Numerous studies have shown that indoor environmental quality (IEQ) plays a significant role in occupant satisfaction in office buildings, yet insufficient research has been done on how IEQ factors affect customer ratings of hotels and serviced apartments. This study analyzed 543,213 guest reviews from 1,397 Australian hotels and serviced apartments with 2-5 stars on Booking.com using web-mining, natural language processing, and the Three-Factor Theory of customer satisfaction. The sentiment polarities for nine IEQ factors were calculated to estimate the IEQ satisfaction. The Three-Factor Theory and mixed effects models were applied to model the asymmetric effects of IEQ factors on guests’ rating scores. All IEQ factors except for exterior view were considered Basic Factors of customer satisfaction, meaning that customers expect satisfactory performance of these factors. Exterior view served as an Excitement Factor in accommodations with 3 stars and lower, a Performance Factor in those with 4 stars, and a Basic Factor in 5-star guest homes. When IEQ performance was deemed satisfactory, the most influential factors in determining overall satisfaction were exterior view, cleanliness and maintenance, and acoustics. When IEQ performance was unsatisfactory, the most influential IEQ factors were cleanliness and maintenance, indoor air quality, and acoustics.