New House, Located in Changsha, with a Construction Area of 140 Square Meters and an interior Area of Around 110 Square Meters, Is it Suitable for a Water-Cooled Central Air Conditioning System Combined with Floor Heating or Should I Opt for Separate Central Air Conditioning and Radiant Floor Heating?

Currently, a newlywed couple is working nine to five, and they are planning to have a child next year They expect their parents to come and help take care of the child After some initial research, they found out that a colleagues apartment, with a floor area of 90 square meters, has a wall-mounted heater, and the winter heating cost is around 3000 yuan They are wondering if the operating cost of a water heater can be lower They also plan to seek consultation on HVAC issues and are willing to pay for the knowledge

Water dispenser recommendation.

Recommended water purifier.

I am located in Chengdu, where the weather is similar to Changsha. The area inside my house is about 200 square meters. I moved in on January 20th this year and have experienced the energy-saving benefits in winter and the comfort in summer from the water purifier. The image below shows my total electricity bill for this year. Before moving in January, I opened the windows and turned on the floor heating to remove formaldehyde. This total electricity usage includes the basic monthly consumption of 300 degrees. On the right is the separate electricity consumption recorded by the water purifier after installing the Zhuohu model on February 11th.

I have been using it for almost a year now, and based on the energy-saving features of the water purifier, I now only need to slightly adjust the temperature and turn on the floor heating or air conditioning. It is only unused during late April to mid-May and late October to early November. It is absolutely comfortable when I come back home. I have gradually learned how to optimize the settings for my own system, and the energy consumption has gradually reached its best. Below is a comparison of the energy consumption when the floor heating is turned on recently and the energy consumption in March when the temperature is similar.

Although the initial cost of the water purifier installation may be slightly higher, its comfort and energy-saving advantages are remarkable. With an area of 140 square meters, it is also suitable to install a water purifier, and I strongly recommend it. Of course, you also need to choose the main unit and indoor unit based on your specific situation, and continue to observe and adjust. I recommend reading the articles by these few well-known experts on Zhihu: @Pao Xiaozhuan, @Shushi Jiakepu Xiansheng, @Zhu Guoqing. I started and improved by reading their articles, and I would like to thank them again. With people like them sharing knowledge, Zhihu is what it is.

Why recommend dual-supply water system

First, let’s talk about the conclusion: recommending dual supply of water system (hereinafter referred to as dual supply).

Why recommend dual supply?

  1. According to the details of your question, I temporarily believe that you have a hard need for central air conditioning and floor heating throughout the house. Dual supply can just meet your needs and bring you more comfortable air conditioning cooling experience and lower and more energy-efficient floor heating energy consumption, as explained below.

1. Let’s talk about cooling first. Assuming you choose traditional central air conditioning (multi-split), you will most likely have a terrible experience in low-load usage scenarios during summer (at night or when only one or two bedroom air conditioners are in use). The specific performance is that the room temperature fluctuates between hot and cold, and the energy consumption is excessive. The specific reasons are not explained in this article, but you can refer to this article by @抛小砖.

Which is more energy-efficient and comfortable for central air conditioning, fluorine-based or water-based?

On the other hand, water-cooled air conditioning, benefiting from decoupling the refrigerant transportation from the compressor and the buffering effect of the water tank, in conjunction with excellent indoor units, will greatly improve the nighttime experience in summer. Apart from the lower energy consumption, it is unlikely that you will be awakened by the cold air from the air conditioning while sleeping at night. At the same time, the room will not be overly dehumidified (multi-split air conditioning uses fluorine as the refrigerant, with a low working temperature and a large temperature difference with the room, so it has strong dehumidification capability; while the refrigerant in dual supply water-cooled air conditioning is water, which cannot go below 0°C, and the daily temperature setting is generally 12-15, with a small temperature difference with the room, so it will not excessively dehumidify), and the relative humidity can be closer to the comfort zone of the human body.

Thanks to its unique working principle, dual supply water-cooled air conditioning is extremely friendly to the elderly and women (the water temperature can be adjusted and the air flow is gentle without being piercing).

