Household central air conditioning is a miniaturized independent air conditioning system, similar to large-scale commercial central air conditioning in refrigeration mode and basic structure, through a host and multiple terminal equipment connection to send cold and heating to different areas, to achieve the effect of temperature regulation in multiple rooms. Household central air conditioners are mainly divided into two types: water system and fluorine system according to the different media conveyed by the host to the end.
Water system vs. fluorine system
| Compare items | water system | Fluorine system |
| circulatory system | Water (refrigerant) | Freon (refrigerant) |
| thermal efficiency | The temperature rises more slowly | The temperature rises quickly |
| Heating effect | Wide heating range down to -20°C | The effect is poor below -5°C, and electric auxiliary heating is required |
| Comfort | The moisture does not disappear easily, and the temperature gradient is small | The temperature gradient is large, the use time is long, the indoor air is dry, and there is an uncomfortable feeling |
| reliability | The terminal equipment is controlled independently, and the failure of one terminal will not affect the use of other terminals | The outdoor unit is connected to the control of the indoor unit, and once a certain indoor unit fails, the whole system cannot be used |
| safety | The refrigeration system is concentrated in the outdoor unit, which is safe and reliable | The refrigerant is distributed throughout the system, and there is a high chance of leakage |
| Radioactivity | It does not produce high-frequency harmonics, has superior electromagnetic compatibility, and has zero interference with electrical equipment | It will produce high-frequency electromagnetic harmonic radiation, which will interfere with the human body and precision electrical appliances |
| Maintenance | The performance is stable and the maintenance cost is low | The maintenance cost is high in the later stage |
| Service life | The design life of the water machine is 15 years | The design life of the fluorine machine is 15 years |
There is basically no central heating in northern towns and villages, and there is no pipeline gas in many places, so air can become the best or even the only choice for heating after coal to electricity.
| merit | shortcoming | |
| Gas boilers | Simple, energy-saving, can be installed on the wall, in the corner of the room, inexpensive, simple maintenance, low initial cost. | There are hidden dangers such as safety and pollution, the scope of application is limited, the temperature control is unstable, the service life is limited (8 years), and the operating cost is high. |
| Regenerative electric boilers | The initial investment cost is moderate, easy to use, the temperature can be self-adjusted, and the floor space is small. | It needs to be preheated, the amount of one-time use is limited, the safety factor is average, the power consumption is relatively high, the service life is limited (8 years), and the operating cost is high. |
| Air source heat pumps | Clean and safe, energy-saving and efficient, wide range of application (-25°C~55°C), stable performance, can be installed in combination with linkage, small footprint, convenient temperature adjustment, durable (service life of 15 years), not easy to damage, low operating cost. | Installation and initial costs are higher. |
The difference between central heating and household heating:
The biggest feature of central heating is regional heating, a coal boiler supplies heating to a large area at the same time, lacks flexibility, each household is located on the floor, the structure has different number of residents in the actual application, the heat required is not the same, the central heating user can not adjust the heating temperature according to their own needs, and there is often a situation that the indoor temperature of some families is too high and needs to open the window to cool down, which is not good for both wasting energy and effect.
The use of household heating can completely solve the above problems, each household has its own independent heating system, each household can adjust the heating temperature and heating start and stop time according to their own situation, more flexibility.
At present, the central heating in China is mainly based on coal and fuel oil as the main raw materials, which will produce polluting gases and substances in the process of use, and pollute the air in the entire region, so the country has also reduced and banned the consumption of coal in recent years, and sought the transformation of heating.
The use of air source heat pump household heating mode, due to the addition of a large number of low-grade heat energy in the air, the use of 1KW of electric energy can produce 4KW of thermal energy, the heating efficiency is much higher than coal and natural gas, saving the use of costs, and air energy is recognized as clean energy, the use of the process is non-toxic, harmless and pollution-free, can more effectively inhibit air pollution and haze in the northern region.
To sum up, no matter in terms of user experience, energy consumption or sustainable development, air energy heat pump household heating has obvious advantages, and will gradually replace the existing centralized heating method.
Environmental setting: construction area of 120 square meters, heating area: 100 square meters, heating cycle of 120 days. Heating consumption load: 50 watts per square meter (W/㎡).
Total heat consumption of 100 square meters in 1 day: Q total heat = (heating load 50W/㎡×100㎡×24h ÷1000W/KW) ×860Kcal/KW.h=103200Kcal
Application of heating heat pump: heating + hot water
Heating (hot water) scheme design steps:
| 1 | Heating area calculation | According to the data, drawings, or on-site measurements provided by Party A |
| 2 | Heat load calculation | Inquire about the local heating design temperature, house insulation, user requirements, etc |
| 3 | Model selection | The model is selected according to the heat load and temperature of the heating season, combined with the attenuation coefficient of the unit, the user's installation position, and the power supply voltage |
| 4 | End selection | According to the needs of the user and the heating area, installation location, etc |
| 5 | Draw a system diagram | Drawing of the system (construction drawings) |
| 6 | Quote budget | Make a cost estimate, make a quotation (to the user) |
Heating (hot water) scheme design case:
(1) Overview
There is a house in Beijing, with a heating area of about 100 square meters, three bedrooms and a living room (dining room), which needs heating and domestic hot water.
(2) Heat load and selection calculation
The heating heat load is related to many factors such as the heat consumption of the envelope structure, the heat consumption of the cold air infiltrating into the room through the door and window gaps, and the heat gain inside the building, which need to be calculated and determined according to the specific situation.
The total heating area is 100m2, and the end adopts a special floor heating machine for generating energy, and the heating heat index is calculated as 80W/㎡;
采暖负荷：100×80=8kW
According to the calculated temperature (-7.6 °C) outside the local heating room, a unit is preliminarily selected to produce about 12.2kW of heating under the temperature of -7.6 °C, which can meet the heating demand.
