Signs of poor indoor air quality in a UAE home, and what the readings mean

What causes poor indoor air in a UAE home

The US EPA says the main cause of indoor air problems in homes is sources inside the home that release gases or particles. Poor ventilation makes it worse, because not enough outdoor air comes in to dilute them. The EPA adds that high temperature and humidity can raise the levels of some pollutants.

That fits how most of us live in the UAE. For much of the year, homes stay closed with the AC on. The usual indoor sources are:

• Bakhoor, oud and incense. A study of two UAE incense types burned in a room-sized chamber recorded peak particle levels of 1.42 mg/m³ (1,420 µg/m³) plus carbon monoxide, nitrogen oxides and formaldehyde. The charcoal was the main source of the carbon monoxide and nitrogen oxides.
• Cooking, especially frying and grilling, and gas hobs in villas.
• Cleaning sprays, air fresheners, perfumes and paint. The EPA lists paints, cleaning, disinfecting and cosmetic products as sources of volatile organic compounds (VOCs).
• New furniture, flooring and renovation work.
• Damp. Condensation and leaks feed mold and dust mites, which is common in coastal flats in Dubai Marina, JBR and the Palm.
• Outdoor dust that finds its way in through gaps and on shoes.

The signs you can notice without a monitor

The EPA lists the signs that a home may not have enough ventilation: condensation on windows or walls, smelly or stuffy air, dirty air cooling equipment, and areas where books, shoes or other items go moldy.

In UAE homes, we would add a few more you can check today:

• The air feels heavy or stale, most of all in a bedroom first thing in the morning.
• Smells hang around. Cooking, bakhoor or a musty smell is still there hours later.
• Dust builds up within a day or two with the windows shut, or collects around AC grilles.
• Black spots appear on silicone, ceilings, behind wardrobes or on leather.
• The AC smells when it starts. Our guide to a musty smell from the AC covers that one.

The EPA suggests a simple smell test. Step outside for a few minutes, then walk back in and notice whether any odours stand out. Your nose gets used to a smell after a while, so this resets it.

Symptoms that can point to the air at home

The EPA says the short term effects of indoor air pollutants include irritation of the eyes, nose and throat, headaches, dizziness and fatigue. For VOCs, its list also includes nausea and allergic skin reactions.

These symptoms are much like a cold or an allergy, so the EPA advises paying attention to the time and place they happen. If they fade when you are away from home and come back when you return, look for a source indoors.

One gas needs special care. The CDC says carbon monoxide (CO) has no smell or colour, and its most common symptoms are headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion, often described as flu-like. People who are asleep can be harmed before they notice anything. If you have gas cooking, a gas water heater or burn charcoal for bakhoor, the CDC advises a battery-operated or battery back-up CO alarm near every sleeping area.

This guide is not medical advice. If symptoms are strong, sudden or affect several people at once, leave the room, get fresh air and seek medical help.

What a monitor measures, and what the numbers mean

A home air quality monitor turns guesswork into numbers. Most show some or all of the readings below. Here is what each one tells you and the reference point we use.

Fine particles (PM2.5)

The WHO 2021 air quality guidelines set a PM2.5 guideline of 15 µg/m³ as a 24 hour value and 5 µg/m³ as a yearly average. The WHO says these guidelines apply to both outdoor and indoor environments. In the UAE, indoor PM2.5 usually rises with outdoor dust, frying and burning bakhoor or candles.

Carbon dioxide (CO2)

CO2 is mostly a sign of how fresh the air is, not a poison at home levels. ASHRAE’s 2025 position document says indoor CO2 does not give an overall measure of indoor air quality, but it is useful as an indicator of ventilation. It notes that many national guidelines sit around 1,000 ppm, and that levels above 1,000 ppm have been linked with more self-reported symptoms such as headaches and with lower performance in some studies, though the evidence is mixed.

A closed bedroom with two people and the AC on recirculation is the classic case. If CO2 climbs steadily overnight, the room is getting little fresh air.

VOCs

The EPA says many VOCs are consistently higher indoors than outdoors, up to ten times higher, and that there are no federally enforceable VOC standards for homes. Low-cost TVOC sensors are best used to spot changes: a jump after spraying, cleaning or burning bakhoor tells you what is driving it.

What to do if the signs point to poor air

Start with the cheapest fixes and the sources you control. The EPA says the most effective way to improve indoor air is usually to remove a source or cut its emissions, and that it often costs less than extra ventilation.

1. Remove or reduce the source. Burn bakhoor less often, in a smaller amount or in a ventilated room, and keep it out of bedrooms at night. Use the cooker hood when cooking. Swap sprays for wipes where you can.
2. Ventilate on purpose. Run bathroom and kitchen extract fans. Air the home when the outdoor air is clean and not humid. Our guide on when opening windows helps explains how to check.
3. Look after the AC. Clean the filters on schedule, and keep the drip pans clean and drain lines flowing, as the EPA advises.
4. Control damp. Keep humidity below 60%. In damp rooms a dehumidifier helps, and our guide to choosing a dehumidifier shows how to size one.
5. Filter particles. A HEPA air purifier sized for the room lowers PM2.5 from dust and smoke. It does not lower CO2 or fix damp.

MedicAir air purifiers combine a HEPA filter, an activated carbon layer and UV-C enclosed inside the unit. Like any air purifier, they are for particles and are no substitute for fresh air or removing a source.

When to get the air in your home tested

A one-off reading can mislead, because indoor air changes with cooking, sleep, cleaning and the weather outside. A proper check logs the air for days, in the rooms you use most.

It is worth getting professional help when:

• symptoms ease away from home and you cannot find the cause;
• there is a musty smell but no visible mold;
• you have just renovated, moved in or bought a lot of new furniture;
• someone at home has asthma, allergies or a new baby is on the way.

HawaQ runs a two-week indoor air quality test with professional monitors and an HVAC inspection, logging PM2.5, PM10, CO2, TVOC, formaldehyde, temperature and humidity. For ongoing tracking, there is also indoor air quality monitoring.

Disclosure: HawaQ, the indoor air quality team behind this site, supplies Stadler Form dehumidifiers and MedicAir air purifiers in the UAE. How we recommend.

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