# 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 tracer cycle match

outdoor ↔ indoor

### Resolution

Zone-level breathing zone

### Cadence

Continuous 24 / 7 / 365

### Standard

ASHRAE 62.1

### Integration

None no BMS, no Wi-Fi

## How it works

### Four steps. No BMS required.

No step uses BMS data, damper feedback, or CO₂ proxy. DVM relies only on physical atmospheric tracer concentrations measured in place.

`MONITOR`

**Step 01**  
### Outdoor reference

Local outdoor atmospheric tracer concentrations are sampled continuously to establish the diurnal reference cycle for each site.

`continuous`

`SENSE`

**Step 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.

`continuous`

`COMPARE`

**Step 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 zone`

`SOLVE`

**Step 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 hourly`

## Measurement

### 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.

### Patent Pending

**Over-ventilated** Low delay · 2.5× code  
**At code (DVM tuned)** Medium delay · ASHRAE 62.1  
**Under-ventilated** High delay · <50% code

High Mid Low 0h 12h 24h 36h 48h Atmospheric tracer concentration Outdoor Indoor Δ Low delay

### 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.

**Reading cycle…**

Phase delay between outdoor and indoor cycles = OA intake rate, by zone

## System specs

### System parameters.

|     |     |
| --- | --- |
| 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 | CO₂ proxy |
| --- | --- | --- | --- |
| Primary signal | Atmospheric tracer-cycle match (direct) | Damper position (inferred) | CO₂ rise (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 |

## Standards alignment

### HVAC standards framework.

- ASHRAE 62.1-2022 Ventilation for Acceptable Indoor Air Quality
- ASHRAE 241-2023 Control of Infectious Aerosols
- IPMVP Int'l Performance Measurement & Verification Protocol

## DCV gap

### 70% of air consumption runs below the DCV threshold.

Demand-Controlled Ventilation cuts outside air when CO₂ climbs above its threshold. The problem: in most commercial buildings, roughly 70% of total air consumption occurs below that threshold — so DCV never engages on the majority of the operating envelope. DVM measures what you actually deliver, whether CO₂ is high or not.

### DCV · REACTIVE

Engages above CO₂ setpoint

Dormant during the 70% of operating hours where CO₂ sits below the threshold.

### DVM · CONTINUOUS

Measures across full envelope

Quantified breathing-zone ventilation — every zone, every hour.

### Scope of measurement

## The only thing that matters is what happens in the breathing zone.

Not what the rooftop 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 |
| --- | --- |
| rooftop / AHU | commanded airflow at the supply fan |
| duct / VAV | inferred volume at the terminal box |
| commissioning report | point-in-time, often 3+ years old |
| breathing zone | air actually delivered to the occupant ✓ YES |

## 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.