Design reference standard: GB50736-2012 "Design Code for Heating, Ventilation and Air Conditioning of Civil Buildings"
(3) Quotation list
List of materials required for system installation (common house types)
(4) Room layout
(5) System connection diagram
Application of heating heat pump: heating + cooling
Schematic diagram of the connection of heating heat pump:
Household heating + cooling solutions (secondary systems):
System installation diagram:
Heating and cooling scheme design steps:
| 1 | Air conditioning area calculation | According to the data, drawings, or on-site measurements provided by Party A |
| 2 | Calculation of cooling and heating loads | Inquire about the local air conditioning, heating design temperature, house insulation, user requirements, etc |
| 3 | Model selection | According to the cold and heat load and the temperature of the heating season, combined with the attenuation coefficient of the unit, the user's installation position, the power supply voltage, etc., the model is selected, according to the principle of high not low |
| 4 | End selection | According to the needs of users, cooling and heating area, installation location and other options |
| 5 | Draw a system diagram | Drawing of the system (construction drawings) |
| 6 | Quote budget | Make a cost estimate, make a quotation (to the user) |
Selection of air conditioner host:
The sum of the cooling/heating load of the air conditioner in each room is the total cold/heat load of the air conditioner required for the house, and then multiplied by the simultaneous use coefficient of the air conditioner (the simultaneous use rate of the air conditioner in the residence is generally 70~85%), and the value obtained is the required air conditioning host refrigeration/heating, according to this value, the model and quantity of the air conditioning host that meet the needs are selected, and the following principles need to be observed when selecting the model:
(1) The selected model needs to meet the needs of cooling capacity in summer and heating in winter at the same time;
(2) The heating capacity of the selected model shall be combined with the local average winter temperature, and the heating production shall prevail at the local heating design temperature.
Heating changes of the unit at different ambient temperatures
Reference for the selection of various apartment types
Heating and cooling terminal type
Heating and cooling load at the end of heating and cooling
Calculate the cooling/heating load of each room according to the cooling/heating load index per unit area of the room function and use, and select the corresponding model of air-conditioning terminal equipment that meets the cold/heating load requirements of the room, and the following are the cooling/heating load indicators per unit area of each type of room (for reference only).
The actual use of air conditioning is very different, the above table values are for reference only, the application should be combined with the actual situation to make appropriate adjustments and corrections, do not rote memorization, in case of the following situations, the load index needs to be appropriately increased by 15~25% to meet the needs of actual use:
A. The room is located on the top floor of the building, B. The outer wall of the room is located on the west side;
C. The exterior wall of the room is a large area of glass or floor-to-ceiling glass, D. The ceiling height of the room is more than 4 meters.
Saleable area of fan coil unit (reference):
Quotation (multiple combinations):
Auxiliary Accessories Selection:
(1) Auxiliary accessories - for the return of water main
Generally, PPR pipes, galvanized steel pipes or stainless steel pipes are selected, and the water flow rate of the pipeline is calculated first (the temperature difference between the supply and return water is calculated by 5 °C): the water flow rate of the pipeline (m³/h) = cold (heat) load (kW) ×860÷5000
Then select the corresponding pipe diameter according to the table below. When the pipeline is long, in order to ensure the hydraulic balance, the variable diameter and the same stroke design of the pipeline should also be considered.
Pipe Diameter/Flow Rate/Flow Comparison Table:
(2)辅助配件——循环水泵
Selection suggestions:
Heating (air conditioning) circulating water pump must be selected hot water pump, and its Q~H characteristic curve should be the curve of gradual decrease of head with the increase of flow. The pump should be selected according to the parameters provided by the equipment provider and according to the requirements of the on-site hydraulic system, and the pump should operate in its high-efficiency zone.
According to the total water flow rate at the end or the circulating water flow rate of the main engine (whichever is the larger of the two values, the selection is based on).
Estimation of the head of the circulating water pump - the resistance composition of the closed air conditioning water system:
Water resistance P1 of air conditioner main unit: about 30~80KPa(3~8M)
管道沿程阻力P2:约150 ~200pa/m (0.015~0.02M/m)
Pipeline local resistance P3: 50% of the resistance along the way
Fan coil unit water resistance P4: about 10~20KPa(1~2M)
电动二通阀水阻P5:约40KPA(4M)
The sum of the resistance of the above water system, and then consider the safety factor of 10% as the basis for selecting the pump head, that is, the pump head required by the water system is: H = 1.1 * (P1 + P2 + P3 + P4 + P5)
Calculation method: rated flow rate (m³/h) = cooling or heating load (kW) ×860÷5000
(3) Auxiliary accessories - floor heating pipes
a) Heating tube length calculation
Simple calculation of the length and loop of the heating coil (e.g. 10 square meters in the heating room, 10 meters from the manifold)
Heating coil length recommendation: the length of each loop heating coil should be controlled at 60~80 meters, the longest should not exceed 100 meters, the length of each loop should be equal or similar, and the pipe length difference should be controlled within 15 meters.
b) Heating tube material
Basic requirements: Polybutylene (PB), cross-linked polyethylene pipe (PE-X), heat-resistant polyethylene pipe (PE-RT) for hot water that meet the requirements of the corresponding national standards, and are also suitable for water/ethylene glycol (up to 30%) solution.
Selection suggestion: because the air source heat pump heating is a low-temperature heating method, the energy efficiency is relatively high when the water temperature is 40 °C, and the heating pipe should choose a pipe with an outer diameter of Φ16 or below, and the pipe spacing is small to increase the heat supply.
(4) Auxiliary accessories - dividers and water collectors
Basic requirements: Brass or stainless steel, suitable for water/glycol (up to 30%) solution.
Selection suggestion: select the number of manifold branches according to the number of coil loops, the number of branches should be controlled within 8 channels, if more than 8 channels, you can add another set of manifolds to solve. The larger the number of branches, the larger the diameter of the main pipe of the manifold, which is subject to the actual hydraulic calculation.
