Specifications
68 
In order to purchase HVAC automated zone dampers there are some questions 
that  must  be  considered  before  a  purchase  is  made.  Pick  an  accurate  size  in 
diameter for the damper that you will need. Some dampers come in lengths of 6 
inches and 8 inches. Also determine the automated zone damper variety that you 
want, either normally open or normally closed. Subsequently you need to figure 
out how many dampers you will need and also make sure to purchase a 24 V AC 
power supply and electrical wire. 
To select the best damper for a person‟s residential or commercial unit you need 
to  compare  and  determine  the  function  required  for  each  damper.  Damper 
varieties  range  from  the  balancing  type  or  isolation  type.  An  isolation  type 
damper main purpose is to block air flow in the ducts once the AC unit is on. The 
balancing type damper regulates a certain amount of air flow through the ducts 
which is specified by the control panel from the users input.  The configurations 
or shapes for balancing type dampers come in butterfly or louver shape. For the 
other damper type, the configuration basically comes as a guillotine shape. Once 
all  these  criteria‟s  are  determined,  the  mounting  preferences  need  to  be 
considered. When  placing  the  dampers  in  a  residential  or  commercial  unit  the 
mounting can either by a horizontal installation or vertical installation. Some other 
factors  in  damper  placement  are  to  calculate  the  velocity of  airflow as  well  as 
check the size and shape of the damper. 
Having automated zone dampers in the house is an asset to have because of its 
relatively  inexpensive  cost  to  install,  they  don‟t  consume  a  lot  of  energy  (low 
power consumption), and they are simple to maintain. Automated zone dampers 
also  have  disadvantages  for  HVAC  systems.  These  dampers  are  not  always 
reliable due to the normally open and normally closed conditions for the motors. 
Automated zone dampers control one zone or room in a house, whereas multiple 
zone dampers can control multiples zones of a building. Dampers of this type are 
very  beneficial  because  one  damper  doesn‟t  work,  the  other  dampers  operate 
without any deviation to air flow within the zone. A drawback of the multiple zone 
damper system is that they are less cost efficient and use up more power than 
the regular automated zone damper system. 
2.16 Sensors 
One  of  the  main  essential  components  for  our  HVAC  system  control  that  our 
group will be implementing in the design is sensors. The HVAC system control 
we are building is intended for residential units such as apartments and houses. 
A sensor that we will be utilizing in our HVAC design control measures a physical 
quantity  such  as  temperature  and  humidity;  and  converts  it  into  an  electronic 
signal that will be read by an IC chip in the HVAC control system. These sensors 
will  mainly  be  comprised  of  two  types:  a  temperature  sensor,  and  a  humidity 
sensor. A temperature sensor is an integrated circuit chip that measures ambient 
temperature. These chips  are usually placed on  pre-designed circuit boards to 
accurately read  and  measure temperature for  thermostats  in residential and 










