Hotel & Apartment Smoke Detection Code Changes - Your Guide to Compliance

A high frequency tone around 3000 Hz is typically used to alert occupants of a fire event. Multiple studies have concluded that a low frequency 520 Hz tone is six times more effective in waking the elderly, hard of hearing, young children, and alcohol-impaired persons.

The code has already mandated the use of low frequency 520 Hz signals for sleeping rooms, to improve the waking effectiveness of all occupants. Initially the code only required these low frequency signals be initiated by the building’s fire alarm system, in areas intended to wake sleeping occupants. 120VAC smoke single and multi-station alarms were exempt.

Changes to the 2021 editions of IBC, IFC, and NFPA 101 strive to make the use of low frequency evacuation notification requirements more consistent throughout all sleeping areas. They mandate new hotels, motels, dormitories, condominiums, and apartments use low frequency audible notification signals activated by both the smoke detection in the dwelling unit and the general building fire alarm system. These new requirements apply to all R-1 and R-2 occupancies, not just units designated as ADA or hearing-impaired units.

The building code requires either a smoke alarm (UL 217) or smoke detector (UL 268) in each bedroom and outside the bedroom, along the path of egress. Smoke alarms (UL 217) are interconnected with a 3-conductor 120VAC wire but are not connected to the building fire alarm system and only initiate a local alarm. Per IBC [2021] 907.2.11.7 when system smoke detectors (UL 268) are installed in residential applications, they must be programmed as a supervisory signal so activation of a detector in a dwelling unit only initiates the notification inside the dwelling unit. It must not activate notification appliances outside of the dwelling unit or dispatch the fire department.

In 2012, UL incorporated low frequency requirements into two product standards. The first was ANSI/UL 464, Standard for Audible Signal Appliances, which is primarily used for fire alarm horns and detector sounder bases. The second is ANSI/UL 217, Standard for Single and Multiple Station Smoke Alarms, for residential 120 VAC smoke alarms. Equipment which meets this UL standard must be marked ‘Low Frequency Alarm.’ Manufacturers cannot meet the low frequency 520 Hz requirements using the traditional electro-mechanical piezo element because it cannot effectively produce the harmonics needed to comply with the standards. Instead, a speaker element, which inherently draws more current, is used to acoustically meet the 520 Hz requirements. As a result, current draw for low frequency devices are much higher.

The building code below outlines the 520 Hz low frequency notification requirements for multi-occupant residences.

IBC 2021 edition

907.5.2.1.3 Audible Signal Frequency in Group R-1 and R-2 Sleeping Rooms

Audible signal frequency in Group R-1 and R-2 occupancies shall be in accordance with Sections 907.5.2.1.3.1 and 907.5.2.1.3.2.

907.5.2.1.3.1 Fire Alarm System Signal

In sleeping rooms of Group R-1 and R-2 occupancies, the audible alarm activated by a fire alarm system shall be a 520-Hz low-frequency signal complying with NFPA 72.

907.5.2.1.3.2 Smoke Alarm Signal in Sleeping Rooms

In sleeping rooms of Group R-1 and R-2 occupancies that are required by Section 907.2.8 or 907.2.9 to have a fire alarm system, the audible alarm signal activated by single- or multiple-station smoke alarms in the dwelling unit or sleeping unit shall be a 520-Hz signal complying with NFPA 72. Where a sleeping room smoke alarm is unable to produce a 520-Hz signal, the 520-Hz alarm signal shall be provided by a listed notification appliance or a smoke detector with an integral 520-Hz sounder.

The IBC still allows 120VAC single or multiple-station smoke alarms, but they must now produce a 520-Hz signal.? Currently there are no UL 217 120VAC smoke alarms on the market with an integral 520 Hz sounder.? Due to the standby power capacity requirements, they are not cost effective to manufacture.

This new code requirement will necessitate utilizing the building’s fire alarm system with one of the following methods:

1. System smoke detectors with low-frequency sounder bases (ABHW-4BS) – preferred for standard units.
2. System smoke detectors with addressable notification or dedicated NACs for each residential unit (SL2 low frequency appliances supported by HCP or PAD-5) – preferred for ADA/ hearing impaired units requiring audible and visual coverage.

The residential unit system smoke detectors must be programmed as supervisory signals which are non-latching/ self-restoring.? This will allow them to automatically deactivate when the smoke condition clears.? Voice systems may use one of the above options with the addition of speaker appliances that have a frequency range which includes 520Hz.? Select a ?low-frequency pre-announce tone to be broadcasted before the voice message.? Siemens SL2-series high-fidelity speakers have a frequency-response range of 300 to 8000 Hz.

