Hello everyone, I am K-uncle who’s anxiously waiting for RisingAuto R7 to be released. Today I unexpectedly got a chance to test RisingAuto R7’s panoramic sunroof (commonly known as glass roof) performance under the scorching summer sun. At the end of the article, I will also share some cooling tips. The article is over 2600 words long. Please enjoy reading it patiently and thank you in advance!
On August 5, 2022, the news reported that Shanghai had a temperature of 51℃. I can’t help but laugh, even though it was a misunderstanding, the actual temperature in Jiading was still as high as 38.5℃. It felt like the ground was scorching hot when I walked outside. In the morning, I went to Xiaomi’s flagship store with friends and bought some smart home accessories. During lunchtime when we were about to park and grab some McDonald’s, we were surprised to see a white RisingAuto R7 parked next to us.
“R7! R7! RisingAuto R7! Ooh-ooh (my monkey cry)!” I grabbed my phone and took pictures of it. My three friends silently watched me jump around and get excited.
By chance, I saw the car key on the wiper blade. Oh my god, wasn’t that the key to the R7? My mouth salivated and I reached out to grab it. Suddenly, an idea came to my mind. Previously, @R+ Wang Zixing bragged in the group chat that RisingAuto R7’s panoramic sunroof could withstand intense sunlight without causing the car interior to heat up. The product manager, Wen Qing, claimed that the “black technology” silver-plated glass roof could block 87% of heat and 99.9% of ultraviolet rays. It also had some FTO (LOW-E), PVB interlayer technology, which could cool the car in summer and warm it up in winter. Today is so hot, so I decided to test whether these were just promotional gimmicks or actual useful features. Just as I was strategizing my test methods, unfortunately, the car owner came back. It turned out he was a testing engineer. I felt embarrassed, so I took out my R7 pre-order receipt and explained my purpose. After some back and forth negotiation, we finally agreed to a transaction cost of a can of Coke for an hour of static testing time.
Let’s get started then! Today, I will conduct a small test to evaluate RisingAuto R7’s temperature control ability in intense sunlight during summer and to verify the performance of the silver-plated glass roof.
First, let me introduce the “victims” of today’s test, the private car of a friend who was inexplicably pulled into the test: SUV Xiaohui (price of 400,000 RMB), the small orange car that runs rampant in the city (price of 280,000 RMB), and the Feivan R7 (an engineering test car).
Then, let’s talk about the testing logic that I came up with temporarily: as we learned in middle school experiments, controlling variables is necessary for testing. We need to have the same temperature and location for the sun exposure test. It so happens that all three test cars have panoramic sunroofs, and the roof and interior color of the driver’s cabin are all black, eliminating the influence of the black body (color) on temperature. Based on these conditions, we can complete the entertainment version of the horizontal sunroof temperature test.
How can we get a relatively fair initial testing environment? We first completely close all the doors and windows of the cars and let the interior temperature of all the cars rise to a very high value. Then we simultaneously open the car doors and wait until the temperature inside the cars drops to nearly the same outdoor temperature of about 38.8℃. This way, the initial temperature of the three cars can be on the same starting line.
The sunroof exposure experiment can simulate a person leaving the car in an outdoor parking lot to eat and returning after 40 minutes. The experiment examines the heat insulation performance of the driving cabin temperature of the car in a hot environment.
During the sunroof exposure experiment, a Xiaomi Mijia app-connected thermometer was used to accurately read the temperature inside the car without opening the car door. The test lasted for 40 minutes, and the temperature was recorded every 10 minutes. Ultimately, the temperature changes of the three cars can be compared by plotting the results on a curve.
After the exposure, the temperatures of the following four points inside the car were recorded using a laser thermometer to simulate the temperature perception of a person who returns to their car:
Temperatures of the area in contact with the head and neck: the temperature of the headrest position
Temperatures of the surface of the backrest on the right side of the person in contact.
Temperatures of the surface of the seat cushion in contact with the sitting person.
Temperatures of the surface of the steering wheel in contact with the driver’s palms.
