Duct Detector Testing

[Eaglesionu]

Hi All,

I have some questions related to how Duct Detector testing is being performed. I my experience the Fire Alarm company is the only company performing testing of the duct detector. I have rarely seen anyone use smoke for testing, instead a magnet test or remote test switch is more often used. I'm aware that the magnet/RTS method is not considered a functional test.

I've seen many fire alarm companies recently put the HVAC testing off on to the HVAC company unless they are on-site during the fire alarm test. My question is, what are your experiences w/ detector testing. Fire Alarm Guys aren't HVAC technciains and HVAC technicains arent Fire Alarm guys...

I feel that this is one of those gray areas in the code where the Fire Alarm company is expected to be an expert on systems that arent direclty related to thier license. Those gray areas are HVAC systems, Ansul Systems, Sprinkler Systems, Elevator systems to name a few.

Thank you in advance for any info.

 

[mtnelect]

Go to the California Energy Commission website www.energy.ca.gov under the Title 24. Look under HERS (Home Energy Rating Systems) providers. Companies like: www.calcerts.com, www.cheers.org they are providers that train and supervise HERS raters, for residential and commercial buildings.

 

[ron]

The duct detector must be tested with smoke per NFPA 72. A fire alarm company's testing is not complete with shutting down the units, along with all other controlled sequences like releasing magnetic door locks or elevator recall.

 

[gadfly56]

The duct detector must be tested with smoke per NFPA 72. A fire alarm company's testing is not complete with shutting down the units, along with all other controlled sequences like releasing magnetic door locks or elevator recall.

NFPA 72 accepts whatever method is approved by the duct detector's UL listing. So, magnets are fine for System Sensor DH100 series, and remote test switches for others. I agree that you really need to put smoke in the chamber to get a true functional test, but I don't make the rules.

 

[ron]

NFPA 72 accepts whatever method is approved by the duct detector's UL listing. So, magnets are fine for System Sensor DH100 series, and remote test switches for others. I agree that you really need to put smoke in the chamber to get a true functional test, but I don't make the rules.

From NFPA 72-2019 Table 14.4.3.2 for a duct type smoke detector:
In addition to the testing required in Table 14.4.3.2(g)(1) and Table 14.4.3.2(h), test duct smoke detectors that use sampling tubes to ensure that they will properly sample the airstream in the duct using a method acceptable to the manufacturer or in accordance with their published instructions.

How can a magnet or remote test switch ensure that the detector will properly sample the air stream?

 

[Eaglesionu]

I appreciate everyone's response. However, i think i may need to clarify what specifically i'm asking.

In your experience, have you seen duct detector testing performed maily by the Fire Alarm inspection company?

Have you seen any fire alarm inspection company's eliminate duct detector testing unless an HVAC technician is present?

 

[ron]

I appreciate everyone's response. However, i think i may need to clarify what specifically i'm asking.

In your experience, have you seen duct detector testing performed maily by the Fire Alarm inspection company?

Have you seen any fire alarm inspection company's eliminate duct detector testing unless an HVAC technician is present?

I've seen that.

I've also seen a fire alarm testing company take exclusion to other things like elevator recall and air sampling smoke detectors. The owner then needs to get those inspections by another firm (usually only happens once, then the company is replaced)

 

[gadfly56]

From NFPA 72-2019 Table 14.4.3.2 for a duct type smoke detector:
In addition to the testing required in Table 14.4.3.2(g)(1) and Table 14.4.3.2(h), test duct smoke detectors that use sampling tubes to ensure that they will properly sample the airstream in the duct using a method acceptable to the manufacturer or in accordance with their published instructions.

How can a magnet or remote test switch ensure that the detector will properly sample the air stream?

Notice that I didn't disagree with you, only pointing to what some manufacturers permit under their inspection and testing instructions.

As for testing duct detectors with sampling tubes, that usually requires setting off a smoke bomb near a return register or directly in the duct. The next customer that lets us do that will be the first.

 

[Eaglesionu]

Thank you everyone for your response. I'm trying to decide how to move forward with the continous duct detector issues we are having. Everyone pointing fingers at everyone else, Duct detectors never functioning properly, customer not getting the detectors repaired. Alot of time is wasted trying to expalin to the customer that they need to get things fixed just for it to fall on deaf ears.

On one had, the only way to really test a duct detector is with smoke. However, testing with smoke is not practical, efficent or cost effective. At the end of the day its just "how much liability am i willing to live with" to keep a customer from finding another vendor who will just provide them the inspeciton report that they want....

 

[Eaglesionu]

NFPA 72 accepts whatever method is approved by the duct detector's UL listing. So, magnets are fine for System Sensor DH100 series, and remote test switches for others. I agree that you really need to put smoke in the chamber to get a true functional test, but I don't make the rules.

NFPA 72 2022 indicates that duct type smoke detectors must be tested Annualy in a way that will ensue that they properly sample the airstream. This is drectly in the testing requirements section under "method."

