*3.5. Basic Assumptions*

(1) Principal Component Analysis

Perform principal component analysis and select the maximum variance orthogonal method for rotation, as shown in Tables 4 and 5. For the five principal components extracted from Table 4, the cumulative variance contribution rate reached 73.796%, and the contribution rate of variable explanation was greater than 70%, indicating that the original data can be fully reflected; Table 5 revealed the indicators and proportions of the major components.

**Table 4.** Subjective evaluation and principal component analysis of hotel room types with different decoration styles.


**Table 5.** Index and proportion of each component after rotation.



#### **Table 5.** *Cont.*

(2) Data analysis

This time, single factor analysis of variance, independent sample *t*-test, and custom table analysis were performed on the collected scores of three types of decoration styles: modern simple style, British pastoral style, and modern Japanese style, to study the following issues:

First: Whether the subjective evaluation of the hotel's different decoration styles is significantly affected by the factors set in this questionnaire.

Second: Based on the IEQ theory to explore the most important factors affecting the subjective evaluation of guests in hotel room types with different decoration styles.

Third: The factors that have a greater impact on the judgment factors of the guests' subjective evaluation of most hotel room types.

 1 Single Factor ANOVA

The single factor ANOVA study was used to determine the significant impact of different hotel decoration styles on the subjective evaluation of the guests. The results were shown in Table 6:

**Table 6.** Results of single factor ANOVA on the rating of hotel 3 decoration style by various influencing factors.


From the results shown in the above table, it can be seen that different factors have a significant impact on the scores of different styles of room types.

 2 Independent Sample *t*-test

The test was mainly carried out by taking the average of all relevant factors and constructing a new dimension (for example, using the average of the overall scores of the four factors that measure air quality to form a test variable and named it the air dimension); The test value was subjected to an independent sample test to verify whether the new five dimensions were significantly different from the test value.

Then, the average score of the overall situation of each room type of the hotel decoration style was used as the test value, the average score of the indoor environment of each room type of decoration style was used as the test variable, and an independent sample test was carried out to determine whether the hotel's indoor environment score was significantly different from the hotel's overall score.

The structural relationship between variables, T value, and hypothesis test results were shown in Table 7. All hypotheses had passed the *t*-test, and the path coefficients supported the hypothesis at the level of confidence α = 0.005.


**Table 7.** Hypothesis test results.

It was further verified that the five dimensions of the IEQ theory had a significant impact on the subjective evaluation of customers.

 3 Custom Table

In addition, the author used a custom table to further verify the factors that had a greater impact on the different decoration styles of the hotel. The analysis results were shown in Figure 9 below:

**Figure 9.** The influence of four factors on the subjective evaluation of three decoration styles.

The subjective scores of customers in modern simple style rooms were mainly affected by light environment and non-light visual factors, which were in line with the hypothesis. The factors of light environment and air quality played an important role in the subjective ratings of customers of British pastoral-style rooms, which were in line with the hypothesis; the subjective scores of customers of British pastoral-style rooms were greatly affected by non-light visual factors, which was attributed to the British pastoral style, showing the characteristics of the pastoral atmosphere through decoration, and paid more attention to non-light visual factors to create a natural space that met customer expectations. For modern Japanese-style hotel room types, light and the thermal environment were the core influencing factors of customers' subjective ratings, which was in line with the hypothesis; the results showed that the subjective ratings of modern Japanese-style hotel room types were also greatly affected by non-light visual factors, mainly due to modern Japanese style was mainly created by non-light visual factors such as decoration atmosphere and home decoration such as tatami.

#### **4. Discussion**

#### *4.1. Research Innovation*

The innovation of this study is that starting from the hotel indoor environment, according to the IEQ definition of indoor environmental quality by the National Institute of Occupational Safety and Health, the hotel indoor environment is subdivided into acoustic, light, thermal, air quality, and non-light visual factors five dimensions to explore the impact of each dimension on the subjective evaluation of customers, innovating in subdivision angle. Furthermore, this study takes room types with different decoration styles of hotels as the research object and explores the similarities and differences in customers' subjective evaluations of hotels with different decoration styles. The study found that the influencing factors of the indoor environment of three different decoration styles were different. Existing studies have not incorporated the hotel's decoration style into the influencing factors of customers' subjective evaluation, which is another innovation of this study. The study also found that for the same hotel with different decoration styles, the factors that mainly affect the subjective evaluation of its customers are not the same. The study further found that the hotel's indoor environment plays a key role in influencing the subjective evaluation of customers. In particular, the five aspects of acoustic, light, thermal, air quality, and non-light visual factors have a great impact on the comprehensive psychological and physiological impact of the occupants, thus affecting the subjective evaluation of the hotel by customers.

