GT-EGR:
Thanks so much for the response. I'm trying to get as much input as I can.
I was thinking last night about it and thought that thermal dispersion controls would really help ensure the proper amount of building pressurization air regardless of turndown. Just wonder if they're...
I'm used to designing variable volume systems.
I have a food production facility with a warehouse/loading dock side of house, a large area with a lot of steam being used, and another large area with a lot of sensible heat on one side of the room - an area with insulated, cold equipment - and...
Seems to me that there is no consensus on this one. I'm selecting slot diffusers for an exterior zone with a large amount of glass. In addition, the ceiling height is 8'-6", with occupants sometimes directly up against the glass. ASHRAE (I think it's in "Systems and Equipment") says to select...
So - The unit is running at approximately 45% outside air. I asked this question because, in the past - I ask for testing on an existing unit, and I rarely see anything that is crazy high or low from a pressure perspective. For this test, I had all the boxes placed at maximum to see what the...
The option that comes to my mind - Packaged units with terminal reheat, but grouping some of the classrooms with the same exterior exposure directions. If there's a kitchen, you'll probably need to keep that separate - exhaust requirements, varied exhaust? So maybe 3 or 4 rooftop units. I...
What do you typically look out for when looking at the pressure profile of a unit?
I have a pressure profile for an existing unit that - during testing - generated a much lower pressure than expected at the intake of the unit. The pressure measured was substantially more negative than the...
I appreciate your feedback, EnergyProfessional. I understand the energy total standpoint, but are you (or is anyone else) aware of a situation where there were temperature control issues after using a larger-than-required reheat coil? Why all the caution regarding laminar flow in the coil?
With such a low LWT, aren't you "choking it off?" Different texts warn you about thermal shock to the boiler, laminar flow through the coil, as well as coil capacity drop off. But if the overall system is designed to a 20 degree water delta T, and relatively few instances where you're greatly...
I guess the real question is, all other performance parameters being acceptable, what situation is preferable for scheduling your control valve and coil: 1) That the LWT is what you want (in my case LWT=160) - but the LAT is beyond what I need, or 2) That the LWT is much lower than desired, but...
I am trying to become better at hvac coil selection. I've recently run into situations where compromises have to be made, and I'm unsure of what my priorities should be in the final selection.
I was trying to select a heating coil for an FCU with approximately 4,000 cfm, EAT=55, LAT=85. I had...
