| Scenario | Temp (°C) | RH (%) | Ventilation | Carpet | Plants | Expected Risk |
|---|---|---|---|---|---|---|
| Dry, well-aired potting room | 22 | 42 | High | No | 2 | Low |
| Humid greenhouse corner | 27 | 70 | Low | Yes | 10 | Very High |
| Indoor grow tent with fan | 25 | 55 | Medium | No | 6 | Moderate |
This calculator outputs a Dust Mite Risk Index from 0 to 100.
HumidityScore = clamp(((RH − 40) / 30) × 60, 0, 60)
TemperatureScore = clamp(40 × (1 − |Temp − 25| / 10), 0, 40)
RiskIndex = clamp(Base × Multiplier, 0, 100)
- HumidityScore rises quickly above 40% RH and caps near 70% RH.
- TemperatureScore peaks near 25°C and tapers outside a comfort band.
- Multiplier adjusts for textiles, ventilation, carpeting, pets, plants, and dehumidification.
- Measure air temperature and humidity with a hygrometer.
- Select ventilation and cleaning habits that match your space.
- Include fabrics, rugs, pets, and plant count for realism.
- Press Calculate Risk Index to see the result above.
- Download CSV or PDF to track changes over time.
For allergy concerns, use this tool as guidance and consult a professional when symptoms persist.
Why dust mites matter in garden-adjacent spaces
Potting sheds, sunrooms, and indoor grow areas often combine warm air, stored textiles, and frequent watering. These conditions can support dust mites, which feed on shed skin cells and thrive in damp fabrics. A risk index helps you spot when daily gardening habits are pushing indoor moisture into the mite-friendly zone. Use it to protect indoor comfort and sensitive airways.
Humidity hotspots created by watering and storage
Watering cans, open soil bags, and drying trays release moisture for hours, especially in small rooms. If relative humidity stays above 55%, mites survive longer and allergens accumulate faster. Look for hotspots near floor-level shelves, behind curtains, and around stacked pots. Sealing compost, drying wet gloves, and venting after watering can reduce humidity without changing your planting schedule.
Temperature effects across seasons and equipment
Dust mites do best at common indoor temperatures, so heaters, heat mats, and enclosed grow tents can unintentionally boost risk. Cooler winter air can still become risky if heating drives indoor comfort while humidity remains high. Track temperature alongside humidity rather than guessing by feel. A stable 20–27°C paired with elevated humidity typically produces the highest index values.
Textiles, carpeting, and pet bedding as reservoirs
Cushions on garden benches, rugs under worktables, and pet beds in utility rooms trap dust and hold moisture. These materials act as reservoirs where mites and allergens persist even when air measurements improve. Frequent hot washing, thorough drying, and washable covers reduce buildup. If carpets cannot be removed, focus on vacuuming with filtration and keeping humidity controlled.
Turning your results into practical controls
Use the category and action checklist to choose improvements. Start with moisture: increase airflow, run a dehumidifier during humid spells, and fix damp storage habits. Then address reservoirs by laundering textiles weekly and minimizing fabric clutter. Recalculate after changes to confirm progress. Over time, exported CSV and PDF records help you identify patterns tied to seasons and watering routines.
What does the risk index represent?
It is a 0–100 score that combines humidity and temperature, then adjusts for fabrics and habits. Higher values suggest better survival conditions for mites and higher potential allergen buildup.
Which input matters most?
Relative humidity usually drives the largest change. When RH stays above about 55%, risk rises quickly, even if temperature is moderate and ventilation seems acceptable.
Can a greenhouse have low risk?
Yes. Strong ventilation, avoiding wet fabric storage, and keeping RH nearer 40–50% can reduce risk. Fans and short venting cycles after watering often make a measurable difference.
How often should I recalculate?
Recalculate after seasonal shifts, major watering changes, or new equipment like heaters. Weekly checks are helpful during monsoon or rainy periods when indoor humidity fluctuates most.
Does washing textiles really help?
Regular laundering reduces reservoirs where mites and allergens persist. Weekly washing and complete drying of cushions, covers, and pet bedding typically lowers category levels over time.
Is this a medical diagnostic tool?
No. It is an environmental guidance tool for managing indoor moisture and textiles. If you have persistent symptoms, consult a qualified healthcare professional for individualized advice.