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  1. HVAC-Novice

    Turbo Ventilators vs Ridge vent

    None of them will provide any legally required ventilation. Even if at peak sufficient, their operation is entirely dependent on weather conditions (wind, temperature). Ridge vent operates a bit based on wind, but a lot based on temperature differences. You didn't share what turbo ventilators...
  2. HVAC-Novice

    HAP- ROOF ASSEMBLY

    I only want to add, make sure the architect gives you the correct U-values accounting for thermal bridges etc. Cross-reference with ASHRAE 90.1 Appendix A to be safe. I have seen people using an R21 value for a 6" metal stud wall because the 6" insulation add up to R19 plus the sheathing...
  3. HVAC-Novice

    load assumption (on panel level) for receptacle in bathroom (hair dryer)

    I'm in Wisconsin and we use NFPA 70 and SPS 316 I have a project with 12 single bathroom. 4 of them have shower in addition to WC/lavatory. Each will have a receptacle by the mirror. I know each needs its own 20A GFCI circuit. But I wonder how I calculate the load on panel level? There are no...
  4. HVAC-Novice

    IMC Occupancy Classification Art Classroom

    If they use anything with VOC (oil paint, glue etc.)... that is why there is an exhaust requirement. If you are the designer stamping this, you should design it for that.
  5. HVAC-Novice

    Duct Sizing software

    Revit uses static regain https://help.autodesk.com/view/RVT/2024/ENU/?guid=GUID-3D31AB56-ADDD-48F7-AA6F-C63A8BA821BD
  6. HVAC-Novice

    White Rust in HVAC Ductwork, again

    Since the owner lets the contractor do whatever they want, let them. This situation isn't salvageable if these conditions persist. Applying the best material on flaky/rusty duct or paint won't work. In paint and adhesion, surface preparation and conditions are everything. Any product also will...
  7. HVAC-Novice

    PICV Installation for Chiller pipe

    Assuming you mean each branch could lead to multiple AHU/FCU, those added balancing valves would be a waste and just add pressure drop. How is the pump controlled? Are you not using a VFD and pressure sensors? And a PICV is a Pressure Independent Control Valve. Why would you need control...
  8. HVAC-Novice

    Ice Cream Machine

    I'm no ice cream expert. But I doubt there is no equipment available. There are the large commercial ice cream companies that you find in grocery stores and I'm sure they use much larger equipment than you need. Did you talk to all manufacturers of ice cream machines? Are they not able to make a...
  9. HVAC-Novice

    Ductboard Ducting

    Everything depends on the special situation and application. Such general statements without knowing the facts usually are not worth much. At last they should give a reason why they dislike them. If you mean those foam insulation boards used as duct, they sound like a good idea from a thermal...
  10. HVAC-Novice

    I feel like I wasted 2 years — advice from senior engineers appreciated

    I'm not trying to argue your point, but one shouldn't take such legal advice from a 3rd party like a random guy on the internet (I'm random guy as well). Different countries will have very different rules. Usually this should get caught when the visa is issued. The country issuing the visa...
  11. HVAC-Novice

    I feel like I wasted 2 years — advice from senior engineers appreciated

    Assess what happened and learn from it: - don't take visa/work permit advice from random people. Contact the authorities for guidance. Maybe you were allowed to work? Who knows, certainly not random people. - Don't rely on a single person's promise for a future job. Even if they were sincere at...
  12. HVAC-Novice

    VAV box minimum flow setting

    What problem are you trying to resolve? And this needs much more explanation from your side. How does fresh air get into the AHU, is that metered based on measurements? Do the rooms have any CO2 sensors or other means to adjust ventilation based on demand? Are you trying to adjust one or all...
  13. HVAC-Novice

    HVAC

    Definitely hire someone local to look at this. 99.99999999999% of users here would assume CFM in relation to HVAC means cubic feet per minute. Including people living in the metric World.
  14. HVAC-Novice

    HVAC

    You should hire a technician to investigate and take measurements. There is a chance an engineer is required to determine what is wrong and what the solution is. I have no idea what "CFM over amping" means. Too much current at a given cfm? How was it measured and who determined what is too...
  15. HVAC-Novice

    HVAC unit whistling - return duct too small?

    What is actual flowrate? Design in residential often just means someone just looked at a number on the unit to "see" 900 cfm, and attached duct to match the size of the duct connection of the unit. Inefficient fittings (elbows, Tee) likely causes more whistling than just the straight duct.
  16. HVAC-Novice

    Changing from Glycol to Water Cooled Chiller

    IMHO, freeze protection is the only valid reason for glycol. The pH buffers, oxygen scavengers, and corrosion inhibitors can be added to regular water as well. The most important thing you can do to protect from corrosion is to provide good de-aeration and not use open interfaces (e.g...
  17. HVAC-Novice

    Changing from Glycol to Water Cooled Chiller

    So the reason for the need of glycol disappeared? what else changed? This should be possible and performance of the existing system should improve. You have to make sure water in the chiller doesn't get too cold. you have to hire an engineer to analyze the existing system and determine what...
  18. HVAC-Novice

    Plan for renovation project

    You should list the location to find someone to help with requirements in YOUR jurisdiction. It sounds lie whoever made the plans wasn't detailed or accurate enough. during plan review, AHJ can request clarification and changes. So the design team should accomplish to the to satisfaction of...
  19. HVAC-Novice

    Equipment Heat Gains / Diversity During Winter

    Talk to the owner about what their expectation is and what they think when the equipment runs. if there is water, you need to provide heating for at least freeze protection. What about if the equipment is down for repair? Do NOT rely on space heaters they need to plug in. Those are a fire...
  20. HVAC-Novice

    Job interviews not converting into job offers. Need suggestions!

    I doubt companies waste time posting positions if they don't want to hire at all. But there is the chance they MAYBE have budget for a position, and that budget falls apart. For example, a company plans to expand into a new product, but a few months later decide not to. So they don't end up...

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