I use Uniquel wall-hung boiler. The house is not hot. I don't know how to get rid of the residual air. What should I do? (Reward 100 points)

A: This is a complex system problem, and the reasons should be found from the following aspects:

(a), the choice of wall-hung boiler is appropriate?

(1), the choice of wall-hung boiler should be determined according to many factors such as the area where your home is located (different climatic conditions in different regions), the location, the building area, the envelope structure (villas, bungalows, energy-saving buildings, old buildings, etc.). ), height, floor, unit, heating terminal type, etc.

(2) The heating index in Huanghuai area is generally calculated according to 100 ~ 120 w/m2.h, and that in villas is generally calculated according to150 w/m2.h. Other areas can be determined according to relevant national standards and specific conditions. After the heating index is determined, the model of the selected wall-hung boiler can be calculated. For example, for a wall-hung boiler with a gas input power of 20KW, the thermal efficiency is 90% and the heating index is 120w/m2.h, so the theoretical heating area is 20000wx 90% ÷120w/m2.h = 65438+.

(3) Waterway system of wall-hung boiler: Generally speaking, the heating area of wall-hung boiler in closed waterway system is larger, and the heating area of wall-hung boiler in open waterway system is smaller than the theoretical heating area.

(2) Is the temperature setting of the wall-hung boiler reasonable?

There are many control concepts of wall-hung boilers: for example, some control the outlet water temperature, some control the backwater temperature, some control both the outlet water temperature and the backwater temperature, and some control the initial temperature difference of the outlet water (or backwater). Therefore, it should be set reasonably according to the model and heating method of the wall-hung boiler you choose. Therefore, please read your product manual in detail or contact the equipment supplier to master the operation method.

No matter what control method, in principle, the outlet water temperature (or backwater temperature) should be lower in warmer weather and higher in colder weather; The initial temperature difference should be larger in warm weather and smaller in cold weather.

In addition, if you control the outlet temperature, your waterway system is relatively large and the pipeline is relatively long, which may lead to poor water circulation. In order to avoid frequent shutdown, it is recommended that you lower the outlet water temperature. This is a helpless move in the case of unreasonable pipeline design. In this case, it is suggested to add synchronous circulating water pump to the pipeline.

Reminder: You can choose an indoor thermostat to control and adjust the indoor temperature.

(3) Is the choice of radiator appropriate?

(1), radiator configuration is very important, if the configuration is not appropriate, the heating effect is not good. The radiator configuration should be determined according to the area, orientation, envelope structure, function and other factors of the room. For example, the design heat load heating index of shady rooms is larger than that of sunny rooms, and the number of radiators is more; The temperature in the elderly room and children's room needs to be higher, so more radiators are needed. If the heating index of the radiator is lower than the heat loss per hour in the room, the heating effect can be imagined and it will never be warm.

How to judge whether the radiator configuration is enough? This paper introduces a simple calculation method: for the traditional horizontal radiator, the heating capacity of each row is at most 1.0~ 1. 1 m2, and the heating capacity of a single radiator is halved. Never listen to the misleading of some radiator dealers.

(2) Whether the choice of radiator matches the installation method. The internal structure of radiator with up-going and down-going installation mode is different from that with down-going and down-going installation mode. When ordering, you should indicate which installation method is used, otherwise it will affect the heating effect.

(3) Is the pipeline design reasonable? The pipeline design of gas-fired wall-hung boiler heating is different from central pipeline heating. Pipeline design should follow the following principles: the shortest pipeline principle, the principle of water balance, the principle of matching head and flow, etc. In addition, the design of "U" pipe should be avoided as far as possible. Some of them are not hot upstairs and downstairs due to unreasonable pipeline design, or some radiators are turned on and other radiators are not hot, or the hot end at the front end of the same floor is not hot. Due to unreasonable pipeline design, the wall-hung boiler may have increased load, increased noise, frequent start-up, no flameout, no automatic start-up, and so on. Even the wall-hung boiler may not work properly at all. Therefore, it is very important to choose a professional HVAC company.

The so-called "U" tube structure is to avoid bypassing the door frame as much as possible, otherwise it will form "air blockage", which will affect the circulation of the water pump, thus affecting the heating effect and the normal work of the wall-hung boiler. In the above situation, it is best to cut grooves on the floor to install pipes. If it is really unavoidable, it is necessary to install an automatic exhaust valve at the top corner of the pipeline (inlet and outlet). It should be noted here that many automatic exhaust valves are of poor quality and it is difficult to play the role of automatic exhaust.

For the inevitable long pipeline design, the pipeline circulation is not good because it has exceeded or approached the physical capacity of the "head-flow" curve of the built-in water pump in the wall-hung boiler. At this point, the synchronous gravity water pump should be installed on the pipeline, or a signal line should be led from the wall-hung boiler, and the circulating water pump should be installed with relay drive. At this time, it should be noted that the flow and speed of the two pumps should be the same or basically close.

Warning: The most reasonable pipeline design adopts the installation method of entering and leaving from below, and the radiator is higher than the inlet water and return pipe.

(4) Is the design and installation of floor heating reasonable?

(1), in terms of floor heating, floor tiles have better heat dissipation capacity, followed by wood floors. Therefore, for floor heating, it is best to lay floor tiles.

(2) Is the heat load design of floor heating reasonable? Has the insulation layer been laid? Are the physical properties (strength and thickness) of the insulation layer inferior?

(3) Is the design of floor heating pipeline scientific? Code for Design of Floor Heating requires that the length of each floor pipe should not exceed 80 meters, which will affect the water circulation and heating effect of wall-hung boilers. According to the above principles, the laying of floor heating pipes in the living room should be designed as 2 ~ 3 circulating waterways, otherwise the living room will not be hot. There are many such negative examples in reality.