sheet Covers The Entire Scope
Fire Alarm Design Phase-IV
Performing The Design - The Submittal -
Once the design drawing has been completed and checked we create the submittal package. This process involves plotting the drawing set to a PDF where parties involved will be able to view and print the plans for field installation.
In order to secure a permit, data sheets are required. Commonly referred to as cut sheets, each provides detail of the component being used.
For us, just assembling all the data sheets isn't enough. We meticulously review the part number and annotate the document. Manufactures to save on resources will have a single datasheet that covers a range of device variants. It's crucial the AHJ and the company ordering the material can refer back to the data sheets to confirm the correct model number.
The Photo Above Is A Data Sheet
With Our Highlight
Fire Alarm Design Phase-V
Design After Support & AsBuilts
After I have signed off on the completed design and submittal, I remain on standby and check in with my clients to ensure the project is going smoothly. Furthermore, I maintain open lines of communication with trade contractors to stay ahead of changes. I find this minor step can easily reduce the cost of change orders by over 40%. I am available to be called directly to answer any questions the field installers may have on the design. This may also be in person or virtual site visits.
Once the project is complete, I will have kept a detailed list of changes that may have taken place. This will be reflected in the AsBuilt plan. This is the final drawing set that has been updated hence the name As Built. Modifications after the CO is signed off on require changes to the design that will be under permit. This ensures all the NFPA-72 documents are updated.
Summary
There is a substantial amount of experience and knowledge that goes into fire alarm design and we covered only about 15% of the overall scope. If you took the time to read through the information I provided, you have a very clear understanding of how complex these silent watchmen truly are. You’ve learned not all designers are equal. Price shouldn’t be a factor when selecting a fire alarm designer. I thank you for taking the time to personally review the site and my company.
You are welcome to reach out to me any time to review your project needs.
Thank you,
Joseph Montuori, CEO, SET