#### *4.2. Comparison of Similar Studies*

At present, many studies on hotel customer satisfaction have found that hotel indoor environments can have an impact on customer satisfaction by mining online review texts [20,47,48].

Through this research, we deeply explored the influence of the hotel indoor environment on customers' subjective evaluation and found that the hotel indoor environment has a positive impact on customers' subjective evaluation. The test shows that all the hypotheses H1–H9 have passed the *t*-test, and the path coefficient is significant in the confidence level α = 0.001 level, which further verifies the significant influence of the hotel indoor environment on customers' subjective evaluation, which is consistent with previous research conclusions.

This study uses the method of case study, selects a hotel with different decoration styles as the research object, and collects the subjective evaluation data of customers through questionnaires. The case study method can provide a real environment for us to collect relevant data. Based on the real environment, we can explore our research problems more deeply. However, the case study should also consider the particularity of the selected case hotel. Recently, some studies have selected specific hotels as research objects to explore issues related to customer satisfaction, such as selecting international hotels in Pyongyang to explore customer satisfaction under the condition of limited choice [49]. Case studies can make the problem more in-depth, but there are still limitations in case selection and conclusion promotion. In future research, multiple case hotels can be selected for the investigation to increase the universality of the research conclusions [26]. In addition, in terms of exploring customers' subjective evaluation of the hotel, many studies have adopted the method of online review analysis, which can make up for the lack of representativeness of case study data to a certain extent.

#### *4.3. Significance*

Modern people spend most of their time working and living indoors [21], and customers' perception of the overall value of the hotel is mostly derived from the status quo of the hotel's indoor environment. To improve the driving factors of customer satisfaction and thus improve the subjective evaluation of customers for the hotel, the major decoration styles of the hotel should ensure that the acoustic, light, thermal, air quality, and non-light visual factors of the indoor environment are higher than the hotel standards. For modern simple style rooms, more attention should be paid to their light and non-light visual factors. The British pastoral-style rooms should pay more attention to the influence of light environment, air quality, and non-light visual factors; the modern Japanese-style rooms should focus on creating their light, heat, and non-light visual environment. In addition, the individual needs of customers cannot be ignored, to provide customers with personalized services.

#### *4.4. Limitations and Future Work*

This study investigates the customer satisfaction evaluation of the indoor environment quality of Shiyu Hotel in Guangdong Province, adopting the method of text analysis combined with questionnaires. However, there are still shortcomings in this study that need to be improved.

The object of this study (Shi Yu Hotel) has seven major decoration styles, including modern simple, industrial, Japanese, and pastoral. However, to control the decoration style as the only variable, the hotel room type is finally reduced to three mainstream decoration styles: modern simple, British pastoral, and modern Japanese. The research results cannot fully represent various decoration styles of hotel room types.

Among the samples used for data analysis in this questionnaire survey, due to the different preferences of customers' hotel room styles, there is a large difference in the number of samples collected for the three hotel room styles in this study. This problem will also have a certain impact on the data analysis results to a certain extent.

This survey mainly focuses on the acoustic, light, thermal, air quality, and non-light visual factors stipulated by IEQ. It is a shortcoming of this study not to consider the subdivided influencing factors such as material type, texture, color, pattern, decorative element, and plant form in non-optical visual factors.

In future research, it is possible to expand the research on different hotels, room types with different decoration styles, and groups of different ages and occupations, so that the conclusion can more comprehensively determine the factors of different decoration styles and different hotels that affect the subjective evaluation of different guests and the importance of different factors affecting the subjective evaluation of guests in different hotel decoration styles. To establish the subjective evaluation system of the hotel indoor environment suitable for the hotel's multi-decoration style room type and expand the scope of application of the research conclusions, and can deeply study the impact of the subdivision factors of these five major influencing factors on the subjective evaluation of guests.

