Soon, a seemingly small greenhouse was built next to the Yangxin Hall.
Naturally, this matter could not be hidden from Zhu Yuanzhang.
But when Zhu Yuanzhang asked about Zhu Biao, Zhu Biao just said mysteriously that he wanted to give his father a surprise.
So Zhu Yuanzhang gave up the idea of asking in detail.
Anyway, it's just a small hall on the left and right, and it doesn't cost much money.
Since it was Zhu Biao's heart, Zhu Yuanzhang went with him.
When building a house in the palace, it is natural to meet various specifications and regulations.
Fortunately, during the Hongwu period, there were not too many red tapes.
After all, the dynasty had just been established, and when Zhu Yuanzhang built the Forbidden City, he only followed simplicity and practicality.
If he really cared about the majesty of the Tian family, Zhu Yuanzhang would not open a vegetable garden in the palace.
However, despite this, compared to working in Hu Changan's house, working in the palace still has to follow a lot of rules.
Every brick and every tile must be perfect.
In short, it’s just as good as it gets.
This was the first time for Sun Yi and others to come into contact with a project with such high specifications.
Fortunately, in the end, the greenhouse was built.
Zhu Biao tried it and was extremely satisfied.
On this day, Zhu Biao diligently pulled Zhu Yuanzhang to the greenhouse.
In the Forbidden City, which is almost entirely made of wood, this greenhouse made of brick and stone seems a bit out of place.
Of course, Zhu Yuanzhang did not have too many expectations for this.
After all, Zhu Biao has never shown any talent in construction before.
And this is a masonry house.
In fact, the ancients have always had some prejudice against brick and stone houses, believing that they are not as beautiful and practical as wooden houses.
Therefore, Zhu Yuanzhang felt that this small room was definitely not as good as his palace.
But this was Zhu Biao's filial piety after all, so Zhu Yuanzhang made up his mind that no matter how poorly built the house was, he would praise it without conscience.
Under Zhu Biao's attentive greeting, Zhu Yuanzhang slowly opened the door.
However, with this casual push, he was stunned.
This small interior is as warm as spring!
It's early winter now, and the wind outside is blowing on me, bringing with it a biting chill.
But the biting chill in this room actually disappeared without a trace!
In a daze, Zhu Yuanzhang even thought that he had traveled directly from winter to spring.
Seeing Zhu Yuanzhang's stunned expression, Zhu Biao couldn't help but smile and explain: "Father, this is the surprise I have prepared for you."
"This thing is called a greenhouse. If you stay here in winter, you won't get any cold wind at all!"
"I saw that your Yangxin Hall was cold in winter, so I took it upon myself to build this greenhouse for you. I hope you like it."
Zhu Yuanzhang felt warm in his heart when he saw this.
This gift is really in line with his wishes.
Every winter before, Zhu Yuanzhang would criticize memorials in the Yangxin Hall until his hands and feet were cold.
After all, the Yangxin Hall is so big that it needs at least dozens of stoves to keep it warm.
Although it doesn't matter if you burn the stove for a day, if you burn so many stoves every day in winter, it will be a big expense.
As an emperor, even though Zhu Yuanzhang was rich all over the world, he was still reluctant to bear the astronomical heating bills.
When he thought that there were still people dying of freezing and starvation in Yingtian City, Zhu Yuanzhang really couldn't say this.
Therefore, Zhu Yuanzhang could only resist forcefully every winter.
Sometimes it was so cold in winter that Zhu Yuanzhang would even get frostbite on his hands.
Zhu Yuanzhang never mentioned these little things to anyone.
Unexpectedly, Zhu Biao, a filial child, could see his father's difficulties first and quietly help him solve the problem!
When Zhu Yuanzhang saw this, he was also extremely moved.
However, while Zhu Yuanzhang was moved, he had to ask one thing: "Biao'er, I wonder how much fuel this greenhouse consumes in a day?"
Although Zhu Yuanzhang felt that the greenhouse was indeed very comfortable to use, if the amount of fuel consumed by the greenhouse was too large, Zhu Yuanzhang would never use it.
In Zhu Yuanzhang's opinion, the fuel used in this greenhouse must be an astronomical figure!
After all, even if you only warm one Heart-nurturing Hall, the amount of fuel required every day is an astronomical amount, let alone warming an entire small building?
Zhu Yuanzhang really didn't dare to think about it.
As a civilian emperor, he was used to being thrifty all his life, but he did not want to be arrogant and extravagant when he was old.
When Zhu Biao saw this, he also smiled and said: "Father, this greenhouse was invented by Hu Changan and Hu Aiqing. I brought him here specially today. If you have any questions, you can ask him."
With that said, Zhu Biao called Hu Changan, who was waiting outside, into the room.
In fact, Zhu Biao had already expected that Zhu Yuanzhang would ask this question.
As a son, Zhu Biao is naturally very familiar with his old father's thrifty temperament.
Zhu Yuanzhang could think of these problems, and Zhu Biao could naturally think of them too.
Before building the greenhouse, Zhu Biao specifically asked Hu Changan about this matter.
After receiving Hu Changan's affirmative reply, Zhu Biao dared to start construction without hesitation.
Precisely because he knew that Zhu Yuanzhang would definitely ask this question, Zhu Biao specially called Hu Changan over today.
After all, only the inventor can answer these questions in the most comprehensive, complete and convincing way.
Although Zhu Biao had heard some things, he could not perfectly repeat some of the strange knowledge.
Zhu Biao didn't want the greenhouse he had worked so hard to build to be abandoned by Zhu Yuanzhang.
Soon, Hu Changan was brought indoors by the guards.
Zhu Yuanzhang looked at Hu Changan and was filled with emotions.
I didn’t expect that this good thing was invented by this kid!
I don’t know how this kid’s head grew and how it could hold so many fantastic ideas.
Facing outsiders, Zhu Yuanzhang put away his friendly face when facing Zhu Biao, and just asked Hu Changan calmly: "Master Hu, I wonder how much fuel this greenhouse consumes every day?"
When Hu Changan heard this, he also smiled slightly and replied calmly: "Your Majesty, if you burn charcoal in this greenhouse, you only need 5 kilograms of charcoal per day."
In order to facilitate Zhu Yuanzhang's understanding, Hu Changan specifically used the unit of measurement charcoal.
After all, briquettes have not yet been promoted on a large scale. From the nobles in the palace to the common people on the streets, everyone is still using charcoal.
What Hu Changan said is still a slightly conservative figure.
If this greenhouse were to use briquettes instead, the amount of briquettes consumed every day would be even less.
What?
Zhu Yuanzhang was completely shocked after hearing what Hu Changan said.
How is this possible when only 5 pounds of charcoal is used every day?
Even though Zhu Yuanzhang was extremely frugal before, he still used 10 kilograms of charcoal every day!
Even if he uses 10 pounds of charcoal every day, Zhu Yuanzhang still doesn't feel warm at all.