Filter Monitor User Guide

1Overview

What Filter Monitor does, who it is for, and the problem it solves.

A dirty air filter announces itself as a rising pressure drop across the element. Filter Monitor reads that pressure drop from an NCD differential pressure sensor plumbed either side of the filter, and turns it into the one number a maintenance planner needs: how much of the element’s usable life has been consumed.

The alternative is changing filters on a calendar. That is either wasteful — a clean element goes in the skip because ninety days elapsed — or late, and a loaded filter costs fan energy, starves coils and eventually collapses into the air stream. Neither failure is visible from the corridor. A pressure drop is.

The complication that makes this harder than reading a gauge is airflow. Pressure drop across a filter rises with air velocity as well as with dust, so the same element reads near zero with the fan off and reads high when the unit ramps. A reading taken at the wrong moment looks like a brand-new filter or a blocked one. Filter Monitor handles this explicitly: each filter has an airflow threshold, readings below it are not scored at all, and when the system is idle the app holds the last severity it measured under airflow rather than reporting a falsely clean result.

2Requirements

What the app needs before it will do anything useful.

Supported sensors

All three report a differential pressure with its unit attached, which is what allows one app to read them identically. Each has its own firmware floor. A sensor below its floor is still listed when you pick a sensor, with the reason shown, rather than quietly going missing.

Plumbing the sensor

The sensor has two pressure ports. Run one tube to the upstream (dirty) side of the filter and the other to the downstream (clean) side. The sensor is bidirectional, so a reversed pair still produces valid data — it simply reads negative. The setup wizard detects this while you are connecting the tubes and offers to correct it, so there is no need to get it right first time.

3Installing

From the App Center, or from a package file.

1. 1
   Open the App Center

   Log in to the gateway dashboard and select Apps in the top navigation. On the Apps page, click Browse App Center. The catalog opens over the page and lists every app published for Atrium gateways; the ones already on this gateway carry an INSTALLED badge with their version.

2. 2
   Install Filter Monitor

   Find Filter Monitor in the App Center and install it. If you were sent a package file instead, use the upload control on the same page.

3. 3
   Wait for the gateway to reload

   Installing an app restarts the gateway’s services. This takes a few seconds and interrupts nothing permanently; the page reconnects on its own.

4. 4
   Open the app

   Filter Monitor now appears as a card on the Apps page. Select it to open.

4First-Time Setup

The shortest path from a fresh install to a graded filter.

1. 1
   Open the app

   Go to the Apps tab and select Filter Monitor.

2. 2
   Choose the unit you want pressures shown in

   The Show pressures in control at the top left offers in w.c., Pa, mbar, kPa and psi. This is a display choice and applies everywhere in the app; it changes nothing about how filters are scored. The default is in w.c.

3. 3
   Click + Add filter

   The setup wizard opens over the page in five steps: Identify, Filter type, Thresholds, Sensor and Review. Each step is described under Adding a filter.

4. 4
   Complete the wizard and click Create filter

   The filter appears in the list immediately, showing No data until enough readings have arrived.

5. 5
   Wait for the first readings

   A filter needs at least three readings taken while air was moving before it can be scored. With a sensor reporting every ten minutes and the fan running, that is about half an hour. If you left Learn the clean pressure automatically ticked, the baseline is measured over the following 24 hours and the card shows Learning its clean baseline from running airflow until it completes.

5The Filter List

The app opens on the filter list. Everything above the cards stays on screen while the list scrolls, so the controls and the counts remain usable however many filters there are.

Controls

Severity counts

Below the controls is a row of counts, one per severity, with All at the front. Selecting a count filters the list to that severity; selecting All returns to the full list. Above them is a one-line verdict for the whole site — for example All filters healthy, 2 filters need replacing or A sensor has stopped reporting.

A sensor that has stopped reporting ranks below filters that actually need replacing but above everything else. The app will not claim “All filters healthy” while it has lost contact with a sensor, because that would be claiming knowledge it no longer has.

This five-step scale is Atrium’s own presentation convention, not a published filter standard. The thresholds that define 0% and 100% for each element are the ones you configure; the bands between them are the app’s.

Filters are listed worst first, then by used life, then by name.

The filter card

Every card carries the same elements in the same positions whether or not anything is wrong, so a wall of filters can be scanned without the eye having to re-find each figure.

How used life is calculated

Used life is the fraction of the way from the clean pressure to the replacement pressure:

used life % = (median pressure − clean pressure) ÷ (replacement pressure − clean pressure) × 100

The median pressure is taken from readings within the evaluation window (6 hours by default) that were taken while air was moving and that were recorded after the current element went into service. Readings from before the element was installed are never scored, which is what stops the old filter’s high pressures out-voting the new one’s after a change. The figure is recalculated whenever the sensor reports.

Airflow states

Why a filter may show No data

The status note gives the specific reason: no sensor linked, learning its clean baseline, no airflow detected, no readings from the sensor yet, waiting for the first reading since this element went into service, or not enough running readings yet.

6Adding a Filter

+ Add filter opens a five-step wizard over the page. You can move back with ← Back at any point, and abandon the whole thing with Cancel, the close button, a click outside the window or the Escape key. Nothing is written until you click Create filter on the last step.