(5) Auxiliary accessories - expansion tank
Basic requirements: rust prevention, and at the same time suitable for water/glycol (up to 30%) solutions.
(6) Auxiliary accessories - filter
Basic requirements: the material is made of brass or stainless steel, brass is recommended, the filter screen is made of stainless steel, and it is suitable for water/glycol (up to 30%) solution.
General Specifications:
Selection suggestion: The function of the filter is to collect the materials in the system and avoid the materials affecting the normal operation of the system. The larger the number of filter meshes, the finer the particle size of the material, and the smaller the number of meshes, the larger the particle size of the material. The caliber of the filter should be consistent with the diameter of the main water supply pipeline of the system or one specification larger than the diameter of the pipeline.
(7) Auxiliary accessories - safety valve
Basic requirements: Brass or stainless steel, suitable for water/glycol (up to 30%) solution.
When the system pressure exceeds the specified value, the safety valve is opened, and a part of the hot water in the system is discharged out of the system, so that the system pressure does not exceed the allowable value, so as to ensure that the system does not cause accidents due to excessive pressure. The setting pressure (starting pressure) of the safety valve is consistent with the maximum working pressure of the system. Generally, refer to the parameters provided by the equipment provider.
(8)辅助配件—管件、阀门
Basic requirements: Material: brass, galvanized, stainless steel or plastic, and suitable for water/glycol (up to 30%) solution.
Selection suggestions: pipe fittings and valves should be supplied by pipe manufacturers.
(9)辅助配件—自动补水阀
Automatic water replenishment valve is a new type of valve installed on the water supply pipeline of closed cycle heating or cooling system, which can automatically maintain the pressure of the system as the set value, the check valve in the valve can prevent the hot water of the heating system from flowing back to the cold water pipeline, the internal filter of the water replenishment valve can avoid impurities from flowing into the system, even if the pressure of the water supply end changes, it can also maintain the stability of the outlet pressure, the hand wheel can completely cut off the water flow in an emergency, and the water supply valve is a new type of valve integrating the functions of pressure reducing valve, globe valve, check valve and filter.
(10) Auxiliary accessories - automatic exhaust valve
Basic requirements: Brass or stainless steel, suitable for water/glycol (up to 30%) solution.
Selection suggestion: because there is usually a certain amount of air dissolved in water, and the solubility of air decreases with the increase of temperature, so that the gas is gradually separated from the water in the process of water circulation, and gradually gathers together to form large bubbles or even air columns. During the operation of the heat pump system, the many adverse effects caused by the gases such as oxygen released when the water is heated will damage the system and reduce the thermal effect, and these gases will have many adverse consequences if they are not discharged in time.
(11)辅助配件—缓冲水箱/膨胀水箱
Buffer water tank capacity of the system: The capacity of the buffer water tank of the winter and summer air conditioning system can be calculated according to the following formula.
In the equation: Q is the heating or cooling capacity of the terminal equipment, kW;
δ is the time required for thermal stability (δ=10/60h);
Cp is the specific heat capacity of water at constant pressure, kcal/(kg·°C);
Δt is the required value for the temperature fluctuation of water (Δt = 5°C).
(12)辅助配件—压差旁通阀
When the water quantity control mode of the system adopts the variable flow mode, which is controlled by the indoor temperature controller to open and close the electric two-way valve, when the fan stops and the electric two-way valve is closed, it is necessary to install a differential pressure bypass valve on the air-conditioning main to stabilize the water flow into the unit.
Installation:
Schematic diagram of the installation of heating heat pump:
Commonly used accessories:
Common tools for installation and maintenance:
Table of common accessories for heating heat pumps:
Installation process:
Step 1: Contact the installation when the water and electricity enter the site. Hoisting the central air conditioning indoor unit - fan coil unit, and wrapping the fan coil unit to avoid dust and impurities, install the pipe pipe: water supply and return pipe, condensate pipe, signal line.
Step 2: 24 hours after the first installation, hoist the outdoor unit of the central air conditioner, test the central air conditioning system, and measure the size and position of the tuyere.
Third installation: After the second installation is completed or the indoor ceiling installation is completed, the tuyere is installed, and finally the equipment is tested.
(1) Host installation
Installation location selection:
It can be installed on the ground base;
It can be installed on a balcony that can bear the weight of the unit;
Can be installed on prefabricated stands for this equipment;
It can be installed on the roof base;
It can be installed in any position that can meet the required conditions of the unit.
The installation location of the unit shall meet the following conditions:
1) The air outlet of this machine is not directly sucked by this machine or other machines.
2) There are no obstacles on the air duct, if there are, remove all obstacles blocking the air inlet and air outlet.
The outdoor unit is installed horizontally within 1 ゚ ± * sufficient heat dissipation space should be ensured;
* Keep away from bedrooms, study rooms and other places with high noise requirements to avoid noise and exhaust affecting users and surrounding residents.
*The base height of the outdoor unit should be more than 200mm, and there must be enough space for maintenance and operation.
*Shock-absorbing pads (thickness ≥ 10mm) must be installed on the feet of the outdoor unit to ensure the normal and stable operation of the outdoor unit.
The host installation location should meet the following conditions:
Do not install in places where the content of dust or oil in the air is too high (to avoid the condensation coil can be easily blocked) or near flammable gases. There should be enough space around the unit to facilitate the return air of the unit and facilitate maintenance.
(2) Water supply and return pipeline system
Galvanized steel pipe pipe installation
Please follow the plumbing plumbing standards for proper construction.
Select the appropriate pipe diameter according to the given piping size.
The pressure difference between the indoor fan coil unit or main pipe and the inlet and outlet of the unit should be reduced as much as possible.
The entire pipeline system should be clean and free of rust and dirt to prevent clogging of the pipeline.
The required flow rate at the end of the size is different, and the diameter of the pipe should be selected according to the required flow rate at the end.
Reducer should be close to the end.
