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  • Users: carlosgw
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  1. carlosgw

    NFPA-13 Sprinklers under exposed flat wood joist framed roof - question

    NFPA-13 Sprinklers under exposed flat wood joist framed roof - question. Low Hazard Correct me if I am wrong: Combustible obstructed construction with members less than 3ft OC – so 130 SF max. But the flow can still be .15 GPM/SF
  2. carlosgw

    Successful stratification strategies for balcony areas?

    Two story buildings with the second floor open to the first. The second floor can get very hot. Esp. in the winter. Do you have successful ways to keep the second floor cool short of cooling in the winter? (cooling while the first floor is heating)
  3. carlosgw

    Smoke Control Design

    Is the following something that can be modeled with available formulas? A building connector that connects two buildings three floors each. An exit from the middle floor. About 550 SF foot print. It has open stairs with less than a foot open either side around an elevator. There is no wide open...
  4. carlosgw

    IMC 2015 and ventilation of dwelling units

    International Mechanical Code - 2015 Ventilation for residential buildings over 3 stories vs. 3 stories and less. The way I read IMC 403.1 is for a 4 story or higher residential building - because it is covered under the commercial energy code and not the residential energy code - is that...
  5. carlosgw

    GPM flow for pump size for low rise standpipes?

    If we were to use a pump for a low rise building with two standpipes: Would the flow be 750 GPM, 1000 GPM,or 1250 GPM? I think 750 GPM with 250 for the two top outlets on the most remote standpipe plus 250 for the second stand pipe. However I and confused by 7.10.1.1 which says 500 GPM at the...
  6. carlosgw

    Small DDC networks?

    Can anyone point me to a good primer for connectivity to small BACnet networks. Small single building networks with just a few controllers. Specifically how and where to make the local work station connection and how/where to connect to the internet for remote access? Can a connection be made...
  7. carlosgw

    Reuse 1964 DX coil?

    Do you think trying to re-use 1964 air handling unit refrigerant coil with new refrigerant is a non-starter because: 1. New refrigerant pressure? 2. other reasons? Assume there is no information on the existing coil available - which would be actual case.(other than size and connected...
  8. carlosgw

    Office humidity complaints

    North east - hot fairly dry summer Existing building newly renovated last few months. Office space with rooftop units with gas heat. Occupants complaining about musty smell and humidity in in the 60% range. Space maintained at about 74 deg. RTU discharge temperatures are low 48-49. So they...
  9. carlosgw

    Covert DX coil from R22 to R410A?

    What are the issues with using R410A in a coil originally designed for R22? My specific application is a 2 circuit 15 ton (2 7-1/2 ton) air handling unit coil.
  10. carlosgw

    Refrigerated work area design

    I want to look into what it takes design refrigerated (occupied) work space (2,200 SF @ around 40F meat processing for example). As a starting point what equipment is typically used.(northern US ventilation and cooling, probably don't need heat)
  11. carlosgw

    Add heat for ground souce heat pumps?

    Has anyone run into a situation where the installed wells (or ground loop) was insufficient for the heat add for a ground source heat pump system? (northern climate) What was done to rectify? I'm looking at a small building that has been installed for over ten years but just does not heat well...
  12. carlosgw

    CPVC for a hot water heating system?

    Have you used CPVC piping for a baseboard or fintube hot water heating system? (design temperature of say 170 deg)
  13. carlosgw

    Dryer Booster Fan?

    I thought a typical residential type clothes dryer had a air flow of 150-200CFM. But the booster fans I have found look like they have a capacity of more like 100-150 CFM (Fantech). Has anyone used a booster fan?
  14. carlosgw

    Coefficient for air flow through a hole (in a duct)

    Anyone have any data for holes in ducts? For example say a duct with -.25" and a 1" diameter hole. What would the air flow be?
  15. carlosgw

    Sprinklers above a suspended ceiling when ceiling does not cover room?

    Out of control architect: An open office space with partial suspended ceiling (or very large ceiling clouds). One space has a suspended ceiling for about 80% with three areas open to the deck above. The other has maybe 70% ceiling at different levels (picture a rectangle with a 9’ ceiling in the...
  16. carlosgw

    2012 IECC and water source heat pumps

    The way I read 2012 IECC C401.2 (which is the economizer requirement) is seems to preclude water source heat pump systems unless the building is small (<300MBh) or economizers are put on the heat pumps. True? Or can someone set me straight?
  17. carlosgw

    Uninsulated exposed duct - where is it OK

    Speaking of regular HVAC systems. Rule of thumb is that insulated ducts are OK if exposed in the conditions space. What is your experience? The concern is condensation. I am in northern USA. I would never use them in restaurants and bars. I had an issue one in a retail space. It was a building...
  18. carlosgw

    ASHRAE 62.2 ventilation equation?

    Can someone give me the whole house ventilation equation from ASHRAE 62.2-2010? (IP version)
  19. carlosgw

    Hot water bypass system

    Does anyone make a simple packaged pressure bypass system for hot water heating systems (bypass loop when all or most control valves are closed)?
  20. carlosgw

    ACCA Manual J load program?

    Can you suggest a load program that is ACCA Manual J based? A plus would be output that is easily used for Energy Star certification or LEED for Homes certification. Another plus would be a program for which the directions can be easily changed (e.g. for apartments with the same floor plan that...

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