2. Now let’s talk about heating.

① Comfort: The main advantage of traditional wall-hung boilers for heating is that they can supply domestic hot water (replacing water heaters). However, this is also a disadvantage because in the working logic of almost all wall-hung boilers, the priority of domestic water is higher than that of heating water. If during winter, the entire family takes showers during a concentrated period of time and you have a woman who loves taking baths, floor heating will lose the supply of heating water, causing a significant drop in room temperature. This problem does not exist with dual supply heating, as the main unit is only responsible for supplying heating water, while domestic hot water is provided separately by a water heater.

Furthermore, most wall-hung boiler floor heating systems operate on the principle of large temperature difference * small flow rate (wall-hung boilers need frequent opening and closing of the flow control valves to control room temperature, and when the set temperature is reached, the heating water supply to the floor heating pipes needs to be shut off, causing fluctuations in floor temperature).

On the other hand, the dual supply floor heating system operates on the principle of large flow rate * small temperature difference (the flow control valves can remain open, resulting in more stable floor temperature).

② Energy efficiency: Under the same insulation conditions and usage scenarios, it is difficult for wall-hung boiler heating to match the low costs of dual supply heating. For more details, please refer to this article by @抛小砖.

抛小砖: Lower costs than central heating! A heating report from a homeowner in the southern region

3. System recommendations

① Reasonably configure the main unit: Dual supply main units do not have the same proportion restrictions as multi-split units, so there is no need to blindly choose a larger main unit. Choosing a suitable and reasonable one should be based on considering the usage conditions, while also paying attention to issues such as direct sunlight.

② Reasonably configure the water pump: The water pump is the “heart” of the water system. Prioritize choosing a DC pump and avoid pitfalls with AC pumps.

③ The indoor unit is of vital importance to the air conditioning experience: First, I recommend the Rhino King intelligent silent indoor unit, followed by brand-name DC indoor units, and avoid pitfalls with AC fixed-frequency indoor units.

④ If space allows, try to use a larger water tank: A larger water tank can better reduce the frequency of the main unit starting and stopping in low-load scenarios.

⑤ If possible, use 20 for the floor heating pipes instead of 16: Control the length of the piping to be within 120 meters.

⑥ This article provides an example of the consequences caused by unreasonable configurations.

Why does Carrier water-cooled air conditioning consume so much electricity?


Choosing a reputable HVAC merchant is more important than the brand!!!

Choosing a reputable HVAC merchant is more important than the brand!!!

Choosing a reputable HVAC merchant is more important than the brand!!!

Lastly, thanks to @抛小砖 **for deepening the understanding of pain points in the HVAC industry and proposing effective solutions from the perspective of a homeowner. With almost single-handed effort, they have accelerated the positive development of the entire dual supply industry.

24KW wall-hung boiler aluminum dry floor heating + multi-split central air conditioning: the most cost-effective configuration for a 140-square-meter apartment in Changsha.

Building area of 140 square meters apartment in the Changsha area, with a floor heating area of ​​about 100 square meters. A newlywed couple who are office workers, no one is at home during the day. The configuration plan with the highest cost performance for air conditioning and floor heating is: a 24KW wall-mounted boiler with aluminum plate dry floor heating and a multi-split central air conditioning system. The advantage is that in the summer, the central air conditioning can be used instantly with the lowest electricity cost. In the winter, the dry floor heating can be used instantly with the lowest gas cost, making hot water for daily use most convenient!

The rustproof aluminum plate dry floor heating module is thin, only 3cm thick. The surface of the dining room and living room can be directly tiled with cement. In the rooms, the floor can be laid on top of the module with a height of 2.5cm, with a total thickness of 7.5cm. When installing, there is no need to raise the anti-theft door. The aluminum plate has good heat conduction, and there is no risk of uneven heating in the area without floor heating. Under the same water temperature, the floor temperature of the dry floor heating can be increased by 5°C compared to the normal wet floor heating. The room temperature can be increased by 3°C, providing a high level of comfort.