Vibration damping device: reduce vibration and prevent noise from entering the room;
Overhaul valve: It can be closed during maintenance to isolate the unit from the piping system;
Maintain sufficient water pressure in the system;
Installation of water pressure gauges and thermometers for easy maintenance and repair;
Install a filter in front of the pump to remove impurities from the water.
PPR pipeline installation (more commonly used in some small central air-conditioning projects)
1) In order to ensure the installation quality of PP-R pipes, the elliptical ratio of the pipe diameter shall not exceed 10%, the wall thickness deviation of the same section of the pipe shall not exceed 14%, and the inner and outer walls shall be smooth, flat, free of bubbles, cracks, cracks, depressions, peeling and obvious marks.
2) PP-R pipe cutting using a small copper pipe cutter, the blade is perpendicular to the outer wall of the pipe, the knife should not be too tight, first rotate around a week to carve out the cutting line, each rotation into a certain depth of the knife (generally controlled between 1/4 ~ 1/2 of the thickness of the pipe wall), when the pipe is about to be cut, put it slowly to rotate to prevent the broken pipe from falling. At the cutting point, the inner necking part of the nozzle should be expanded with a taper knife, or the chamfer in the nozzle should be eliminated with a round file. It can also be cut off with special pipe scissors: the bayonet of the pipe scissors should be adjusted to be consistent with the diameter of the broken pipe, and the force should be evenly applied when rotating and cutting.
3) The installation connection of PP-R pipe can be hot-melt connection, which is the most reliable and widely used. It is easy to operate, has good air tightness, and has high interface strength. Pipes laid in the wall and underground, must be hot-melt interfaced.
Before connection, the pipe end is processed with a groove of about 30 degrees, the blunt edge is retained 1/3~2/3 wall thickness, and the connected pipe fittings and pipe ends are wiped clean with cotton yarn, and the right to use is oil-free and dust-free, and the insertion depth is marked.
When connecting, the tube end is introduced into the heating head without rotation to reach the specified mark. The heating time must meet the requirements. After the heating time is reached, immediately remove the pipe and pipe fittings from the heating sleeve and heating head at the same time, and insert them into the marked depth quickly and evenly without rotation to form a uniform flange at the joint. Freshly welded joints can also be calibrated within the processing time specified in the attached table.
4) When the PP-R pipe is connected with the metal pipe fittings, the pipe with metal threaded inserts is used as the transition, the pipe fittings are connected with the PP-R pipe by hot melt socket, and when the pipe fittings are connected with the metal pipe fittings or hardware fittings, the spiral connection is adopted, and the polyvinyl fluoride raw material tape is used as the sealing filler, and thick white paint and hemp wire should not be used.
5) The pipe support should be buried before the pipeline is installed, and the maximum installation distance of the cold and hot water pipe support should meet the relevant requirements of the attached table.
6) The longitudinal and transverse bending of horizontal pipes, the verticality of risers, and the installation deviation of rows of pipes and valves meet the relevant requirements of the attached table.
7) System hydrostatic test requirements:
(1) The test pressure is 1.5 times of the working pressure of the system, but shall not be greater than the allowable pressure of the pipe.
(2) Water should be injected slowly during the test, and the water tightness should be checked after the filling is full.
(3) After the pressure is slowly increased to the test pressure with a hand pressure pump, the pressure is stabilized for 1h to check that there is no leakage, and the pressure drop within 15min is 0.05MPa is qualified.
Water pipes (galvanized steel pipes, PPR pipes)
Technical requirements for hot melt connection of PP-R pipes
| Tube Outer Diameter(mm) | Welding Depth(mm) | Heating time(s) | Processing time(s) | Cooldown(s) |
| 20 | 14 | 5 | 4 | 3 |
| 25 | 16 | 7 | 4 | 3 |
| 32 | 20 | 8 | 4 | 4 |
| 40 | 21 | 12 | 6 | 4 |
| 50 | 22.5 | 18 | 6 | 5 |
| 63 | 24 | 24 | 6 | 6 |
Note: If the ambient temperature is lower than 5°C, the heating time should be extended by 50%.
The maximum installation spacing (mm) of PP-R pipe cold and hot water pipe bracket is scheduled
| Pipe diameter | 15 | 20 | 25 | 32 | 40 | 50 | |
| cold water | Horizontal tubes | 600 | 800 | 1000 | 1100 | 1200 | 1400 |
| Risers | 1000 | 1200 | 1500 | 1700 | 1800 | 2000 | |
| hot water | Horizontal tubes | 500 | 600 | 700 | 800 | 900 | 1000 |
| Risers | 900 | 1200 | 1200 | 1400 | 1600 | 1700 |
Allowable deviation of PP-R pipe installation(mm)
| project | Allowable deviations | |
| The horizontal pipe is bent in the longitudinal and transverse directions | per 1 meter of pipe | 5 |
| every 10 meters of pipe | Greater than 10 | |
| Outdoor overhead, trench, buried every 10 meters | Greater than 15 | |
| Riser verticality | per 1 meter of pipe | 30 |
| Pipes with a height of more than 5 meters | Greater than 10 | |
| Risers over 5 meters every 10 meters | Greater than 10 | |
| Rows of pipes, valves | Spacing on the same line | 3 |
Water Lines:
The exhaust valve should be installed at the highest point of the water system, the drain valve should be installed at the bottom of the water system, and the pipe hanging bracket: fixed bracket and movable bracket.
Branch Pipeline:
(3) Electric valve
installation of motorized valves;
An electric valve is a device that cuts off or bypasses the end;
The installation should be as close to the end as possible;
After the shut-off valve is closed, it should be easy to repair;
The installation location should be convenient for after-sales service;
Before and after installation, it should be powered on to observe whether the opening and closing are reliable.
(4) Fan coil unit, floor heater, radiator installation
A. Fan coil unit installation
1. The 4 booms that fix the fan coil unit should be firm, and the upper plane of the coil should be leveled with a level, so as to meet the condensate discharge outlet from the slope of the water tray at the lower end of the coil.