Finally, let’s compare the temperature difference between the inside and outside of the sunroof and see how it performs as an insulator. The experimental method is complete, and now let me introduce our “tools”:
Laser industrial thermometer X1 (kept in the trunk for work)
Xiaomi Bluetooth thermometer X3 (just purchased from Xiaomi Home)
After sweating through a series of operations, here are the test results:
First, the ground temperature of the testing environment:
### Second, Temperature Changes Inside the Cars
The temperature changes inside the cars, including Xiaobai (RisingAuto R7), Xiaohui (an SUV), and Xiaocheng (a sedan) at different times were recorded by the thermometers placed inside the cars:
Third, Temperature Feeling After Sun Exposure
The recorded temperature of Xiaohui (an SUV) at 6:00 in the car:
The recorded temperature of Xiaobai (RisingAuto R7) at 6:00 in the car:
The recorded temperature of Xiaocheng (a sedan) at 6:00 in the car:
Summary of the temperature at different positions of the cars after sun exposure:
The temperature difference between the inside and outside of the glass skylight was 9.1℃ (RisingAuto R7), 5.1℃ (Xiaocheng sedan), and 2.6℃ (Xiaohui SUV).
Conclusion and Thinking:
This test is not rigorous enough from a professional perspective and is for entertainment purposes only. However, some interesting points can still be discovered. For example, the official “silver-plated glass roof” does have some effect, claiming to block 87% of heat and 99.9% of ultraviolet rays. This is also evident in the actual temperature test, with a temperature difference of 9℃ between inside and outside, which means this transparent and black technology glass does block a lot of heat from entering the car.
The title of “MVP of the whole-field induction cooker” belongs to Xiaocheng, as it turned out that the friend’s car was still pasted with sunscreen films, but the heat insulation effect was surprisingly poor. After returning home, I consulted with the R7 WeChat group, and experienced owners explained that sunscreen and heat insulation are two different things. Some sunscreen films can only reduce the glare of sunlight but cannot block heat from entering the car.
During the test, I had some technical exchanges with many prospective owners of R7 in the group. They suggested that I spend an entire afternoon on the test. On the one hand, the time was too short, and the test did not allow me to take up too much time. The air in the SUV car space is relatively large, so the rate of heating is different from that of the sedan.On the other hand, I believe that no matter what car model is exposed to sunlight, it will reach a temperature limit, which depends on the balance between the heat entering from the outside and the car’s passive heat dissipation ability. The temperature will not increase. This state will end with the setting of the sun. No matter how high the temperature is, it can be quickly cooled down by opening the air conditioning in the APP in advance. Therefore, I chose a noon sun exposure test within an hour to simulate the actual user usage scenario. I hope this can bring some help to you all.
Finally, share some summer driving experiences:
[Suggest leaving a gap in the window], the reason why the temperature inside the car can be so much higher than outside in this sun exposure experiment is that after locking the car, the enclosed space inside the car has no air circulation and is constantly being heated by the sun. It’s like a sunshine room in a botanical garden. If there is no rain, leaving a small gap in the car window. The heated air will generally rise and flow out of the car through the gap of the window, which can significantly reduce the temperature inside the car. Of course, you should always pay attention to whether it will rain, and intelligent car users can remotely close the window on their mobile phones, as well as the issue of safety and anti-theft.
[Three steps to quickly cool down] What if the inside of the car is already hot? In the first step, we can open all the car doors to allow the hot air inside the car to quickly dissipate, making the temperature inside and outside the car the same. In the second step, with all the car doors open, we can close one side of the front and rear doors at the same time. Repeated a few times, the air inside the car can circulate quickly. In the third step, close all car doors and windows, turn on the air conditioning to the inner loop, adjust the temperature to the lowest and the wind speed to the maximum and blow the cold air upward. This benefit can quickly reduce the temperature of the head space of passengers who are more sensitive. Cold air will naturally descend, which can quickly make the car cool. As for the seats and steering wheel, which may be hot, you can prepare a small spray of pure water to spray on them to cool them down quickly, so that they will not be hot to touch.
[Safety first for summer driving] Finally, I still want to remind the smoking friends not to leave the lighter in the car, which may cause an explosion when the temperature rises after exposure. Also, do not leave food, such as melt chocolate, which will be difficult to clean on the seat, and snacks and fruits which are easily perishable.
Please note that all the test results mentioned in this article are for personal use and not official release content. Be careful to discern. Finally, I hope the FEYVAN R7 can go on the market soon, Goma!
This article is a translation by ChatGPT of a Chinese report from 42HOW. If you have any questions about it, please email bd@42how.com.