There are several types of Air conditioner system, from split units, ductable systems, to central systems like VRV. Each of these systems require a closed cycle of refrigerating gas, during the cycle the gas applies to the compressor and expansion valve. The pressure difference causes different temperatures. During pressure change it occurs condensation of moisture in the air that needs a drainage system. Also Internal and external units require power to work. Each of the internal and external units require refrigeration gas, drainage and electrical pipelines. This post will discuss how to install air conditioner pipelines.
Installing A/C Internal Unit
Internal units vary in mounting method, either wall, floor or ceiling mounted. Wall and floor mounted internal A/C units installed at walls, where wall mounted level usually 230 cm above FFL. It’s necessary to ensure it will not intersect with any other works, and leave at least a 15cm from top of A/C to the ceiling level for installation. The floor mounted A/C usually installed next to a wall, therefore installing the pipelines level at 50 cm from FFL.
In a wall mounted A/C unit, we prefer to install air conditioner pipelines inside a plastic in-wall box that could cover. So in case of not installing the A/C unit, the box will be covered with a good appearance. Otherwise the pipelines will appear in bad looking as shown in the following photo. We recommend using an electrical box, in size of around 30×15 cm. Inside this box, drainage installed at the lower edge, to prevent water leakage. For most of A/C internal units, where refrigeration pipelines designed to install at left hand side and few small size models are designed at right handside. Therefore install at the left hand side or check the A/C producer or supplier. On the opposite side of the refrigerating pipelines install the electrical pipelines.
For ceiling mount internal units like cascade, concealed and central units where it is usually hidden inside the false ceiling. no need to install the pipelines in a box. Selecting the place of the A/C ceiling internal unit is an important role. Install the ductable internal unit in the corridor, dressing room or any room that noise does not affect its function. Also installing the A/C device at the toilet, laundry room or any room that has a high humidity could reduce the device lifetime.
Installing A/C external unit
Architects have to design areas for external units that don’t harm the elevation design. This area has to be accessible for maintenance with good ventilation. I like to make it next to the toilet wall, to prevent A/C noise for other rooms. In this case the design the toilet windows that allow passing the external unit and a maintenance guy. I prefer A/C areas that have slab, to accommodate A/C external units and places for maintenance guys to stand during maintenance. In some cases when architects can’t leave the slab, a steel holder could be installed to carry out the external unit. In this case the holder needs to bolt to a concrete and not a cement block. A concrete like lintel or slab for better bonding with the wall.
A/C Refrigerating Pipelines
Refrigerating pipelines connecting the A/C internal unit to the A/C external unit. The refrigerating pipes are made of brass that have a thermal insulation layer that keep the gas temperature. The brass refrigerating pipes is a closed loop, and any weak point will cause gas leakage. Once there is gas leakage the air-condition will not work well. Also refrigerating gas like R22 will harm the environment, it’s better to select A/C that uses R410A eco-friendly gas. Therefore notice few point that could acure gas leakage:
1- Thicker brass gas lines are better than thinner ones.
2- try not bending the brass pipes, or bend using a large radius bend.
3- Use one continuous pipe, prevent welding. If you have to weld brass pipes, choose the welding placement that is reachable for maintenance.
4- Try to place the refrigerating pipe away from any work that needs drilling. To prevent drilling after installing air conditioner pipelines or mark the placement of the brass refrigeration pipes.
5- Design the pipelines in a way you could change them easily. Like installing them inside the false ceiling or inside flexible pipes similar to water supply PEX system.
The brass refrigeration pipes size depends on the product. Where each producer recommends a certain diameter for the system depends on A/C capacity (BTU), where each line contains two refrigeration pipes. Notice that BTU is British Thermal Unit, and each 12000 BTU is 1 Ton A/C. Also design the shorter refrigerating pipes to prevent gas pressure loss. Therefore prevent vertical pipes, where the head pipes will lose the gas pressure.
A/C Drainage Pipelines
The A/C drainage pipes have to be installed to rainwater pipes (RWP) to prevent sewage smell. When installing a sewage system either SWP or WWP will cause a bad smell especially if it’s not connected to a gully trap. A/C drainage pipes can be either PVC pipes or flexible. PVC pipes are better than flexible because PVC pipe’s slope will slide water or dust toward the RWP unlike flexible. Where water and dust could stay at flexible lines accure water leakage or blockage of the drain line. Therefore use PVC pipes in diameters of ½” or ¾” that slope toward RWP – rainwater pipes -.
A/C Electrical Pipelines
Supply power to A/C by using pipelines from distributed board (SDB) to A/C internal and external units. These pipelines will host the electrical wires, most common 2.5mm wires are used for split units. It requires wider wires for the central system, depending on the product. Electrical lines for air conditioning systems require few tips to take in consideration while designing the system. In the SDB for better control, install a CBM for each room air-condition. This method will make the ability to add solar system or UPS system -backup electricity network-. For the internal unit install a switch with a light indicator next to the A/C internal unit, to monitor when the A/C is on and could turn it off in emergency cases. For the external unit install waterproof MTS -manual transfer switch- for better control during external unit maintenance.
In the last several years, an A/C inverter system has arrived on the market. The inverter system is perfect for the solar system and for electrical generation supply. Normal pumps require high electrical current to start working then it reduces gradually. The inverter system starts working using small electrical current then increases smoothly. Inverter pumps will save the life of UPS battery banks. Once the inverter system is related to pumps, so it could be an inverter refrigerator, water pumps and many other applications. Another point to take in consideration is inverter A/C requires more time from starting A/C until reaching the room requires thermal condition. This because inverter air-condition increases the electrical current gradually, that means the performance of air-condition increases gradually. Generally either a normal system or inverter system it requires the same install of Air Conditioner pipelines.