Step 1 — Identify

Step 2 — Filter type

This step picks sensible starting pressures, which you can change on the next step. The exact figures are on the element’s datasheet.

Rating standard

Each option carries an information dot describing what the standard is, how it works and what it is used for.

Choosing a standard offers a list of classes within it. Selecting a class fills in typical clean and replacement pressures for that class, which the next step lets you override.

Form factor

Recorded for reference; it does not affect scoring. Options are Not specified, Pleated panel, Flat panel, Bag / pocket, Rigid box / mini-pleat, V-bank, Cartridge and HEPA cell. The default is Not specified.

Nominal size and Elements in the bank

Both are recorded for reference and do not affect scoring. Nominal size is free text, for example 24x24x2. Elements in the bank defaults to 1 and is there so a multi-element bank monitored by one sensor records how many elements a change order covers.

Step 3 — Thresholds

These are the numbers the percentage is measured between: 0% at the clean pressure, 100% at the replacement pressure. All values are entered in whichever unit is selected in Show pressures in.

Step 4 — Sensor

Pick the sensor measuring this filter. Sensors are listed by their name on the gateway with their address, so you do not need to work from a MAC address — but the link is stored against the address, so renaming a sensor later does not break it.

Selecting a sensor shows its pressure chip and measuring range, as the sensor reported at its last check-in, and then begins polling for a Live reading.

The live plumbing check

This is the reason to connect the tubes before finishing the wizard rather than after. The sensor is bidirectional, so tubes on the wrong ports produce a consistently negative reading rather than an obviously broken one.

• Reading positive — the tubes are the right way round. Nothing to do.
• The reading is consistently negative, which means the tubes are on the wrong ports. Either swap them at the sensor, or click Reverse polarity to have the app invert the sign for this filter.

The measuring range warning

The Gen4 (type 131) is the exception: it reports its range on every data frame rather than at a configuration check-in, so the app knows which Honeywell ADP part is fitted as soon as the sensor reports, with no pairing step.

Step 5 — Review

A summary of everything entered, plus two optional fields.

Set the timeout yourself when the reporting interval recorded against the sensor is out of date, or when a longer grace period suits the site.

Create filter saves it. The filter appears in the list immediately; its pressure trend does not open by itself.

7Pressure Trend

The View trend button on a card opens that filter’s pressure history in a window over the dashboard. Close it with the close button, a click outside or the Escape key.

The window is headed by the filter’s name with the sensor’s address beneath it. It opens on the last 24 hours.

The chart

Figures below the chart

Each carries an information dot. These are the facts the chart needs explaining, rather than a repeat of the card behind it.

Service history

A dated log of what has happened to this filter — when it was created, when the element was replaced, when a baseline was learned. It scrolls after three entries rather than growing the panel.

8Editing, Replacing and Removing

Mark replaced

Click the Mark replaced button on the card after physically changing the element, and confirm. This resets the installed date to now, clears the verdict and restarts the alert so a future replacement can email again.

Readings recorded before that moment are never scored again. This is what stops the old element’s high pressures out-voting the new one’s, and it means the card reads Waiting for the first reading since this element went into service until the sensor next reports, rather than carrying the old verdict.

Facts that belong to the sensor rather than the element — when it last reported, the highest pressure it has ever observed, its measuring range — survive a replacement, because replacing a filter says nothing about the sensor.

Edit

The pencil button opens the filter’s settings without removing and re-adding it. Name, location, asset tag, size, the three pressure thresholds, the linked sensor, polarity, the alert address and the Data Timeout Limit can all be changed. Changing a threshold re-scores the filter immediately.

In service since

The edit window also exposes the installed date, with a Start fresh now button beside it. Nothing recorded before this moment is ever scored.

Remove

The red trash button removes the filter and its history from the app, after a confirmation. It does not affect the sensor, and it does not delete any readings — those belong to the gateway.

Notices

An amber warning icon appears among the actions when a filter has something to report, with a count when there is more than one. Clicking it opens a window carrying the filter’s name, its sensor address and the full text. Warnings live here rather than on the card so that cards keep a uniform height.

10Settings

Two settings are on the toolbar: Show pressures in and Median over … readings. Both are described under Controls. The remaining settings below are applied per gateway and shared by every filter.

Changing any of these re-scores every filter immediately.

Credentials and email

The app holds no credentials. Alert email is sent through the gateway’s own configured SMTP server, so the address, server and authentication are managed on the gateway rather than in this app. The only thing stored per filter is the destination address.

Limits

There is no licensed limit on the number of filters. Each filter needs its own sensor; one sensor cannot serve two filters, because the app scores one pressure drop per element.

11Troubleshooting

12Reference

Units

Pressures are held internally in Pascals and converted for display. Changing the display unit never changes a stored value or a verdict.

Severity bands

Applied to used life. These bands are Atrium’s presentation convention, not a filter standard.

Standards referenced

The preset clean and replacement pressures offered per class are typical figures for that class, provided as a starting point. They are not taken from any one manufacturer, and the element’s own datasheet always takes precedence.

Timings

Data stored by the app

Filter definitions, thresholds, the linked sensor address, polarity, alert address, timeout override, the current verdict per filter and a service history of element changes and learned baselines. No telemetry. Readings are read from the gateway and are kept under the gateway’s own retention settings.