The aluminum plate dry floor heating heats up quickly, and the floor temperature increases after half an hour of operation. After shutdown, it can maintain heating for 4 hours. Turning off the floor heating for 12 hours during the day while at work will not affect the use at night, and it can save 50% of the gas cost compared to wet floor heating. In addition, the dry floor heating module has good heat insulation on the ground, so the heat is not transferred to the downstairs, saving about 25% of the downward heat loss compared to wet floor heating. The highest gas cost can be saved by up to 75%, estimated at the highest tiered price of 4.248 yuan per cubic meter in Changsha. The monthly gas cost for 100 square meters of floor heating can be controlled to around 500 yuan, which is similar to using air conditioning in winter. However, the monthly gas cost for wet floor heating is around 2200 yuan, so the dry floor heating is very energy-efficient.

In addition, the aluminum plate dry floor heating has good moisture-proof and shock absorption functions, protecting the floor and furniture from moisture and mold, and reducing shock and noise for the floor slabs. In the future, when children play on the floor, it will not disturb the neighbors downstairs, so it also has a high level of functionality and cost performance! Of course, if you need to further improve the comfort of air conditioning in summer, a water system central air conditioning can be used.

Ideal Configuration for a 140 square meter apartment in the south: Rust-proof aluminum-plate dry floor heating and central air conditioning.

Key phrase: Ideal Configuration (最理想的配置方案) Southern 140-square-meter salary-class apartment, the most ideal configuration is wall-hung rust-proof aluminum plate dry-type energy-saving floor heating + central air conditioning. The floor heating, air conditioning, and domestic hot water have balanced functionality. Considering that there will be children soon, tiles are used in the dining and living rooms, and laminate flooring is used in the bedrooms to facilitate children playing on the ground. If the budget allows, a central air conditioning water system with gas wall-hung boilers could be considered, making the water-cooled air conditioning system more comfortable in summer.

The thin rust-proof aluminum plate dry-type floor heating does not need to raise the anti-theft door during installation, nor does it require ground leveling. It can be installed at once before tiling. Tiles can be directly laid on the module surface in the dining and living rooms. It warms up quickly and has good effect. The floor temperature can rise in half an hour after starting up, and the heating can be maintained for 3 hours after shutting down. It warms up quickly with a moderate cooling rate, and can be used as needed. Turning off the floor heating during the day for 12 hours does not affect its use in the evening. It can save half of the energy cost and has good thermal insulation performance. The heat transfer loss to the downstairs is smaller than that of ordinary wet floor heating, reducing it by about 25%. It can save up to 75% of gas costs, and according to the price of natural gas in Changsha, the cost of floor heating in winter can be controlled within 500 yuan per month, which is similar to the cost of heating with air conditioning. It has high energy efficiency and cost-effectiveness.

The aluminum plate dry-type floor heating module has functions of insulation, moisture-proof, soundproofing, making the air conditioning cooler in summer, protecting the floor and furniture from moisture and mold, reducing floor vibration and noise, and improving the comfort of the ground. It has multiple practical functions and high cost-effectiveness. In the future, when children play on the ground, the sound will not be heard downstairs, and it will not disturb the neighbors downstairs!

Consider energy-saving, water dispenser may be more suitable. And air conditioning will provide better comfort in summer. However, hot water needs separate consideration.

Considering energy conservation, water coolers would be more appropriate. In addition, air conditioning will provide a better cooling sensation in the summer. However, hot water needs to be considered separately.

You Should Buy Hisense Hitachi + Rhinoceros King

I think everyone should buy Hisense Hitachi + Rhino King on the whole Internet

Because they have a lot of water army groups, at least 6

If you don’t buy it, you will be shamed

They will say you don’t understand air conditioning

If you don’t buy their high-end brand in the universe

They will say you joined the National Army in 1949

Separate operation: Use fully premixed condensing furnace for floor heating boiler, create secondary system.



In this project, we aim to install a floor heating system with a condensing boiler. The system will be divided into two separate parts: the boiler itself, which will utilize a fully premixed condensing burner, and the secondary system.


For the floor heating, we will be using a fully premixed condensing burner. This type of burner is highly efficient, as it pre-mixes the fuel and air before combustion, resulting in lower emissions and energy consumption.

Secondary System

The secondary system, responsible for distributing the heated water throughout the building, will be installed separately from the boiler. This separation allows for easier maintenance and troubleshooting, as well as flexibility in adjusting the water flow and temperature.

Please let me know if you have any questions or further requirements.

Water machine considerations for home installation

Originally, I only intended to write a comment and not respond, but seeing so many sellers, I feel obligated to answer as a 5-year user of water dispensers.