2. The cold and warm water pipes connected with the fan coil unit should be connected with soft joints, and the air outlet of the fan coil unit should also be softly connected, so as to reduce the noise.
Precautions for hoisting indoor unit:
1. The horizontal installation ±of the indoor unit is within 1 ゚, and it must be leveled with a level;
2. The indoor unit has enough space for air supply and return;
3. The indoor unit has enough space for repair and maintenance;
4. After hoisting the indoor unit, it should be protected in a timely and all-round way;
5. The size of the maintenance port (maintenance port) should be more than 400×400mm.
※The screw rod is not less than ¢10mm;
※The screw rod should be kept vertical;
※The length of the screw rod is unified in the middle position of the machine;
※The indoor unit is fixed with double nuts under hoisting;
B. Installation of special floor heating machine
Installation Guide and Precautions:
1) The unit should be installed by professionals who are proficient in such products and relevant local regulations.
2) In order to eliminate the unexpected situation that may be caused by handling, the leak detection inspection of the coil unit of the unit should be carried out (1.0Mpa) before installation.
3) Before installation, first check whether the preliminary preparations are in place, such as water pipes, wire interfaces, etc.
4) The unit should be placed on the horizontal ground to avoid tilting, and at least 20-30mm from the wall should be reserved on the left and right sides to facilitate smooth return air.
5) When the unit is installed, the connection between the water pipe and the unit is recommended to be sealed with flexible pipe and raw tape, and the pipeline should not be connected with too much force, and the torque should not exceed 205.6N.M to avoid torsion and leakage.
6) A water filter should be installed on the water inlet pipe of the unit to avoid dirt blocking the coil pipe, and an exhaust valve should be installed at the highest point of the waterway system, and the exhaust valve should be opened to bring out the air in the system pipe before commissioning and use.
C. Installation of radiators (mainly four materials: copper aluminum, steel, all-aluminum, cast iron)
The installation size of the radiator and the number of supporting hooks vary with the variety of radiators, which can be carried out in accordance with the product sample and construction inspection standards or the standard drawings of heating equipment devices in the country or region. Usually, the number of upper hooks is small, which is used to ensure the verticality of the radiator, and the number of lower unhooks is large, which mainly plays a load-bearing effect. The primary installation dimensions of radiators are as follows:
(1) Usually the interval between the back of the radiator and the wall skin is 30-50mm, except for special needs;
(2) The height of the lower edge of the cast iron radiator from the ground is usually 70-80mm;
(3) The height of the lower edge of the hanging radiator from the ground is usually l00-150mm;
(4) When the wall niche type is semi-concealed, the lower edge of the upper edge of the radiator should be greater than 100mm.
(5) Return air outlet and air supply outlet
Examples of return air outlets and supply air outlets:
Calculation of return air outlet and air supply outlet:
One or more can be selected according to the size of the end and the area can be calculated under the return air speed not exceeding 2m/s.
The air supply outlet can be selected according to the wind speed, airflow organization, air supply distance, room function and user requirements;
(6) Condensate pipes
(PVC pipe, aluminum-plastic pipe, galvanized steel, pipe inner diameter is not less than 20mm)
The condensate pipe should be set up according to the following principles: the condensate pipe should be arranged as close to the discharge site as possible to reduce the length of the condensate pipe.
Pay attention to the discharge slope of the condensate pipeline, and try to ensure that it is ≥1%. The condensate pipe should be softly connected to the unit.
Correct installation of the fixed code:
The fixed spacing of the drainage pipe is 0.8~1.0m/piece, and the turning of the drainage pipe should be fixed at 300mm. Natural drainage of indoor units without lifting pumps;
The random drainage hose should be installed horizontally, and the drainage slope should be more than 1/100 of the drainage.
Condensate pipe installation example:
(7) Floor heating pipe installation
Industry standard: JGJ142-2012
Heating coil length recommendation: the length of each loop heating coil should be controlled at 60~80 meters, the longest should not exceed 100 meters, the length of each loop should be equal or similar, and the pipe length difference should be controlled within 15 meters.
(8) Installation of air ducts
(Galvanized sheet air duct, phenolic composite air duct, SUS plate air duct)
Process flow: air duct → (determine the elevation→ make hangers→ set hanging points→ install hangers→ install in place, align and level) (synchronize air duct arrangement and air duct connection) → inspection.
a. Before the installation of the air duct, further check whether the position of the installed supports, hangers and brackets is correct and whether they are firm and reliable.
b. According to the hoisting method determined by the construction plan (overall hoisting or hoisting section by section), hoisting shall be carried out in accordance with the installation sequence of the main pipe first and then the branch pipe.
c. The horizontal installation of the air duct can be adjusted by the adjusting bolts of the hanger or by adjusting the skids on the bracket.
d. After the air duct is installed in place, you can use the method of pulling wire, level ruler and hanging wire to check whether the air duct is horizontal and vertical.
e. For horizontal installation of air duct, the allowable deviation of horizontality should not be greater than 3mm per meter, and the total deviation should not be greater than 20mm, and the allowable deviation of verticality should not be greater than 2mm per meter and the total deviation should not be greater than 20mm for vertical installation of air duct.
f. There should be rainproof and leakage prevention measures at the place where the air duct passes through the roof and the outer wall, and the air duct through the roof should be determined according to the air duct diameter, roof height, pipe wall thickness, roof height and other factors.
