New HVAC Technology
Direct Ventilation Monitoring (DVM): measured, not modelled.
Poppy monitors daily cycles of outdoor atmospheric tracer concentrations and matches them to indoor levels. The difference between how they cycle outdoors vs. indoors reveals the OA intake rate for the building — so you know exactly how much outdoor air reaches each area.
Signal
Atmospheric gas concentrations
Outdoor ↔ Indoor
Resolution
Zone-Level
Breathing Zone
Cadence
Continuous
24 / 7 / 365
Standard
ASHRAE 62.1
62.1 · 241 Aligned
Integration
None
No BMS, No Wi-Fi
How it works
Four steps. No BMS required.
Unlike DCV, no step uses BMS data, damper feedback. DVM relies only on physical atmospheric gas concentration cycles measured in place.
MONITORStep 01
Outdoor reference
Local outdoor atmospheric tracer concentrations are sampled continuously to establish the diurnal reference cycle for each site.
continuousSENSEStep 02
Indoor measurement
Portable Poppy sensors placed in the breathing zone of each area record the same atmospheric tracer species at matched cadence. No BMS hookup.
continuousCOMPAREStep 03
Cycle differencing
The delta between outdoor and indoor cycles (amplitude, phase, and damping) is proportional to how much outdoor air the zone is actually pulling in.
per zoneSOLVEStep 04
OA intake rate
Poppy resolves the zone-level outdoor-air intake rate — CFM and CFM/SF — and compares it to the ASHRAE 62.1 zone target.
updated hourlyMeasurement
The indoor cycle is the outdoor-air rate.
If indoor concentrations track outdoor swings tightly, the zone is over-ventilated. If they stay flat, it's under-ventilated. Use the selector to compare profiles against the code-target band.
Atmospheric tracer concentration over 48 hours
How DVM sees your building breathe
Poppy monitors daily cycles of outdoor atmospheric tracer concentration and compares them to indoor levels. The phase delay — how far behind outdoor the indoor cycle lags — reveals the OA intake rate, zone by zone.
Phase delay
Low delay→ Energy wasted
Indoor follows outdoor almost instantly — the zone is flushed so fast that the two cycles nearly overlap. Lots of outdoor air, but far more than code requires.
System specs
System parameters.
Sensing
| Medium | Multi-species atmospheric tracer concentration (outdoor + indoor) |
| Placement | Breathing-zone portable sensors, Poppy-maintained |
| Coverage | Zone-level — one station per monitored area |
| Connectivity | Cellular uplink · no BMS, no Wi-Fi required |
Reference
| Outdoor source | Local ambient monitoring at site |
| Cadence | Continuous — diurnal cycles resolved |
| Synchronization | Outdoor and indoor sampled at matched timestamps |
Analysis
| Model | Cycle-matching of outdoor vs. indoor atmospheric tracer concentration |
| Output | OA intake rate per zone (CFM, CFM/SF) |
| Comparison | Zone target per ASHRAE 62.1 Table 6-1 |
| Savings | Weather-normalized per IPMVP Option B |
Deployment
| Timeline | Screening call → 2–4 week assessment → 72-hr report |
| Tenant impact | None — sensors are passive and in-room |
| Integration | No BMS, damper feedback, or VAV command data used |
| Ongoing | Continuous monitoring + drift alerts post-tuning |
Why DVM
DVM vs. common alternatives.
Every common approach infers outdoor-air delivery from commands or occupancy proxies. DVM measures the physical outcome.
| Dimension | DVM | BMS inference | DCV |
|---|---|---|---|
| Primary signal | Atmospheric gas concentrations (direct) | Damper position (inferred) | CO₂ levels (proxy) |
| Measures actual OA? | Yes — directly | No — commanded, not delivered | No — estimated from occupancy |
| Zone resolution | Per breathing zone | Per VAV | Per sensor |
| BMS required | No | Yes | Sometimes |
| Continuous | Yes — 24/7/365 | Yes (but inferred) | Yes (but indirect) |
| ESG / IPMVP-defensible | Yes — weather-normalized | No | No |
DCV gap
70% of air consumption runs below the DCV threshold.
Demand-Controlled Ventilation modulates outdoor air (OA) using CO₂ as a proxy for occupancy — reducing supply when CO₂ is low, increasing it when CO₂ rises. In most commercial buildings, ~70% of total outdoor air consumption occurs below the minimum DCV threshold (i.e. the area ventilation rate) — so DCV is unable to reduce OA below the level at which it activates. DVM instead measures and helps you control the OA you actually deliver, whether CO₂ is high or not.
DCV · REACTIVE
Engages above CO₂ setpoint
Dormant for 70% OA volume, where CO₂ sits below the threshold.
DVM · PROACTIVE
Full-Range Ventilation Monitoring
Quantified breathing-zone ventilation — every zone, every hour.
FIG.02b · COVERAGE OVER 24H OPERATING WINDOWthreshold = 1000 ppm CO₂Scope of measurement
The only thing that matters is what happens in the breathing zone.
Not what the equipment schedule says. Not what the DCV algorithm assumes. Not what the commissioning report logged three years ago. The occupied breathing zone is the whole point of ventilation, and it's the only place performance can be verified.
Measurement plane
What it represents
DVM target
RTU / AHU
commanded airflow at the supply fan
—
RTU / AHU
commanded airflow at the supply fan
—
Duct / VAV
inferred volume at the terminal box
—
Duct / VAV
inferred volume at the terminal box
—
Commissioning Report
point-in-time, often 3+ years old
—
Commissioning Report
point-in-time, often 3+ years old
—
Breathing Zone
air actually delivered to the occupant
✓ YES
Breathing Zone
air actually delivered to the occupant
✓ YES
Standards alignment
HVAC standards framework.
[1]ASHRAE 62.1-2022Ventilation for Acceptable Indoor Air Quality
Zone outdoor-airflow requirements (target)
[2]ASHRAE 241-2023 *Control of Infectious Aerosols
Clean-air delivery rate methodology
[3]IPMVPInt'l Performance Measurement & Verification Protocol
Option B — retrofit isolation, verified savings
* DVM measures outdoor air intake rate. Full ASHRAE 241 alignment requires a combined filtration rate assessment in addition to OA intake measurement.
Get started
Request a method brief or start a DVM assessment.
30-minute screening call. If your building qualifies, we deploy DVM sensors at no cost and deliver a 72-hour zone-level report before any setpoint change.
Schedule assessment →