First, you need to understand that water dispensers are complicated systems that require technical expertise. If you expect the elderly or children to use it without any problems while you’re away for several days, you better dispel that idea. It’s difficult to explain how troublesome it can be in just one sentence.

Secondly, whether or not your house is suitable for a water dispenser depends on your flooring. In order to provide cooling through radiation, I chose full tiles (even though they are imitation wood floor tiles). If you choose wooden flooring, it is not advisable to consider a water dispenser. Although someone may tell you that there are wooden floors specifically designed for underfloor heating, these claims are not reliable. Especially if you have some rooms with wooden flooring and some with tiles, you should not consider a water dispenser, as it can easily result in uneven heating. The reason is simple: a heat pump transfers heat from the outdoors, and the greater the temperature difference, the lower the efficiency. With wooden flooring, higher water temperatures are required, whereas my fully tiled house can be heated with water temperatures as low as 30 degrees Celsius, and even lower throughout the day (although it can’t be set too low due to defrosting reasons). It is estimated that wooden flooring would require water temperatures of around 40-45 degrees Celsius, without guaranteeing sufficient warmth. The lower the efficiency, the greater the required power, and the greater the likelihood of frost formation in air-cooled heat pumps. On the other hand, high water temperatures for gas boilers do not significantly reduce efficiency.

Third, does a water dispenser save costs? In terms of generating the same amount of heat, water dispenser operating costs are certainly lower than those of gas boilers when compared to tiered electricity prices. However, considering the difference in purchase costs and based on the assumption of a 10-year lifespan for the heat pump, the savings might not be significant. If gas prices are not tiered but electricity prices are, then air-cooled heat pumps do not save on operating costs.

Fourth, if you choose an air-cooled heat pump, firstly, it is recommended to buy a variable frequency one. Secondly, you must buy one with a variable frequency water pump or an externally installed variable frequency water pump. Approximately 40% of the electricity bills for my air conditioner are attributed to a fixed frequency water pump. Additionally, in winter, there is a troublesome issue of intermittent defrosting, although this is generally not a problem in Changsha, but overall, it is more troublesome than gas boilers.

Fifth, the water circuit design of a water dispenser has its own characteristics, and it requires experienced sellers. Simply copying the method used for gas heating is not suitable. A close spacing with multiple circuits is needed to ensure a large water flow required for the heat pump to operate. A differential bypass valve is required to ensure a minimum water flow when some circuits are closed. In addition, there should be interlocking installation, although I am skeptical about its effectiveness (I didn’t install it in my home).

Lastly, if you choose a water dispenser with full tiles, you can also consider utilizing ground cooling in the summer, which can partially absorb the heat load through radiant floor heating, thus improving comfort. However, the floor is prone to condensation, and I won’t delve into this complex topic.

Energy-saving and comfortable living with low cost

Compared to upgrading a residential property to a low-energy and healthy home, this is undoubtedly a solution that is both costly and uncomfortable to live in.

The cost is reflected not only in the high renovation investment but also in the future living expenses.

First, let’s state the conclusion: floor heating is not necessary in Changsha. Considering that the bedroom doors are closed during rest at night, each room only needs a 1 horsepower air conditioner for both heating and cooling.

If the rooms are on the sunny side, they can basically save electricity; for rooms on the shady side, three to five degrees of electricity per day are sufficient.

During the hot summer, air conditioning can save more than 35% of energy for cooling, and during the rainy season, it can save more than 35% of energy for dehumidification.

This is the reason for downsizing the air conditioning to 1 horsepower.

This energy-saving measure is based on the enjoyment of a warm and cool home, a clean and quiet, dry and comfortable living environment. In other words, it allows for a high-quality lifestyle while saving money.

Washing and drying combo or separate machines

Comparing the Functionality of Washer Dryer Combo and Separate Washer and Dryer Units

When it comes to the choice between a washer dryer combo and separate washer and dryer units, the question arises: which one is more convenient and useful? Let’s take a closer look to find out.

In the past, washer dryer combos were highly praised as the ultimate household appliance. They became incredibly popular for their ability to wash and dry clothes in a single machine, saving space and time. However, like any other product, their popularity eventually settled down.