Meridian Series
Self-modulating draft control for gas-fired appliances
Meridian measures the flue and the space it serves, then modulates the draft inducer continuously on that pressure differential to provide only the draft the appliance needs. Quiet, fully automatic, and no commissioning required.
- 01 · MeasureThe flue and the space it serves
- 02 · CompareThe differential between them is draft
- 03 · ModulateXV-FLUX adjusts continuously
- 04 · ProveDraft proven before the appliance lights
- 05 · ReportNative BACnet and Modbus
Modulation
Draft, measured against the space it serves.
Most draft controls hold a fixed stack setpoint. Meridian references two pressures, the flue and the space the appliance serves, and controls the difference between them. That differential is draft itself.
When exhaust equipment pulls the space negative, the differential drops and Meridian responds by pulling harder. When conditions ease, it backs off. The draft inducer only works as hard as the moment requires.
No speed to set and nothing to dial in at commissioning.
Quiet
Quiet because it only works as hard as it has to.
A fixed-speed draft inducer runs at the speed its worst day needs, every hour it runs. Meridian runs at the speed this moment needs. When the weather is calm and nothing is pulling the space negative, that can be well below full speed.
Sound falls sharply as speed comes down. At reduced speed, XV Series draft inducers tested 23 to 34 dB quieter than full speed (38 V test point). To the ear, every 10 dB drop sounds about half as loud.
Quiet is not a setting. It is what happens when the fan runs only as fast as the moment needs.
Tested sound dataSequence of operation
Meridian proves draft before the appliance lights.
- 01
Call for heat
The appliance's own control initiates the call. Meridian never fires the appliance.
- 02
Draft inducer starts
The draft inducer starts as soon as the call comes in.
- 03
Damper proves open
Where the flue has a damper, Meridian confirms it is open before going further. If it does not prove open, the appliance does not light. X-VENTISO dampers fail open.
- 04
Positive draft established
XV-FLUX drives the flue-to-space differential to setpoint and proves positive draft.
- 05
Appliance released
Only with draft proven does the interlock release the gas appliance module to light.
- 06
Continuous modulation
Meridian holds the setpoint as conditions change: wind, stack temperature, and exhaust equipment pulling the space negative.
- 07
Call ends, flue purged
When the call ends, the draft inducer runs a 15-second post-purge to clear the flue, shown on Meridian's display, then shuts down.
- 08
If draft is lost
If draft cannot be held at any point, Meridian shows an alarm on its display, shuts the gas appliance down through the interlock, and runs the post-purge to clear the flue.
In the box
Everything code asks for, in the box.
| Included | Meridian | Meridian DUO |
|---|---|---|
| Plugs into a standard 120V outlet | Included | Included |
| Factory-wired, plug-in Molex connections | Included | Included |
| Stack probe and pressure tubing | Included | Included(one set per flue) |
| Damper proving, where a damper is used | Included | Included(each flue) |
| Draft proven before ignition | Included | Included |
| Gas interlock (NFPA 54) | Included | Included |
| Alarm | Visual, on display | Visual, on display |
| Service disconnect at draft inducer | Included | Included |
| Native BACnet and Modbus | Included | Included |
Meridian is for gas-fired appliances. For solid fuel, specify Controlled Power WBC, which carries the audible and visual alarm NFPA 211 requires. Requirement-by-requirement detail on the Code Compliance page.
BAS integration
Native BACnet and Modbus.
No gateway required. Meridian reports status, alarm, draft pressure, fan speed, and damper position, and accepts an enable / disable command from the building automation system.
Automation can turn Meridian on and off. It never fires the appliance. The gas interlock stays with Meridian.
Protocol variants, object list, and register map in the BACnet PICS and Modbus register map (coming soon).
| Point | Access | Description |
|---|---|---|
| Run status | Read | On / off |
| Draft pressure | Read | Flue-to-space differential, in. w.c. |
| Alarm status | Read | Active / clear, including loss of draft |
| Fan speed | Read | Draft inducer speed |
| Damper position | Read | Open / closed |
| System enable | Write | Enable or disable the Meridian system. Does not fire the appliance. |
Compatibility
One system, factory matched.
Draft inducers
XV150 · XV250 · XV350
Factory-wired, plug-in 3-pin Molex.
Dampers
Gas top-mount and inline
4-pin Molex, any size. Damper position reported to BAS.
Flue silencers
WSPRDraft, 8" to 16"
Tested to ISO 7235.
Vibration dampeners
Urethane mounts, sized C-springs
Mounts between the flue adapters.
Makeup air
VMASS
Interlock VMASS with the same call through XV-INTG.
Integration
XV-INTG
One low-voltage call to multiple Meridians, or Meridian with VMASS.
Specifications
Meridian specifications.
| Specification | Meridian | Meridian DUO |
|---|---|---|
| Model number | XV-MERD-CTRL | XV-MERD-DUO |
| Fuel | Gas-fired appliances | Gas-fired appliances |
| Flues served | 1 | 2, controlled independently |
| Pressure transducers | 1 | 2, one per flue |
| Reference | Flue and served space | Each flue to its own served space |
| Modulation | XV-FLUX, continuous | XV-FLUX, continuous, per flue |
| Commissioning | None required. Nothing to dial in. | None required. Nothing to dial in. |
| Draft proving | Pressure, stack probe and tubing included | Pressure, stack probe and tubing included |
| Gas interlock | Interlocked with the appliance gas control | Interlocked with the appliance gas control |
| Alarm | Visual, on display | Visual, on display |
| BAS | Native BACnet and Modbus | Native BACnet and Modbus |
| Power | Plugs into a standard 120V outlet (NEMA 5-15 plug) | Plugs into a standard 120V outlet (NEMA 5-15 plug) |
| Electrical rating | 120 VAC, 50/60 Hz, 6.0 A | 120 VAC, 50/60 Hz, 12.0 A |
| Enclosure | NEMA 1 (indoor). Sealed at the factory; no field-serviceable parts | NEMA 1 (indoor). Sealed at the factory; no field-serviceable parts |
| Listings | UL 508 Industrial Control Panels · UL/ULC 378 Draft Equipment. ETL Listed, Intertek control no. 4007025 | UL 508 Industrial Control Panels · UL/ULC 378 Draft Equipment. ETL Listed, Intertek control no. 4007025 |
Controllers are factory-sealed. Opening the enclosure voids the warranty.
Downloads
Documents and drawings.
- Submittal SheetPDF · Coming soon
- Installation ManualPDF
- CAD DrawingsConfiguration drawingsWith TMD PDFInline PDF
- Guide SpecificationAvailable on request
- BACnet PICSPDF · Coming soon
- Modbus Register MapPDF · Coming soon
- Listing CertificatePDF · Coming soon
- Code ComplianceCode Compliance page · Coming soon