Unit Heater

Key points in choosing unit heaters :

In general, unit heaters are used for heating purposes in factories, workshops, warehouses, malls, etc. They come in wall-mounted, free-standing, and industrial types and are used in projects featuring a central boiler room (with hot water or steam). This excludes electrical unit heaters that operate without a central heating system and via electricity. Each unit heater is supplied with hot water or steam via the pipes laid from the central boiler to the hot water or steam coil of the unit heater. In order to calculate the heating required for a hall by a unit heater, we need to consider the dominant temperature of the climate, exterior design temperature in winter, size and utility of the hall (interior design temperature), materials used in the building, etc. To do so, it is recommended to predict 240–400 BTU of heating energy per cubic meter of air in the hall.

Benefits of unit heaters :

1. No separate heating system required;
2. High heating capability;
3. Space efficient, especially with wall/ceiling-mounted models;
4. Better distribution of warm air;
5. Quick heating;
6. Vertical and horizontal installation and air output.

How to select unit heaters?

A.The type of heater fluid (hot water or steam) and the kind of unit heater (wall or ceiling) should be attended to before the selection of heating capacity, aeration volume and motor power.
B.For cold climates, 400 btu should be considered per cubic meter of space per hour. For moderate regions, about 250 btu should be considered per cubic meter of space per hour.
C.Considering that the fan of unit heaters are noisy at 1400 round per minute, it is suggested to order two-phase motor or 900 rpm motors with higher heating capacity. 

Parts of unit heaters :

• Cubic-shaped body of the device, which is usually made of steel plate
• Hot water or steam coil with heat exchange fins that transfer water or steam to the unit heater.
• Electromotor, which is responsible for moving the aeration fan axis of the unit heater. Single-phase or two-phase electromotors can be used according to the design and construction of factories.
• Axial fan, which is in fact the same as aeration fan of unit heaters. It receives air from the back of devices and passes it through the coils and heat exchange fins of hot water or steam, and then sends out the hot air from the front of unit heaters.
• The air blades, which are installed in front of unit heaters and are able to direct hot air out of unit heaters.
  
  

Function of unit heaters :

After the entrance of hot water or steam as the energy carrier fluid to the fin coils of unit heaters, air is passed through the coil and fins and its temperature is increased. Then, air is sent out through axial or propeller fans to heat the place.

Hot water or steam coils of unit heaters might have one or two rows. Note that you should announce if the input and output pipe of the unit heater coil is at left or right before finalizing your unit heater order.

Turning on and off and changing motor speed of unit heater fans are done through a thermostat installed at a height of 140 cm from the floor away from hot air of unit heaters or direct sun.

The wind throw and the output air of unit heaters are different based on their capacity and motor power. However, the wind throw and effective heating of unit heaters are generally 8-20 meters.

If you are using steam unit heaters, note that the heating of steam unit heaters are directly related to the input steam pressure to unit heater coils. In other words, if the input steam pressure is 5 psi, the heating of the unit heater is much less that a unit heater with an input steam pressure of 15 psi. Thus, pay attention to the steam pressure available for the heating while selecting a steam unit heater.

 Unit Heater Installation Tips :

A.Base on dimension and weight, unit heaters are generally installed on frames made of steel t-profile or steel angle with size 3-5. The proper height for the installation of wall unit heaters is 2.5-3.5 meters (based on unit heater capacity and installation height).
B.In hot water unit heaters, the input hot water pipe is placed down the unit heater; and in steam unit heaters, the input steam pipe is placed up the unit heater.
C.It is mandatory to install an automatic air release valve in the direction of returning water of hot water unit heaters.

To calculate the hot water discharge, divide the hot water unit heater capacity (BTU) by 10000 to get the G.P.M of hot water in circulation. You can contact the experts of Damatajhiz Company to receive more consolation.

Placing an Order and Warranties Unit Heater :

• Offering best price guarantee for all products, the prices for Unit Heater presented by DamaTajhiz are up-to-date and discount-included (see Best Price Guarantee at DamaTajhiz.com).

• Find the technical information you need for comparison and purchase for several models of Unit Heaters from reliable manufacturers at DamaTajhiz.com, under Unit Heater category.

Efficiency is our motto, your profit our priority

1 Atm = 14.7 PSI
1K Cal = 4 BTU
1M³/hr = 0.588 Ft³/ min
1M³ =35.15 Ft³
1m/s = 196.85 Ft./min
1Ft./min = 0.0051 m/s