The use of 120VAC smoke alarms supervised by the building fire alarm system to activate system low frequency fire alarm appliances is not recommended. The drawback is that activation of a 120VAC smoke alarm would result in simultaneous activation of the integral high frequency tone and also the low frequency notification appliances connected to the building fire alarm system.? Also this method requires more equipment and wiring than just using system smoke detectors—it is not a cost effective solution.?

An addressable smoke detector with a sounder base can be programmed to function the same as a typically hard wired smoke alarm and offer several advantages:

• They offer multi-criteria detection options to more rapid and reliable fire detection.
• They use a supervised initiating circuit to assure both the wiring and detector will function as intended.? Smoke detectors derive their operating power from a centralized source. Smoke detector activity is date/ time stamped in the FACP's history log.
• NFPA 72 recommends replacing 120 VAC smoke alarms every 10 years.? System smoke detectors (with constant sensitivity?monitoring)?need to be only replaced when the FACP determines the smoke detector is defective (typical life cycle 30 years).?
• Hard-wired 120 VAC smoke alarms are not monitored.? They can be disabled or tampered.? System smoke detectors are constantly monitored and will report a 'trouble' condition along with the exact room name & number if they are tampered with or require maintenance--along with a date/ time stamp.

The minimum detector distances to avoid nuisance alarms per IBC [2021] 907.2.11.3

Audio and visual requirements

Most areas of a building must provide an alarm audio level 15 dB over ambient sound levels.? For notification signals installed in sleeping areas, the intent is to wake people up.? ?The code requires a low frequency tone of 520HZ producing a minimum of 75 dB, as measured at the pillow.? This requires an audible appliance ?in each bedroom and communal area.?

In hearing-impaired units, extra-bright strobes must be provided to wake sleeping occupants.? A higher intensity appliance is required if installed on the ceiling due to potential smoke obstruction reducing the light intensity.? From NFPA 72:

Group R-1 occupancies require a certain percentage of units contain have visual signals per Table 907.5.2.3.2.? Many hotel chains increase this number to provide visual coverage in each different room layout.? These visual appliances must be installed in ‘habitable spaces.’? The IBC defines a habitable space as “a space in a building for living, sleeping, eating, or cooking.? Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.”??

Group R-2 occupancies requiring a fire alarm system must have the capability to support strobes appliances in the future. The intent is that the fire alarm system has the capability to be modified if a hearing-impaired occupant were to move into the sleeping or dwelling unit. Compliance with IBC [2021] Section 907.5.2.3.3 future hearing-impaired adaptability is satisfied by replacement of audible appliances with combination audible/visible appliances, installing new wire when a strobe is need, or pre-wiring the unit for visual signals.

Suggested Contract Drawing Notes

This project uses system smoke detectors (UL 268) with 520Hz low frequency audible bases to meet code-required residential unit notification and smoke detection compliance.? Furnish low-voltage system smoke detectors connected to the building fire alarm system.? Provide smoke/CO detectors in designated units served by gas hot water heaters, gas cooking appliances, gas forced-air HVAC appliances, fireplaces, or direct access to enclosed parking garages.? Equipment shall be located as indicated on the design drawings. The design intent is to provide a detector in:

1. Each bedroom (sleeping area).
2. Outside the bedroom(s) in every room along the means of egress path from the bedroom (sleeping area) to the door leading from the sleeping unit.
3. On each level, if not already provided with items 1 or 2.

The system detectors shall be installed a minimum of 6 feet from any cooking appliances and a minimum of 3 feet away from bathrooms which contain a shower or tub.? Coordinate exact location and wiring requirements prior to rough-in.

The audible bases shall sound a 520Hz low frequency tone Temporal-3 pattern for a fire event and a Temporal-4 pattern for a carbon monoxide (CO) event, if applicable.? Designated ADA/ hearing impaired communication units will have additional visual signals, as shown. ?The fire alarm system shall have the ability to support future strobes programmed to activate in conjunction with the local and general audible notification sequences.

Residential unit sequence of operations:?

1. Activation of a detector within a residential unit shall initiate audible signals only within that unit and provide a supervisory signal at the fire control panel in accordance with IBC Section 907.2.11.7.? Program the detectors as self-restoring.?
2. Activation of a general building alarm shall initiate audible signals in all sleeping units.??
3. Designated ADA/ hearing-impaired communication units shall also activate visual signals in conjunction with audible signals.?
4. Systems utilizing speaker appliances shall silence any active non-speaker audible appliances when a voice message is broadcast.

Where the mechanical design requires residential unit fire/ smoke dampers to prevent smoke migration, in addition to the notification sequence, a smoke event within the unit shall close the residential fire smoke damper(s) and provide notification to the BAS.? Coordinate fan and damper override shutdown sequence with the mechanical design to avoid over pressurization.

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