What is a good indoor climate?

In human terms, a good indoor climate translates to a great feeling and a rejuvenating space where you experience clarity, comfort, and a sense of ease. In scientific terms, a good indoor climate can be quantified by numbers which encompass the levels of CO₂, humidity, the temperature, and an absence of mold, pollen, and other air pollutants. But achieving a good indoor climate shouldn’t be seen as a mammoth task. You can get there with simple, tried and tested habits employed throughout your daily routine.

What is a good indoor climate in numeric terms?

A good indoor climate is a balancing act, where air, temperature, and humidity work together to make you feel comfortable, clear-headed, and at ease. In measurable terms, it means keeping CO₂ below 1,000 ppm, humidity between 40–60%, and avoiding pollutants like mold, pollen, and dust. Temperatures of around 20–23 °C during the day (and about 17-18 °C for sleep). This also depends on how much you 

Here are our answers to some questions you might have on what it takes to achieve the best indoor climate possible.

How do I know when my indoor air is fresh enough?

Stale air makes you tired and unfocused, fresh air makes you feel awake and alert, it’s as simple as that. CO₂ levels above 1,000 ppm is considered stale air and can affect how alert and productive you feel. So when you feel groggy, or you see your 🐤 Birdie® is down, it’s a sign your air isn’t as fresh as it should be. 

💡 Tip from Birdie: If you don’t want to leave your windows open for a long time, short bursts (10–15 minutes) every few hours can still be effective at rejuvenating your indoor climate. <h3> Keep the temperature at the right level for comfort, focus, and sleep quality

Comfort is above all a personal preference, but if you want something to aim for, 20–23 °C during the day is considered suitable for comfort.

For productivity it’s likely you’ll thrive in a slightly warmer environment, people with a lower metabolic rate will likely need the temperature higher than others as they generate less heat. An ideal temperature for productivity can be anywhere between 21-24°C.

For sleep, cooling things down to around 17–18 °C has been scientifically linked to better sleep quality in adults as it allows your core body temperature to drop, signalling to your brain it can rest. 

💡 Tip from Birdie: If you don’t want to remember numbers just try to recall this; cooler for sleep, warmer for work, balanced for wellbeing.

What’s the ideal humidity for a good indoor climate?

Humidity can be tricky to manage, too dry, and you’ll feel scratchy; too damp, and you’ll risk mold. 40–60% relative humidity is the goldilocks zone for the indoor climate that’s just right.

💡 Tip from Birdie: Bathrooms and kitchens are humidity hotspots, take special care to ventilate them properly after use. 

How to minimise pollen getting indoors? 

Pollen season runs March to September, and for those with allergies or hayfever, it can be a daunting time to go outside. While the outdoors isn’t in your control, you can avoid pollen ruining disrupting your indoor climate by following these steps: 

• Keep windows closed during peak pollen hours (morning and afternoon).
• Change clothes after being outdoors, just like it sticks to bees, pollen sticks to clothing.
• Use an air purifier with a HEPA filter to trap pollen particles that have managed to get inside. 

💡 Tip from Birdie: To keep your indoor climate fresh during pollen season, open your windows to ventilate only after rainfall and in the evening to avoid the daily spikes of pollen present in the air. 

How to minimise mold indoors? 

Mold isn’t just unsightly, it can be dangerous if not managed properly. Here are some tips to help you maintain a good indoor climate and prevent mold growth:

• Keep humidity under 60%.
• Wipe condensation from windows and walls.
• Ventilate after the bathroom after showers or your kitchen after cooking.
• Leave a small gap between walls and furniture so air can circulate.

💡 Tip from Birdie: Mold can grow fast, sometimes in under 48 hours, so good habits where you ensure spaces get frequent airflow to reduce their moisture levels can make all the different.

When’s the best time to let fresh air in?

Even the best indoor air depends on what’s happening outside, and not all outdoor air is as fresh as you’d think. If the air looks thick or you smell smoke or chemicals, it might not be the best time to freshen up your indoor climate. Here are some tips to ensure a good indoor climate even when the outdoor air isn’t the best: 

• Check your local AQI (Air Quality Index) before opening windows.
• Ventilate only when AQI is below 50 or after rain.
• Use an air purifier with HEPA filter, during high pollution days.

What’s the ideal temperature for relaxation? 

When you’re winding down, comfort is king and it’s mainly a preference thing. But if you keep your space between 20–23 °C, you can’t go too far wrong. 

💡 Tip from Birdie: Cosy doesn’t have to mean closed, it’s ok to drop the temperature with a brief window open to refresh your space.

What’s the ideal indoor climate for productivity and focus?

A good baseline for an optimal indoor climate for productivity is a temperature: 21–24 °C, humidity between 40–50%, and above all CO₂ levels below 1,000 or ideally 600.

Note: People with a lower metabolic rate might find their productivity sweet spot at warmer temperatures. 

What’s the ideal indoor climate for sleep and rest? 

Cool air supports deeper, more restorative sleep. The reason is that it allows your core body temperature to drop, signalling to your brain it’s time to rest. The best temperatures to sleep at vary depending on your age; for adults somewhere around 17–18 °C is best, babies & young children should rest between 18–20 °C, whereas older adults might benefit from even warmer between 19–21 °C.  Additionally, CO₂ levels below 1,000 or ideally 600, and humidity between 40–50% will ensure you wake up feeling well rested.

💡 Tip from Birdie: “Cool room, warm bed.” A chillier room isn’t a sentence to a bad night's sleep, a cosy blanket or warm pyjamas won’t get in the way of unlocking the benefits of a cooler sleeping temperature. 

Are there some lesser known or uncommon ways your indoor climate can be affected?

Everyday products you use in your home can also shape how good your indoor climate is. Studies show that cleaning sprays, air fresheners, candles, and certain types of paints or adhesive release tiny particles and gases that can irritate your lungs over time, especially when your space isn’t ventilated.

💡 Tip from Birdie: When cleaning, open windows to let fresh air circulate, especially if you’re using stronger chemical products. Not every cleaning job needs harsh chemicals though, often warm water and a microfibre cloth, or a little natural soap, work just as well. And if you love a nice scent at home, try natural diffusers or essential oils instead of synthetic sprays or candles which are harsher on your lungs.