#### **5. Conclusions and Suggestions**

#### *5.1. Conclusions*

This research combines the text analysis method and questionnaire survey method, using KH Coder and SPSS to process and analyze the data. It also studies the influence of hotel indoor environment on customers' subjective evaluation, and draws the following conclusions:

(a) The light environment and non-light visual factors in the indoor environment of different decoration styles of the hotel are the key factors affecting the subjective evaluation of customers' indoor environment, and their impact is the largest and most obvious.

The light environment and non-light visual factors have a great influence on the subjective evaluation of customers in each decoration style room type, and the average satisfaction score is high, indicating that the respondents are relatively satisfied with the light conditions and non-light visual conditions of the Shiyu Hotel in Guangdong Province, which should continue.

(b) For the hotel's modern simple style room type's indoor environment, the light environment and non-light visual factors have a greater impact on the subjective evaluation of customers and are the most important.

From the hypothesis test t-values of H6a and H6b, 1.232 and −3.132, and the two-tailed probability *p*-values of the *t*-test are 0.219 and 0.315, respectively, which are greater than 0.05 of the significance level α. From the results of the hypothesis, it can be seen that the light environment and non-light visual factors are the main factors affecting the customer's satisfaction rating of the hotel's modern simple style room type. In addition, from the result data in Figure 9, it can be further verified that the light environment and non-light visual factors have an important influence on the customer satisfaction score of the hotel's modern simple style room type, and the non-light visual factors have an influence of up to 40%.

(c) Light environment, air quality, and non-light visual factors play a central role in the subjective evaluation of the indoor environment of the British pastoral style room type, and have a greater impact on it.

For the British pastoral style room type, it can be concluded from the test results in Table 7 that the assumptions H7a and H7b are established, that is, the light environment and air quality have a greater impact on customer satisfaction with the hotel British pastoral style room type. From Figure 9, visibly light environment and air quality have an important impact on customer satisfaction with the British pastoral style of the hotel, which is as high as 60% and 33.7%, respectively. At the same time, from Figure 9, it can be concluded that non-light visual factors have a great influence on the score of British pastoral-style room type, reaching 31%, which is consistent with the existing research results.

(d) The hotel's modern Japanese-style room type is significantly affected by the light environment, thermal environment, and non-light visual factors. This decoration style is also the most sensitive to light, heat, and non-light visual factors.

From the test result data in Table 7, it can be concluded that the H8a and H8b hypotheses are true, that is, the light environment and thermal environment are the most sensitive factors in the customer's satisfaction score for the hotel's modern Japanese-style room type, which are the most sensitive factors affecting the score. At the same time, from the result data in Figure 9, it can be further verified that the light environment and thermal environment have an important influence on the customer satisfaction score of the hotel's modern Japanese-style room type, and the thermal environment influence is as high as 37.7%. However, for modern Japanese-style hotels, there is no cliff-like distinction between the influences of various factors, but compared with other factors, the light and thermal environment have a greater impact on the subjective ratings of modern Japanese-style hotel customers to a certain extent.

(e) To sum up, the factors included in the five IEQ theories of indoor acoustic, light, thermal, air quality, and non-light visual factors have the greatest impact on customers' subjective evaluation of the hotel's indoor environment.

On the whole, the observed value of each F statistic in the results of single factor ANOVA is greater than 1, and the corresponding probability *p*-values is approximately 0. It is believed that the different levels of influencing factors have a significant impact on the

score of each decoration style hotel. Additionally, the *p*-values of the results of hypothesis testing H1, H2, H3, H4, and H5 are 0.974, 0.219, 0.475, 0.100, and 0.202, respectively. The path coefficient supports the hypothesis at the level of confidence α = 0.005; it is further demonstrated that the hotel studied in this paper is established. The five dimensions of the indoor environment are the main factors that affect the subjective evaluation of customers.

The research further shows that among the five factors that affect the subjective evaluation of customers, the importance of each factor is ranked as follows: light and non-light visual factors are the most important, followed by thermal environment, air quality, and finally the acoustic environment.

#### *5.2. Suggestions*

On this basis, we put forward the following suggestions to the hotel: each type of decoration style of the hotel should ensure that the acoustic, light, thermal, air quality, and non-light visual factors of the indoor environment are all higher than the hotel standard; for modern simple style rooms, more attention should be paid to the influence of light and non-light visual factors; the British pastoral-style rooms should pay more attention to the influence of light environment, air quality and non-light visual factors; the modern Japanese-style rooms should focus on creating its light, thermal and non-light visual environment. In addition, the individual needs of customers cannot be ignored, to provide customers with personalized services.

