I have a lab project in which FRP duct will be used for fume hood exhaust. The duct penetrates a 2hr shaft. Per NFPA 91 2004 4.1.12 The duct must be wrapped or encased with a listed or approved material equal to the fire rating of the fire barrier on each side for 10 feet. I would like to use...
I am looking at using plastic pipe to distribute HVAC chilled water through a utility tunnel in a college campus application. What are the drawbacks in using plastic verses steel in a tunnel? What type of plastic pipe is commonly used in this application? The pressure will be relatively low...
I have an existing external steel flue feed from a natural gas boiler plant. The boiler plant is going to be reduced in capacity by 50%. I found by calculating the theoretical draft and flue pressure loss per the ASHRAE Systems and Equipment Handbook that the theoretical draft is sufficient...
I am considering a underfloor air distribution system in a new single story library. The library requires humidification. Has anyone designed a system like this? If so, how did you ensure that condensation or mold growth in the plenum did not occur?
Friartuck,
Thanks for the reference thread. In the thread you and lilliput1 discuss loss coeficients of 0.5 and 1.0 for entrance and exit losses for the equation PD = C x (V/4005)^2. Where can I get documentation on these coeficients?
How would you calculate the pressure drop of makeup air passing through a door undercut and through the gap around a door? I have tried modeling it using the ASHRAE DUCT FITTING DATA BASE, but have found for the small airflows and dimensions of the openings, I get an out of range error. Also...
I am adding a make-up air unit to an existing apartment building. The building has a 2-pipe hydronic system (Simultaneous cooling/heating is not avaliable). How can I condition the outside air without subcooling the cooridor served? There is virtually no load in the corridor. I am...
I am considering allowing grooved piping systems (Victaulic) on a 240F heating hot water system and a 42F chilled water system. What are positive and negative aspects about using this system in HVAC applications? In my city grooved systems are often used in fire protection systems, but rarely...
I need to size a run around coil energy recovery loop to recover heat from a group of fume hoods exhaust ducts and use the energy to preheat my make up air. Does anyone know of a good design guide or program for sizing the coils and flow rates? What is the limiting factor on how much energy...
