Usually, this monoblock is located on the roof or near the premises. Sizes of these models vary in a wide range. Device cools or heats the air and directs it into the duct system. Gyms, supermarkets, cafes, railway stations and airports use this type very often. In America, they are also very popular in the residential houses and cars.
Design
This device looks like a big window air-conditioner.
It has a cooled condenser, an evaporator, a compressor and a fan. Additionally, the device may have a mixing chamber for mixing outside and recirculation air. Electric or water heater provides heating the air in the winter.
These devices are divided by operation principle into three main groups:
– models with cooling mode;
– air conditioners with cooling and heating modes;
– devices with gas heating and built-in burner.
Operation principle
Air flow from outside comes through the air intake grate into the chamber, where it mixes with air from the room. The ratio between fresh air and air from room is regulated by dampers. They are placed in the air ducts between the device and each room.
The air then passes through the filter and enters to heat exchanger. Evaporator or condenser provides the function of heat exchange. Accordingly, the air is heated or cooled. Air heating is carried out with the help of water heater or electric heater. Gas models use burner. The air with predetermined temperature is directed into distribution ducts. The condenser is cooled with the help of a special fan and uses outside air. After heat exchange, the air is directed to the street. Modern models control the compressor temperature and regulate it with the help of fan speed. This is necessary in winter in heating mode. Control is carried out with remote control or PC or Wi-Fi. Conditioners of low power often do not have of mixing chamber with dampers. In this case, the mixing is carried out in the supply air duct.
Main technical values
Device performance is from 8 to 140 kW. Air flow rate ranges from 1500 to 25,000 cubic meters per hour.
Optimal mode is automatically selected with the help of smart system. Economic efficiency, low noise level and high reliability provide high popularity of these devices among consumers.
Rooftop air conditioner with gas heating
Gas heating ensures a low inertia due to absence of the heat accumulation. Closed design provides rapid air heating. Gas does not contact with the open fire. Performance in cooling mode ranges from 10 to 480 kW. Power in heating mode varies in the range from 40 to 235 kW.
These models use methane, propane or a liquid fuel. The temperature sensors provide the control of air valves for energy savings.
Control
The electronic control system includes contact panel of switches, a microprocessor, sensor and thermostat to optimize air of conditioner operation.
It provides:
– turning on the compressor for circuits of cooling or heating ;
– ignition of the burner in gas model;
– activation of air dampers for sucking and mixing air;
– control of air dampers depending on the operating mode (cooling or heating).
Noiselessness, compactness, low power consumption, various types of fuel and effective filtering system are the advantages of this type. Portable models of small and medium power are very effective for small houses.
All these key features must be taken into account when choosing the air conditioner.
Today, these devices are also widely used for cooling inside car trailers. The video demonstrates its operation.