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  1. nuuvox000

    What literature will teach me how to size medical gas systems?

    I've been sizing domestic, hydronic, sewer, and natural gas for years but this is the first time I've had to size medical gas. Having a bit of trouble finding the right resource. Thanks,
  2. nuuvox000

    Supply air duct

    If it was already functioning just fine with the airflow before this, a couple of bends isn't going to change that.
  3. nuuvox000

    Pump Upstream Higher Pressure Issue

    Ah, that makes sense now.
  4. nuuvox000

    Pump Upstream Higher Pressure Issue

    One more thought: I wonder if I should put the circuit setter next to the open/close valve to make sure we're not sending way too much water from the supply to return pipe. Like so:
  5. nuuvox000

    Pump Upstream Higher Pressure Issue

    Agreed on that combined system. I don't know who thought all of that extra work and maintenance was going to be worth it, just to avoid running an extra pipe or two throughout the building.
  6. nuuvox000

    Pump Upstream Higher Pressure Issue

    MTES93, that's fantastic, thank you for that! Forgive my ignorance but what is that symbol you have on there with an "M" inside and two antennae? Here is my latest revision.
  7. nuuvox000

    I need help about running multiple fans

    This might help you understand a bit better: https://www.engineeringtoolbox.com/pumps-parallel-serial-d_636.html
  8. nuuvox000

    Redesign for Latent Load

    It sounds like the AHU's were designed to cool down the air but weren't necessarily designed to dehumidify to certain requirements. If that's the case, then you can either cool the air down further (people will likely get uncomfortable) or install a system designed to dehumidify the air. This...
  9. nuuvox000

    Recording Studio Airconditioning Controls Strategy

    What's the total load? If they're set on packaged RTU's for instance, you can just get a few 3 ton RTU's to break up the zones and loads. I do this all the time because packaged RTU's are just so much cheaper than other systems. They're also very simple to control and maintain which is a huge...
  10. nuuvox000

    Pump Upstream Higher Pressure Issue

    Yes, it definitely eats their system; they are using it for drinking, bathing, etc. Unfortunately, the pressure is not quite high enough to do it with a modulating valve. The on/off valve is controlled by the pump; if it runs, the valve opens, if it stops, the valve closes. The variable speed...
  11. nuuvox000

    Pump Upstream Higher Pressure Issue

    Yes, that's correct. All the pumps, coils, valves, etc on the bldg side are potable water rated. It's pretty common in this one particular city we work in.
  12. nuuvox000

    Pump Upstream Higher Pressure Issue

    That was a great idea though, something I didn't think of. Ok, looks like the supply pressure is 80 psi because it's a domestic/hydronic combined system on the building side. I just had a thought, I could probably use a PRV before the pump to take the pressure down and that would be a lot...
  13. nuuvox000

    Pump Upstream Higher Pressure Issue

    My conclusion so far is that FacEngrPE is correct about the cavitation issue. I see our options as injecting the return water back into the supply (robbing from it) or providing a pressure sustaining valve ($). Option 1 will require a full bldg review with the maintenance crew there and option 2...
  14. nuuvox000

    Pump Upstream Higher Pressure Issue

    Sorry all, not ignoring you, just had to meet a deadline on another project. Here is the full diagram. This is a case of a PM telling me, "I already ordered the equipment and some of it is on site; can you just draw up a diagram to make sure I didn't miss anything?". Basically the pumps and heat...
  15. nuuvox000

    Pump Upstream Higher Pressure Issue

    Thanks for the great responses. I didn't think about cavitation, thanks for that. The CV control valve is just a simple open/close valve; opens when the pump runs and closes when the pump is off so that water doesn't flow through the heat exchanger when it's unwanted. The pump is controlled on a...
  16. nuuvox000

    Pump Upstream Higher Pressure Issue

    This is how I'd like to pipe in a new heat exchanger into the existing building system. The pump shown is variable speed. I'm concerned that the higher pressure HWS upstream water will push more water through the pump than required when the pump is running at low speed. Do you think this will be...
  17. nuuvox000

    Repair Garage - Overhead Door Make-up Air

    Opening it is one thing, but what about closing it? How do you know that vehicles and people are not going to be smashed when it closes? Also, seems like a security issue if it's opening without someone actually activating it themselves. I would not do it myself.
  18. nuuvox000

    Need more $$$, thinking about changing careers or doing side work.

    drawoh, thank you for bringing that up. I would actually only do any side work after getting explicit and written permission from my employer; in my state, you can lose your license for doing side jobs that are not approved by your primary employer. In my case, doing anything residential would...
  19. nuuvox000

    Need more $$$, thinking about changing careers or doing side work.

    StrucPatholgst, sorry for the late response, I wasn't notified by email like usual. Those are really great ideas and I thank you for letting me in on your information. How did you get started doing Manual J's? I've done a few over the years for my bosses friends. I guess I would just start...
  20. nuuvox000

    HVLS fans in the summer?

    I've seen that manufacturers tout HVLS fans for summer use by saying they have a cooling effect that can make people feel 10 degrees cooler than without it. But wouldn't it also destratify the warmer air near the top of a warehouse and bring it down to floor level? Pretty much cancelling out the...

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