Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. seanhkim

    supply air damper response time

    Does anybody know how long it takes for a supply air damper move after it takes an actuation signal? Let's say, now it is 70% open. It needs to open up to 80%. How long it would take? I just need some experimental values from your experinces. Thanks.
  2. seanhkim

    Pressure control in a lab by exhaust damper

    A negative pressure is usually kept by modulating exhaust damper in a lab, instead of supply damper. Is there any reason for that? In my sense, increasing exhaust air volume has the same negative pressure effect in the lab compared to decreasing supply air volume. If all of exhaust dampers in...
  3. seanhkim

    Time to change pressure in a VFD fan

    I need to know how long it takes to change from one pressure point to another pressure in a VFD fan. For example, from 250Pa to 500Pa. My scenarios is once the fan gets signal to increase pressure differential from the controller, how long do I need to wait until the pressure level gets to the...
  4. seanhkim

    Elapsed time for air supply

    I wonder how long it takes from when sensing a change in air pressure untill when increased air volume blows out of the supply vent. Let's say I have an air pressure sensor dectecting a change of air pressure. Sensor reading is under requirement such that I need more makeup air. Signal...
  5. seanhkim

    Airflow balance in hospital

    In a hospital floor I'm evaluating on, there are 25 patient rooms. Two of them are negative pressure rooms, and other are general patient rooms. According to the guide, negative pressure rooms have -0.0037"W. To make the negative pressure, return is set to 400cfm and supply is set to 200cfm. For...
  6. seanhkim

    Reverse flow in isolation room

    I'm evaluating isolation rooms in a hospital. The pressure difference between the room and the corridor is -0.0037"W (negative pressure) when the door is closed. But when the door is open, the pressure difference is getting reduced and surprisingly the pressure difference becomes postive. The...
  7. seanhkim

    VAV used as CAV in hospitals

    I'm searching cases that VAV in hospitals are actually used as CAV because of several reasons. The biggest reason would be concerns of loosing pressure relationship between rooms in case of VAV. But is it the case happening in most hospitals? Is there any way to assure constant pressure...
  8. seanhkim

    Type ERW or Type S pipe

    Hi I'm a graduate student who studies HVAC systems in hospitals. As I saw your replies for my stupid questions several times, I really want to ask you something about CAV/VAV in hospitals. Instead of making it open a question, I wish I can hear your personal opinions. If you allow me to contact...
  9. seanhkim

    sequence of operation - heat pump and FCU

    Hello experts: I'm writing up the sequence of operation of heat pump and FCUs. Since it is the first time to write this kind of documents, I have no clue to start. I appreciate if anybody can explain how these work when heating mode and cooling mode. Especially in terms of control variable...
  10. seanhkim

    Humidity control for individual room

    I have a case that a single duct VAV system serves several rooms, which means reheat coil is inside of the terminal box. One of rooms in the zone has high humidity due to internal process. But other rooms are OK. Without dedicated dehumidifier, how can I reduce the humidity of this room? First...
  11. seanhkim

    CV and VAV in hospital

    I looked up CV and VAV choice in hospitals from va HVAC design guide as atlas06 suggested in eariler threads. And I found that corridors, patient rooms, kitchen/dining room and treatment rooms are recommended to use VAV. But others are recommneded to use CV. The reason I assume is that others...
  12. seanhkim

    Hospital HVAC failure cases

    Am I able to find real cases where infection problems have happened due to impaired pressure relationship or due to sluggish pressure relationship restoration? How is the performance of PID controller in the VAV terminal unit? Does it work fast enough to cope with changed pressure requirement...

Part and Inventory Search

Back
Top