Furthermore NFPA 72 2022 is now avaliable thru iLink and there is alot of clarification and comments from NFPA 72. Within the Table Commentary for 17(7)(a) the clarificaiton indicates that test button or magnets are absolutley not accepted....

So the "manufacutrer instructions said so" doens't apply anymore IMHO.

 

[hillofthorns]

Thank you everyone for your response. I'm trying to decide how to move forward with the continous duct detector issues we are having. Everyone pointing fingers at everyone else, Duct detectors never functioning properly, customer not getting the detectors repaired. Alot of time is wasted trying to expalin to the customer that they need to get things fixed just for it to fall on deaf ears.

On one had, the only way to really test a duct detector is with smoke. However, testing with smoke is not practical, efficent or cost effective. At the end of the day its just "how much liability am i willing to live with" to keep a customer from finding another vendor who will just provide them the inspeciton report that they want....

Another way to verify the correct airflow, which is mentioned in NFPA 72, is a manometer. That may actually be suited more to the HVAC company side of things, but I'm not sure I'd trust the extra hands in pot for FA testing. Would be good to do at an acceptance at least, not that it ever is. Not cost effective at an annual. Smoke tests are worth it on annuals imo, plenty of times the detector is clogged up or the housing is damaged and can't seal.

 

[Eaglesionu]

Another way to verify the correct airflow, which is mentioned in NFPA 72, is a manometer. That may actually be suited more to the HVAC company side of things, but I'm not sure I'd trust the extra hands in pot for FA testing. Would be good to do at an acceptance at least, not that it ever is. Not cost effective at an annual. Smoke tests are worth it on annuals imo, plenty of times the detector is clogged up or the housing is damaged and can't seal.

How are you performing a smoke test in the real world?

Just using the smoke port on the front of the duct detector?

Sending smoke thru the return? How much smoke does that take!? What about a large, existing, site with no HVAC plans? How are you accounting for the time it takes to find the proper return that will trigger the duct detector?

 

[gadfly56]

How are you performing a smoke test in the real world?

Just using the smoke port on the front of the duct detector?

Sending smoke thru the return? How much smoke does that take!? What about a large, existing, site with no HVAC plans? How are you accounting for the time it takes to find the proper return that will trigger the duct detector?

Manometer testing is one of the ways to verify air flow.

There are one or two AHJ's in NJ that require you set off a smoke bomb near or in a return to satisfy testing.

 

[gadfly56]

NFPA 72 2022 indicates that duct type smoke detectors must be tested Annualy in a way that will ensue that they properly sample the airstream. This is drectly in the testing requirements section under "method."

Furthermore NFPA 72 2022 is now avaliable thru iLink and there is alot of clarification and comments from NFPA 72. Within the Table Commentary for 17(7)(a) the clarificaiton indicates that test button or magnets are absolutley not accepted....

So the "manufacutrer instructions said so" doens't apply anymore IMHO.

Since NJ is still on the 2019 edition, we're still good, for limited values of that word, with the manufacturer's test method (Table 14.4.3.2, part 17.(7)(e))

 

[hillofthorns]

How are you performing a smoke test in the real world?

Just using the smoke port on the front of the duct detector?

Sending smoke thru the return? How much smoke does that take!? What about a large, existing, site with no HVAC plans? How are you accounting for the time it takes to find the proper return that will trigger the duct detector?

During an annual inspection (most of what I do) I will test using the test port (current Siemens) or pop the cover if needed for other brands. 90% of the duct detectors I test are a Siemens OP921, and if the detector is self checking as okay than realistically the device is working. The main reason I'm actually smoking it all in that case is because I need to visually inspect the detector and it's easy to fulfill the code requirement if I'm already there.

I'm personally far more concerned with cracked, dirty, loose, or incorrectly installed housings than the smoke test. At least on annuals.

 

[gadfly56]

During an annual inspection (most of what I do) I will test using the test port (current Siemens) or pop the cover if needed for other brands. 90% of the duct detectors I test are a Siemens OP921, and if the detector is self checking as okay than realistically the device is working. The main reason I'm actually smoking it all in that case is because I need to visually inspect the detector and it's easy to fulfill the code requirement if I'm already there.

I'm personally far more concerned with cracked, dirty, loose, or incorrectly installed housings than the smoke test. At least on annuals.

This is what we expect our techs to do.

 

[mtnelect]

I hope you are performing these test(s) when the building is unoccupied.

 

[mtnelect]

When you perform these smoke tests in an occupied building, you are exposing the occupants to contaminates of the smoke !

 

[gadfly56]

When you perform these smoke tests in an occupied building, you are exposing the occupants to contaminates of the smoke !

If you are replying to my post at #16, the amount of smoke is not very much more than if you were testing standard ceiling mounted smoke detectors.

 

[mtnelect]

At one point in my business, we performed duct cleaning services at schools and other commercial buildings. We always required that the building was not occupied because of liability concerns. It was always done under negative pressure, so the chance of contamination of the air supply was small. The biggest chance of contamination was when the HVAC system was turned back on !

Also, did fire alarm testing and additions at private schools, same procedures, that was easier since it was always on weekends.