Indoor climate FAQ.

Outdoor air sits at around 420 ppm. A room in use with good air change typically stays below 800 ppm. Between 800 and 1,200 ppm the air is getting used up, and above 1,200 ppm the air change is insufficient for the number of people in the room.

No, not in itself — the levels found in ordinary buildings are far below anything harmful to health. CO2 is used as an indicator: when the figure is high, the room's air is not being changed, and everything else builds up with it — moisture, odours and airborne particles. That usually shows up as tiredness, heaviness and poorer concentration.

In the occupied zone — where people actually are — and not right next to a window, a door or an air inlet, where fresh air would fool the reading. One sensor per room is the starting point; large or subdivided rooms may need more.

Yes. You set up a notification on the sensor with the threshold and sensitivity you want, and you receive an email or text message when it is breached. The sensitivity determines how long the level has to stay above the threshold before the message goes out — so you hear about real problems, not about every packed meeting.

The most widely used thresholds (800/1,200 ppm) apply to offices, schools and similar rooms under EN 16798-1. But a lecture theatre, a sports hall and a server room place different demands — which is why each room is assigned a scenario with thresholds suited to how it is used, and the system colours everything according to those.

The directive (EU 2024/1275, Article 13) requires building owners to document the indoor climate as part of the building's performance, with EN 16798-1 as the reference standard. How that plays out in practice depends on national implementation, so the specific obligation for your particular buildings should be settled with your consultant or the relevant authority. The directive applies across EU and EEA markets; in the UK, the same requirements are usually met through certification schemes such as BREEAM, DGNB and LEED and through the domestic EPC rules rather than through the directive itself.

At least temperature, humidity and CO2 in every zone to be documented. The number follows the room type — a single office under 50 m² manages with one, while an open-plan office is usually counted at one to two sensors per 100 m².

Because only sensors with an assigned EPBD scenario are shown. The scenario is what sets which comfort category the room is measured against, and without it the report does not know what to calculate compliance against. It is assigned under Administration → Thresholds.

At least three months gives a statistically representative picture, and for full-year compliance you should report at least once a year. If the climate control is strongly seasonal, quarterly reports give a truer picture than a single annual one.

No. It documents what has been measured and how that relates to the categories in EN 16798-1. Assessment, approval and any reporting sit with the authority, auditor or consultant — we do not certify, and we do not replace a qualified survey of the building.

In rooms where people spend time, 35–65 %RH is a reasonable band. Below 30% the air feels dry, and above 70% the risk of condensation on cold surfaces rises. Museums and archives work to different bands — Bizot Green 2023, for example, uses 40–60 %RH with no more than ±10 %RH of fluctuation in 24 hours.

Because cold outdoor air holds very little water. When it is warmed to room temperature it can hold far more water than it brought with it, and the relative humidity falls. The colder it is outside and the more you ventilate, the drier it gets indoors. It shows clearly when you put outdoor temperature and indoor humidity on the same chart.

Relative humidity is a percentage of what the air can hold at the current temperature — it changes when the temperature changes, even if the amount of water stays the same. Absolute humidity is the actual amount of water in grams per cubic metre. When you want to know whether moisture has genuinely entered the room, absolute humidity is the figure to look at.

It can tell you whether the climate supports mould growth, and how long it has done so. That is what the mould index from the VTT model expresses on a scale from 0 to 6. It cannot see whether mould is already sitting behind a cupboard — a high index is a reason for a physical inspection, not a finding of damage.

The sensor measures the air, not the surface, so put it in the occupied zone close to the exposed area rather than squeezing it in behind the cupboard. The combination of the room's humidity and the dew point tells you how cold a surface has to be before water settles on it — and that is the calculation that shows whether the cold corner is at risk.

Time when the reading sits outside the sensor's applicable thresholds — either below or above. If the sensor has been assigned a scenario, the scenario's figures apply, including the difference between summer and winter. Otherwise the sensor's own thresholds are used.

Longest measures duration: how many hours in a row the room sat outside the band. Largest measures distance: how far from the threshold it went. A room can top one list and not appear on the other at all, and they typically point to different causes.

Not necessarily. Eight per cent spread across a whole month in a room that sees little use is a different matter from eight per cent falling between 13:00 and 15:00 every weekday. Look at the 24-hour distribution before your team draws conclusions — it is the distribution that points to the cause.

Yes. Status can be reported for a whole location rather than a single sensor, and the ranking shows locations against one another until you expand one of them into individual rooms. If your team has limited location access, you only see the locations you have access to.

Outdoor sensors are kept out, so a warm summer's day outside does not contaminate the indoor picture. Rooms standing empty do count, though, if they have sensors and thresholds — which is often the whole point, because a store or a server room has to hold its climate whether anyone is there or not.

A preset set of thresholds for temperature, humidity, CO2, VOC and sound level, tailored to a room type and with separate summer and winter thresholds. It decides when the room shows green, amber or red — everywhere in the system, from the dashboard to the reports.

