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  • Users: cjw81
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  1. cjw81

    Chiller leaking refrigerant

    Leak could be from the chiller tubes as well as any flanges or gaskets. The refrigerant is entrained in the the oil. To release it you need to pull a vacuum in the system you will see thee refrigerant boil off out of the oil
  2. cjw81

    new to a HVAC environment!! PUZZLED.what to do

    Forget about the handbooks, this gentleman is in above his head. His HR department has placed a mechanical engineer in a Stationary Engineer's position. You should inform them before someone get's hurt. Mechanical design and operations two totally different fields.
  3. cjw81

    Operating Room Pressures

    I agree with the above post from GRW, your technician is doing an excellent job for your Facility. He is not hiding anything but giving you a "snapshot" image of your systems at the time he made the readings. These are dynamic systems that open and close acccording to programmed parameters. They...
  4. cjw81

    Pressure Relief Valves.

    Should be at the point of least pressure change in system.
  5. cjw81

    Fail-Safe ventilation

    A suggestion-NYC code - fail safe system in the case of dampers applies to duct smoke - fire smoke dampers that on loss of pneumatic air or the fire panel sending shutdown signal the dampers will always fail to the closed position. For class "E" buildings (Hi-rise) and healthcare the dampers are...
  6. cjw81

    Sprinkler for the HVAC SHAFT

    What shaft are you talking about? My guess is laundry chute
  7. cjw81

    Low water cutoff slow drain test - Section VI vs Section VII

    Are these high (15 psig) pressure or low. Below 15 psig?
  8. cjw81

    make-up air for boilers with variable speed FD fans

    Methinks a closer look at the code would be warranted and remember that the code was written for good reason by reasonably reasonable people. Take a look at the NYC high pressure boiler code and you will see that with an installed economiser will save you 10% by heating the makeup air to the...
  9. cjw81

    adding amines in a steam system

    TBP is on the money - amines when put into a boiler are the only chemicals that leave the boiler with the steam. They are specifically designed to do that and when they go around the system they change the PH back to a neutral (you are hoping for a 7.0 PH (not likely but close is good enough...
  10. cjw81

    aluminum vs copper rotor construction - real world 800 HP experiences

    Don't go near aluminum as far as danger of fire is concerned. It was tried and pretty much shoved down our throats to save money. After some fatal fires it was finally banned. You will hear a lot about special wire nuts and connectors, I would not trust any Al setup.
  11. cjw81

    3 Phase motors on Emergency Generators

    Interesting thread. Concerning smoke, in hospitals NYC we are required to either connect generator to 30 % of the nameplate rating or 50% of connected load. If either is not the case we must connect to a load-bank annually in increments of 30,50,75 and 100% in order to prevent unburned fuel from...
  12. cjw81

    Saving Energy in an OR

    In New York you are under a number of alphabet agencies, such as DOH NYS Department of Health and Joint Commission,along with NYFD, DEC,ECB,EPA,DOB. ect. DOH requires 20 ach, but does not state that I can remember that you can have an "off" period. The only time I have seen that apply is when...
  13. cjw81

    BMS Retrofit payback

    One place to start is to realize just how inefficient it is to produce compressed air. One seminar that I attended claimed that making compressed air for operating dampers and controls is about 10% efficient. Yes that means 90% inefficient. Having been involved with HVAC (mostly in healthcare)...
  14. cjw81

    Dehumidifier

    Heat to 119F and then what? Replace the equipment? Your sensible load from the equipment: 1kw = 3412 btu x 100kw = 341,200 btu. sensible load.
  15. cjw81

    Energy benchmark for Miami

    Yes, mauricestoker that is an excellent reference.
  16. cjw81

    Energy benchmark for Miami

    There are two things you are going to be looking for concerning "benchmarking" One is the EUI-The energy utilization index-the statement of the number of BTU'S OF ENERGY USED ANNUALLY PER SQ.FT. Of conditioned space. Energy defined as ALL types of energy. The easiest way to compare is to...
  17. cjw81

    Chiller load and lift relationship

    Here's my two cents. High lift as my experience is related to high suction lift at the impeller of a centrifugal compressor (300 ton - 134a) This lift can become so great as to damage the impellers and other internal components of the compressor.What occurs is the velocity of the refrigerant gas...
  18. cjw81

    Chiller Selection

    Not such an easy question to throw out there. HVAC68 is hitting the point when he(she) refers to load profile. I have found that spot cooling in a number of critical areas are more common and not so easily answered by a low load chiller. Areas like fire alarm system panels have batteries that...
  19. cjw81

    Is a trap required when useing condensate pump?

    You should show at least a 2" air gap to prevent any back siphoning from condensate to drain. If you are using probes to turn the pump on and off, make sure you keep them clean as shorted probes will keep the pump on and cause a lot of replacements. There are plenty of biocide treatment tabs on...
  20. cjw81

    Bleed off from Cooling tower

    My advice, you should get a professional in to make an analysis of your system. you should get only a licensed guy to perform the work. They should have a pesticide applicators license.it does sound like you have multiple problems with the system. Do not take the possibility of legionella lightly.

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