- The unit heater cases are manufactured from the finest steel in home appliance industry (ST14)and by specific molds and fixtures.After passing through the decreasing, phosphating, and rinsing paths, the parts of the unit heater cases enter a drying furnace. Once dried, the parts are electrostatically covered with alkyd-melamine resin (powder coating) and curded in the 200°C furnace.
- In order to prevent vibrations from the electro-fans to fan cowls and casings and minimize the apparatus vibration, a separate supporting is designated for installation of electromotor, which results in Sabafarin's unit heaters being vibration-free.
- The coils in hot water unit heaters are manufactured from copper tubes Ø 5/8" with wall thickness of 0.635 mm. The utilized fins are aluminum fin plates (12 fins per inch). The fins are manufactured by C.N.C. fin press. The copper hairpins are also bonded in C.N.C. bending machine . The connection between copper tubes and aluminum fins is granted by vertical N.C. expanders. The coils in steam unit heaters are manufactured from copper tubes Ø 5/8" with wall thickness of 1 mm or carbon steel seamless tubes Ø 5/8" with wall thickness of 1.5 ~ and ASTM-A-179 material. The utilized fins are aluminum fin plates. Tubes with spiral fins are never used in manufacturing of unit heater coils due to their low heat transfer surface area and weak connection between fins and tubes.
- Stainless steel tubes could be utilized in manufacturing of coils upon customer 's request.
- After being manufactured, hot water coils are hydraulically tested under 10 Bar pressure.The testing pressure for steam unit heaters is 30 Bar. Please note that all unit heaters have 2-row coils, except type 200, which has 3-row coils.
- The electromotors used in Sabafarin unit heaters are usually 2 speed single phase (900-1400 R.P.M) which are high-quality motors. Three phase or anti explosion electromotors (which are used in the environments with explosive gases)could be used upon the customer's request.
The utilized fans blades are from aluminum with thickness of 1.5 mm and hubs are from steels heel metal with thickness of 2 mm. The fans are completely balanced both statically and dynamically.The fan blades are also designed in a way that have an extremely low power usage.
The deflection louvers of Sabafarin unit heaters are adjustable which could be adjusted to direct the hot air to the desired location. In places which need a higher air throw, special deflection louvers with adjustable levers and in form of air foils ( flow optimizer ) could be used, which are able to force the air up to twice the usual deflection louvers and thus increase the heating efficiency. These louvers are placed on the unit heaters according to the customer s request. The performance of the flow optimizer is as follows: By locating these louvers on unit heaters, the directed air flow is generated, which increases the leaving air flow and decreases its mean temperature. The later results in elevated unit heater throw, decreased energy consumption and a more pleasant room temperature. The specific type and shape of the flow optimizer louvers draw the air around them towards the hot air leaving the unit heater ( Fig. 1 ), which results in increased volume of air, decrease temperature and enhanced throw.
The below figures display the optimized energy consumption in unit heaters with standard & flow optimizer louvers ( Fig. 2 & 3):
(Fig. 1) -The Induction Flow Optimizer Jetstream
(Fig. 2) -The Induction Flow Optimizer Jetstream
(Fig. 3) - Air Flow Stream (With Flow Optimizer Louver)
Various types of Sabafarin unit heaters are identified with the following numbers and letters:
The data in the following table are tabulated based on the inlet air temperature of 16°C, inlet hot water temperature of 90°C, and outlet temperature of 80°C from coil. The unit heaters should Repositioned in a way that the outlet hot air could cover all the desired areas. Also the air throw in the environment is calculated exclusive of other possible air movements.
a) Honzontal Discharge:
b) Vertical Discharge:
Piping System in Vertical and Horizontal Unit Heaters:
The piping procedures could be found in the following figure. Choosing of the best piping method is based on their performance and also the location of the feeding source. The size of tubes, valves, filters, and steam traps should be determined according to ASHRAE standards and manufacturing company information. The best way is to consult with a professional engineer in this field who could figure out the sizing of the required instruments and minimize any possible future risk.