Air duct manufacturing process
a) Draw a processing sketch: draw according to the construction drawings;
b) The production of rectangular air duct connected by flange: for the rectangular iron duct with a large side length between 120~1250mm, the material selection should be in accordance with the design requirements.
| 镀锌钢板风管选材厚度表（mm） | Stainless steel plate air duct thickness table(mm) | |||
| Duct diameter or long-side size | Round ducts | Rectangular ducts | Duct diameter or long-side size | thickness |
| 80～320 | 0.5 | 0.5 | 100～500 | 0.5 |
| 340～450 | 0.6 | 0.6 | 530～1120 | 0.75 |
| 480～630 | 0.8 | 0.6 | 1180～2000 | 1 |
| 670～1000 | 0.8 | 0.8 | 2500～4000 | 1.2 |
| 1120～1250 | 1 | 1 | ||
| 1320～2000 | 1.2 | 1 | ||
| 2500～4000 | 1.2 | 1.2 |
(9) Installation of insulation materials
(PE heat insulation, plastic plastic heat insulation)
Construction technology of insulation materials:
1) Materials and tools for insulation construction of air conditioning ventilation pipes
a. Main construction material: PEF insulation board (thickness of 8, 10, 12, 15, 20, 25mm)
b. Construction auxiliary materials: insulation seal, special glue for air duct insulation (dosage: about 5m2/L)
c. Construction tools: cutting knives, brushes, rulers, tape measures, roller brushes
2) Key points of construction technology
a) The joints of each insulation board shall be affixed with thermal insulation seals to ensure sealing;
b) Each flange, valve, and soft joint shall be pasted with a thermal insulation board of the same thickness;
c) The outer diameter of each boom should be padded with a 20mm thick insulation strip to prevent the insulation thickness from being too thin after compression;
d) Roller brush for large-area gluing on the surface of the insulation board and air duct must ensure that all aspects are covered, in which the gluing of the insulation board can be carried out in advance, and can be stacked in turn after coating without sticking, and the gluing on the surface of the air duct can be glued while gluing during construction, and the insulation board can be pasted on the same side;
e) The insulation board shall be pasted before the installation of the air duct, the flange section shall be sealed with the insulation tape, and the insulation board at the flange interface and bone insertion interface shall be reserved for 5mm to ensure that the insulation board on both sides is compressed and sealed with each other during connection and installation.
| item | project | Allowable deviations | Test Method |
| 1 | Insulation flatness | 5mm | Inspect with a 1M ruler and a wedge feeler gauge |
| 2 | Insulation thickness | -0.05～+0.10 | Pierce the insulation layer with a steel needle and measure it |
Description of pipeline insulation construction method
1) Materials and tools for pipeline insulation construction
Main construction material: PEF insulation casing
Construction auxiliary materials: insulation seal, special glue for insulation pipe sleeve (dosage: 9L/m3)
施工用具：切割刀、毛刷、直尺、卷尺、电烙铁
2) Construction technical specifications
A) All joints must be bonded and sealed with special glue, and there shall be no gap between the pipe wall and the outside air;
B) The glue of the insulation pipe sleeve is in the range of 20~50mm on both sides of the butt joint and the inner surface on both sides of the butt joint, and the glue can be applied for 3~5 minutes before bonding;
c) If a single-layer pipe sleeve is used, a thermal insulation seal should be affixed to the vertical and horizontal joints to ensure that the joints are sealed;
D) During the construction of the double-layer pipe sleeve, the joints need to be staggered, and the outer layer can not be affixed with thermal insulation seals to ensure that the joints are sealed;
E) Closed sleeve opening method: the opening line should be close to the tangent line of the circumferential circle of the pipe sleeve, and should not be perpendicular to the tangent direction, so as to increase the pasting area and avoid direct communication with the outside air when there is a gap in the joint.
3) Description of construction methods
a) elbow insulation construction method: adopt fan-shaped cutting construction method or shrimp tail section cutting construction method;
b) pipeline support construction method: the use of the same thickness of the insulation thickness of the wooden support support, after the pipe insulation, with a thickness of 10mm insulation board to make a thickness of 100mm, the length of the insulation pipe sleeve outer perimeter of the insulation strip is attached to the wooden support.
c) valve insulation construction method: valve insulation can be used in two layers according to the shape of the valve for thermal insulation, first the valve stem part is wrapped into a cylindrical shape, and then the valve body is filled with a strip insulation tape into a relatively neat cylinder, and then the outer layer of construction, the port of the valve stem should be made with the same thickness of the circular sealing plate for pasting, so that it needs to be disassembled and assembled when maintenance.
d) Tee insulation construction method: tee insulation must comply with the order of first small-diameter pipe and then large-diameter pipe, on the opening line of large-diameter insulation pipe sleeve with a cutting knife to open a small diameter pipe sleeve of intersecting round holes, round holes and small pipe sleeves around the coating glue to ensure sealing.
(10) Installation of water pumps
(1) Foundation pay-off
According to the construction drawings according to the axis, the pump installation center line is popped up on the surface of the foundation with an ink line, and the installation elevation is determined by a steel plate ruler according to the red triangle mark of civil engineering on the foundation.
(2) Foundation surface treatment
Shovel the hemp surface at the place where the horn is placed on the foundation, so that the concrete poured during the secondary grouting is closely integrated with the foundation. The standard for shoveling hemp noodles is that there should be 5~6 small pits with a diameter of 10~20mm within 100cm2. Remove oil, gravel, mud, and stagnant water from the foundation surface and anchor bolt holes
(3) The pump is transported in place
Pave a flat passage to the foundation side with road wood or timber, make the channel and the foundation equal height at the junction with the foundation, and the road wood is a roller bar, and the pump is rolled to the foundation.
(4) Alignment and leveling
1) Straighten the pump, and hang the vertical line with a line pendant in the center of the water inlet and the center of the shaft of the pump, so that the tip of the line hammer and the center line of the foundation surface intersect.
2) Place two sets of horns on both sides of each anchor bolt, and one set of horns in the middle of the two bolts in the pump length direction. Use a No. 3 flat horn and an oblique horn
3) Use a steel ruler to measure the elevation of the center line of the pump shaft, which is consistent with the design requirements to ensure that the pump can work within the allowable suction height.
4) Level the pump by adjusting the thickness of the horn, place the level on the pump shaft to measure its longitudinal level, and place the spirit level on the flange surface of the pump outlet to measure its transverse level.