Because the two rooms each protect something different. The office follows EN 16798-1, with the focus on human comfort. The store follows preservation standards such as Bizot Green or ASHRAE, with the focus on protecting objects from swings in temperature and humidity. The same climate can be comfortable for people and damaging to a wooden sculpture.

The School classroom scenario has a green zone up to 800 ppm and an amber zone up to 1,200 ppm. Above 1,200 ppm is the red zone. The thresholds follow EN 16798-1 category II and the Building Regulations.

Yes. Under Administration → Thresholds you create a new scenario and define the thresholds for every parameter yourself. Your own scenarios sit in a group of their own, are not shared with other accounts, and have no standard behind them — they are your own figures, and it says so.

The scenario becomes the room's yardstick from then on, and the charts use the catalogue's figures wherever a scenario is assigned. If a sensor has thresholds of its own, they are used only where there is no scenario. If you want to adjust the scenario's figures for that particular sensor, it can be applied and the values then fine-tuned.

One per thermal zone is the minimum. An ordinary office under 50 m² manages with one. An open-plan office is typically counted at one to two per 100 m², and a room with windows facing both north and south should have one at each end, because the two sides behave differently across the day.

It depends on the type. Full+ sensor and Mini+ sensor measure to ±0.1 °C, the Temperature sensor to ±0.25 °C, and the older A-series sensors to ±0.3 °C. Drift is under 0.03 °C a year for the newer sensors, so a sensor stays reliable for many years. That is enough for operational monitoring, but it is not an accredited measurement.

You can document what was actually measured during occupied hours, and that is often what the discussion is about. But RoomAlyzer sensors are operational monitoring, not an accredited health and safety measurement. They work well as input to a thermal comfort risk assessment, which is what the HSE expects when employees complain, but a formal measurement sets requirements for measuring height and radiant shielding among other things, and placement is your own responsibility.

First check whether there is a relocation marker on that day in the chart. If the sensor has been moved to another room, the curve describes two different rooms before and after, and the jump does not belong to the room. If there is no marker, the usual explanations are a window that has been opened, sun on the façade, or a system that has changed its operating mode.

That is often the most interesting part. A night setback to 16–17 degrees outside occupied hours is common practice, but it only works if the building can get back to comfort in the morning. With continuous monitoring you can see both: whether the setback actually happens, and whether the rooms are ready when people arrive.

Both are possible, and you choose per rule. Recipients do not have to be users in the system — you can send to a facilities inbox or to an on-call phone. The language is set per rule too, so a German operations partner can get the message in German, even though you may well work in English, Danish or Swedish.

Adjust the sensitivity so a brief breach does not count, and consider whether the threshold is set right for that particular room. If it is a recurring pattern you already know about — the meeting room after lunch — it is usually not an alarm, but something to solve with ventilation or meeting scheduling.

Yes. Every rule has a toggle that turns it on and off without you losing the setup. That is the right approach during refurbishment, a holiday shutdown or while a plant is out of service — better than deleting the rule and trying to remember it afterwards.

Yes, for humidity fluctuations. The Bizot fluctuation alert looks at the difference between the highest and the lowest humidity over 24 hours and only responds once the threshold has been crossed for a number of consecutive days. It is sent by email only, and it is intended for collections and materials, not for comfort.

Whoever can do something. An alarm to a shared inbox with no owner is not really an alarm at all. In practice two recipients often works best: the operations manager who acts, and a shared inbox so the message is not lost while someone is on holiday.

No. Air quality is part of the indoor climate — typically CO2 and VOCs — but the indoor climate also covers the thermal side (temperature and humidity) and often sound and light. So when someone says 'poor indoor climate', it can cover four different problems. Ask what they noticed, and measure all three core parameters so your team does not solve the wrong one.

There is no single answer for every room. An ordinary office under EN 16798-1 category II sits in the green at roughly 22–26 °C in summer, 35–65 %RH and below 800 ppm CO2. A school classroom uses the same CO2 band. A museum store, by contrast, is governed by the preservation of the objects rather than by human comfort. Choose the band according to how the room is used, and follow it during the hours the room is occupied.

The Building Regulations set requirements for how a building is designed and constructed, and that is demonstrated with calculations before anyone moves in. The indoor climate in operation is how the rooms behave afterwards — with real people, sun, furniture and habits. The two do not contradict each other. A continuous series of measurements answers the operational question, but it does not replace the documentation from the building control process.

Start with temperature, humidity and CO2 in the rooms where people spend long periods and where the complaints come from. VOCs, sound and light matter when chemicals, noise or lighting are part of the problem — not as standard in every store cupboard. One sensor in the occupied zone per room is the starting point; large or subdivided rooms may need more.

Yes. The sensor list and the dashboard are for the person who wants to look. Notifications are for the person who just wants to be told when a threshold is crossed. Charts by email and scheduled location reports arrive in the inbox automatically. And the AI assistant under Indoor climate → Tools answers questions like 'what time of day is CO2 highest?' based on your own measurements.