 1 Modern simple style hotels should strengthen lighting design and space design.

Light environment and non-light visual factors are the most important factors in the subjective evaluation of modern simple style hotels; for modern simple style hotels, highquality lighting design can create a comfortable lighting environment and meet people's visual needs. In the process of lighting design, especially with the continuous development of LED technology, LED lighting products continue to emerge. The modern simple style hotels' lighting design can use more LED lighting products to improve the quality of the light environment and meet the health, energy saving, and cost reduction. In addition, modern simple style hotels can improve the quality of non-light visual elements of hotels by arranging vegetation that complements each other, focusing on decoration color matching, and matching furniture with high decorative texture.

 2 British pastoral-style hotels should strengthen the HVAC system.

The above conclusions show that the light environment, air quality, and non-light visual factors play a central role in the subjective evaluation of the British pastoral-style hotel, and have a greater impact; in addition to improving the lighting design space design, indoor air quality deserves attention, it is a very complex indicator, various time-dependent physical and chemical parameters are components of indoor air quality, which are in turn affected by outdoor conditions (climate), building conditions (materials, structure, and construction), the hotel's HVAC system (heating, ventilation, and air conditioning) systems), interior space arrangement (furniture, furniture, equipment), and the impact of occupant productivity patterns [50]. At this stage, many hotels have not done a good job of building ventilation to save costs. The indoor ventilation is completely carried out by air conditioners. The occupants often smell a musty smell when they enter the room, which will not only affect the occupancy experience of the occupants and the subjective evaluation of the straight line. It will also cause hidden dangers to the health of the guests. For the British pastoral style, it is very important to strengthen the HVAC system of the hotel: let the indoor air quality meet the standard, improve the occupant's check-in experience, strengthen the health protection, and finally maximize the subjective evaluation of the occupants

 3 Modern Japanese-style hotels should improve heat and humidity treatment capabilities.

Through investigation, it is found that hotel guests are very sensitive to the thermal environment in modern Japanese-style hotels; therefore, for modern Japanese-style hotels: how to dehumidify and maintain the ideal thermal environment of the hotel is very important, such as ventilation and dehumidification, heating and dehumidification, Dew

point dehumidification, rotary dehumidification, membrane dehumidification, solution dehumidification, and other common dehumidification methods.

**Author Contributions:** Supervision and revision, J.X., M.L. and D.H.; investigation, D.H., Y.W. and S.Z.; resources, Y.W.; draft, D.H., Y.W. and S.Z.; proofreading and editing, D.H., Y.W. and S.Z.; data analysis, D.H.; text analysis, Y.W.; methodology, Y.W.; visualization, D.H. and Y.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was part of the project called "The study on rural tourism revitalization planning and sustainable living coordination mechanism" funded by the International Cooperation Open Project of State Key Laboratory of Subtropical Building Science, South China University of Technology, the funding number is 2019ZA02; China youth fund of national natural science foundation projects "Research on visual landscape evaluation method of traditional villages in Guangdong based on deep learning", the funding number is 52208057 ; And "Guangzhou philosophy and social science planning project: Research on Guangzhou Higher Education Reform Promoting the coordinated development of Guangdong Hong Kong Macao Greater Bay Area", the funding number is 2022GZGJ131.

**Acknowledgments:** We would especially like to thank Jian Xu Muchun Li and Zhicai Wu, for their assistance in proofreading the manuscript, and the International Cooperation Open Project of State Key Laboratory of Subtropical Building Science, South China University of Technology.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **Appendix A**

Questionnaire on investigation on actual customer satisfaction of different decoration style hotel indoor environment. (This questionnaire is used to present the investigation process and facilitate readers' understanding).

**Dear friends: this questionnaire is mainly to understand the actual satisfaction of different decoration style hotel indoor environment. Please recall your last experience of HOTEL and fill in the questionnaire. This questionnaire is filled in anonymously, and the questionnaire information is only for academic research. Thank you very much for your support!**

Have you ever stayed in a HOTEL (single choice) \*

yes

 no (please skip to the end of the questionnaire and submit the answer sheet) HOTEL city: (fill in the blank) \*