(5) Secondary grouting
After the pump is aligned and leveled, each group of horns is welded to each other with positioning welding. Clean the grout and wipe off the stagnant water. Concrete is configured with Portland cement No. 525 and fine crushed stone. When grouting, it should be tamped, and care should be taken not to tilt the anchor bolts and affect the accuracy of the pump. After the concrete is solidified, when its strength reaches more than 75% of the design strength (7 days at room temperature), tighten the anchor bolts. The bolt should expose the nut, and its exposed length should be 8~10mm. The position and level of the pump are double-checked.
Allowable deviation of foundation size and position:
| project | Allowable deviation (mm) |
| Coordinate location | ±20 |
| Different plane elevations | -20 |
| Base form factor | ±20 |
| Basic leveling | |
| (1) per meter | 5 |
| (2) Full length | 10 |
| Embedded anchor bolt holes | |
| (1) Central location | ±10 |
| (2) Depth | ﹢20 |
| (3) Plumb degree of hole wall | 10 |
The distance between any part of the anchor bolt and the hole wall should be greater than 15mm, and the bottom end of the anchor bolt should not touch the bottom of the hole.
After the pump is leveled, each group of horns should not exceed 4 pieces. The end face of the horn should be exposed to the outer edge of the bottom surface of the pump, the flat horn should be exposed 10mm to 30mm, and the oblique horn should be exposed 10mm to 50mm. The length of the horn set protruding into the bottom surface of the pump base should exceed the center of the anchor bolt.
The allowable deviation of the pump installation plane position to the centerline of the installation datum is ±10mm, and the allowable deviation between the installation elevation and the installation datum elevation is ±10mm.
(11) Electrical installation
Electrical Wiring:
Electrical wiring installation requirements:
380V Motor:
Calculation formula:
I=P/(1.732×U×cosφ×η)=7500/(1.732×380×0.85×0.9)≈15(A)
Empirical formula: I=2×P=2×7.5=15(A)
220V Motor:
Calculation formula:
I=P/(U×cosφ×η)=7500/(220×0.85×0.9)≈45(A)
Empirical formula: I=2×P=6×7.5=45(A)
Below 10mm2 can be multiplied by 5 times the cross-sectional area.
16，25mm2乘以4倍，35，50乘以3倍，70，95乘以2.5倍，120，150，185mm2乘以2倍。
Wiring Material:
Power cord (strong current) selection criteria:
The wiring of the air conditioner must meet the rated total current value of the outdoor unit, indoor unit and auxiliary equipment (auxiliary electric heating, water pump, etc.) *1.25, and the voltage drop shall not exceed 2% of the rated voltage.
Electrical casing material standard:
The inner and outer walls are smooth, the threading resistance is small, the flame retardant, the insulation is good, the corrosion resistance is anti-aging, the impact resistance is strong, the mechanical strength is high, it can withstand the voltage, it is odorless and the five poisons.
Signal line selection: choose the original twisted pair or shielded twisted pair of the unit.
The air-conditioning communication wiring requirements are carried out by professional electrical technicians;
The communication lines selected in the installation of electrical equipment must use products that have been certified by the state;
For communication lines, 0.75-1.25mm² double-core sheathed wires should be used;
After the wiring is connected to the terminal block, there must be no exposed parts.
The wiring requirements of the air conditioner power supply are carried out by professional electrical technicians;
The wires, cables and electrical accessories selected in the installation of electrical equipment must use products that have been certified by the state;
Flexible conduits should be used for connecting signal lines, mains power supplies and equipment, but the length should not exceed 1.5m;
Rigid wire nozzles and threading holes should be equipped with retainers, sheaths, etc.
The wiring requirements of the air conditioner power supply are carried out by professional electrical technicians;
The wires, cables and electrical accessories selected in the installation of electrical equipment must use products that have been certified by the state;
The three phase wires (A, B, C) of the three-phase power supply should be yellow, green and red respectively, the neutral wire should be black, and the ground wire should be yellow and green;
After the wiring is connected to the terminal board, there can be no exposed parts;
The wiring requirements of the air conditioner power supply are carried out by professional electrical technicians;
The wires, cables and electrical accessories selected in the installation of electrical equipment must use products that have been certified by the state;
Flexible conduits should be used for connecting signal lines, mains power supplies and equipment, but the length should not exceed 1.5m;
Rigid wire nozzles and threading holes should be equipped with retainers, sheaths, etc.
(12) Master controller
(13) Thermostat
(14) Chain control
Introduction to interlocking control function:
The end of the fan coil unit must be equipped with a linkage thermostat, otherwise an intermediate relay must be connected. Control logic: when one end starts, the linkage switch closes, the circulating water pump runs, and the unit opens, and when all ends are closed, the linkage switch is disconnected, the unit stops, and the circulating water pump stops for 30 seconds.
Introduction to the interlocking control function: when all fan coil units are closed, this switch is turned on, and the unit is shut down; if a user fan coil unit is opened, the switch is closed, and the unit is turned on.
Realization of interlocking control: cascade (or logical cascade) of all user two-way valves or end fans, and then convert them into a switching signal, which is introduced into the EN-SAVE port of the motherboard.
(15) System debugging
(16) Test operation of the unit
1) The test run must be carried out after all the installation has been completed.
2) Please confirm the following items before trial operation, and mark √ box after confirmation.
● The floor heating unit is installed correctly. □ ● The power supply voltage is consistent with the rated voltage of the unit. □
● Correct piping and wiring. □ ● The air inlet and outlet of the unit are barrier-free. □
● Smooth drainage and emptying, no water leakage□ ● The leakage protector can operate effectively. □
● Pipe insulation has been perfected. □ ● The grounding wire is properly connected. □
3) Check that the unit is correct, the unit is powered on, and the time, set temperature, and current temperature should be displayed after the unit is powered on.
4) Drain the air in the pipeline, press the ON/OFF button on the operation panel, and the unit will run at the set temperature.
Check if the following work is completed before powering on:
1. All the water pipes are connected, 2. The power supply wiring is completed, 3. The air duct is connected, 4. The filter is installed correctly.
Power on for the first time to check whether the operating current of the unit is normal;
Whether the function keys of the operation panel are normal;
whether the indicator light is shining normally;
Whether there is any water leakage in the whole heating circulation system;
whether the condensate drainage is normal;
Whether the pressure of the operating system of the unit is normal (the high and low pressure is detected according to the water temperature);
Whether there is abnormal sound and vibration during the operation of the unit;
whether the resulting wind, mechanical noises and condensate affect neighbours;
Whether there is a refrigerant leak.
When the power is turned on, turned on immediately or turned off and then restarted, the compressor with protection function of the floor heating unit needs to be delayed for 3 minutes.
Use:
1. Correctly grasp the operation method of central air conditioning start-up and shutdown:
The correct way to use central air conditioning is to correctly master the operation method of central air conditioning start-up and shutdown. Although the layout of the electrical control panel of different brands of household central air conditioners is different, the general operation method is the same. To turn on the central air conditioner correctly, you should choose the correct windshield. When the machine is just turned on, it should use a high air volume gear, and after a period of operation, when the room temperature is close to the set temperature value, it is changed to a low air volume gear or a medium air volume gear, which can make the machine in an economic operation state and help save electric energy. To turn on the central air conditioner correctly, you can not turn it back on at least three minutes after turning off the central air conditioner, otherwise it is easy to damage the compressor.
2. Set the temperature of the central air conditioner correctly:
The indoor temperature should be set reasonably, not too high or too low, so that all the people in the room feel comfortable. Generally, in summer, it should be 24-28°C, and the temperature difference between indoor and outdoor is 5°C, so that the humidity can be kept at least 50%, so that people and human skin can be kept in the mildest and most comfortable state. Special attention should be paid to infants, school children, the elderly, and the sick, and the temperature should be adjusted appropriately.
3. Pay attention to the airtightness of the room when using the air conditioner
The indoor environment is also an important factor affecting the power consumption of air conditioning, if the sealing effect is good, the air conditioner will quickly adjust the temperature after opening, if the sealing is not good, the cold air continues to lose, the air conditioner has been in the working state, and the power consumption naturally rises.
4. Clean the filter frequently
After the air conditioner is used for a long time, the dust blocks the filter screen, which greatly affects the refrigeration and refrigeration effect of the air conditioner, and consumes electricity. Therefore, it is recommended to clean the filter once every two weeks to prevent smoke and oil mist from sticking to the filter, so as to ensure that the air conditioner blows a healthy and fresh indoor air during ventilation or the next use.
5. There are different modes for properly adjusting the air conditioner
Learn to choose according to different needs. Before going to bed, you can adjust to the "sleep" mode, which can avoid the temperature difference being too large, and can save energy and electricity.
6. Use the central air conditioner correctly, and do not blow the air conditioner directly
Although the central air conditioning refrigeration is very comfortable, you should also pay attention not to blow on the central air conditioner, otherwise it is easy to catch a cold, especially when you are sweating, you must not blow on the air conditioner.
Maintenance & Repair:
1. Repair and maintenance
1) The unit should be maintained by full-time personnel, and the unit should be monitored and maintained regularly. It is necessary to designate a strict post responsibility system and operating procedures, and strengthen regular maintenance and overhaul.
2) The coil should be cleaned regularly 1~2 times a month. Remove the dirt accumulation outside the coil and the scale inside the pipe, so as not to affect the heat exchange effect and ventilation volume.
3) During the shutdown season, the coil should be kept full of water in summer to reduce corrosion, and the water must be drained in winter to avoid freezing and cracking the copper pipe.
4) The motor has been lubricated and sealed in advance before the machine leaves the factory, so it does not need lubrication in maintenance.
5) The evaporator fins can be cleaned with a hard nylon brush, and must be cleaned with a vacuum cleaner before brushing, if there is compressed air, the condenser or evaporator can be cleaned with a high-pressure air pipe.
6) Regularly check whether the return air outlet and air outlet of the unit are blocked by foreign objects, and take out foreign objects to circulate air if so.
7) Pay close attention to the exhaust and suction pressure of the system during operation, find out the cause in time if there is an abnormality, troubleshooting, if you can't judge the cause of the failure, please contact the technical department or contact the manufacturer's special after-sales service department to solve it.
8) Control and protect the equipment, do not adjust the settings at will on site.
9) Regularly check whether the electrical wiring is loose, contact oxidation, foreign matter and other poor contact, and always pay attention to the working voltage, operating current and phase balance. Check the reliability of electrical components in time, and replace failed and unreliable components in time.
10) The air source floor heating unit adopts a high-efficiency heat exchanger, the effluent temperature is high, and after long-term operation in some areas, calcium oxide or other minerals may be deposited on the heat transfer surface of the heat exchanger water side due to local water quality reasons, and these minerals will affect the heat transfer performance when there is more fouling on the heat transfer surface. Descaling must be carried out regularly.
Note: The water supply pipe must be added with a Y-type filter to prevent the condenser or pipeline from being blocked; descaling material: use formic acid, citric acid, acetic acid and other organic acids to clean, and must not use chloric acid or fluoride cleaning agent, because the material of the water side heat exchanger is stainless steel, which is easy to be corroded by it, resulting in refrigerant leakage.
Do not use steam or hot water above 85°C. When the water temperature is higher than 85°C, the supply air temperature becomes very high, and there is a risk of burns. The maximum operating pressure should be set below 1.6MPa.
The power must be turned off before overhaul to avoid danger caused by misoperation.
Filter cleaning: In order to ensure the heating and purification effect, the filter screen needs to be maintained and cleaned regularly.
This article comes from the Internet, compiled and edited by HVAC South Press.