I believe you have a simple membrane penetration of a rated assembly. This is common in multi-family high rise buildings. At most, you need a RD at the point of communication with the occupied space. You will find this with ceiling mounted exhaust fans which have a RD above the ceiling grille...
A plate and frame heat exchanger coupled with a hot well / cold well on the cooling side with chiller is the most common way to do this. The cold well side is cooled via fluid cooler or tower as the tower sump can be dry when located indoors. Indoor sump will eliminate PG/EG as the cool source...
Two (2) sets of twinned furnaces (bottom or both side rtn) or 2 Reznor/Sterling/Modine roof mounted indirect furnaces with Two 5 ton ACCUs off to the side. Stage the ACCUs. Captive air does this with multiple 5 ton ACCUs ontop of the AHU. 5 ton single phase are very poor at starting. This all...
As others have stated, you need to define the inlet and outlet steam conditions. You only advised inlet pressure – superheated? At saturated entering and 14.7psia leaving, you can calculate a Cv of both control valves based upon a “critical” valve. Size main line piping for DP at the mass flow /...
You will need a little more information on the glycol process to do a selection. I gather the small feed was selected as the fine temperature control to give the CV improved LWT control. I suggest you select your valve mfg rep and have them help with the application of body(s) and actuator(s). A...
If the roof assembly is not rated, then you need a fire damper at the OA duct penetration at the bottom of the rated shaft. A SFD could be applied but a FD with the correct rating should meet your requirements. I have seen a roof rating issue such a parking garage in which the shafting must be...
The high OA flow is driving the load. You are correct with the design condition of 107F DB. I review the Air System Design Summary output to see which parts of the envelope, internal loads, fans/pumps or ventilation which are driving the load in terms of SHG and LHG to the zone. This design...
In a classical VAV system, central AHU heating requirement is calculated from the greater of 1. Supply air tempering requirement or 2. Morning warm-up heating requirements. These values are found in your load calculations.
You will need to utilize an engineer with experience in design of duct systems. SMACNA and ASHRAE have duct design guides and apps that present flow vs. dp. I would simulate the system with a load estimating software based upon fan eff. and power cost. You will end up with a delta operating...
The type of damper you are looking for is called "bubble tight". Read the application guides for construction details and actuator applications. http://www.greenheck.com/products/detail/69
You need to look at the complete system to evaluate the damage. I ask what is the end game? Are you trying to check the fan or go after others that are responsible for this design? As others pointed out, an offset of 2 elbows is not the only issue. Entry fittings into and exiting the elbows...
Cover the basics first with known data. 1. Hire a balance contractor to measure the condenser water flows. Inspect all strainers and pressure gauges first. Verify sump inlets and header nozzles. Run thru combination of pumps. The 6” is undersized for 1350 gpm - tower isolation vlv may not be...
Bos88, I agree 2700 gpm is needed but read the second paragraph, the wording sounds like 2 single cell units makeup to be the “tower” with motorized valves. With a common header they should have stated total flow.
Re-reading your posts and documents, you have two nominal 450 ton towers with two 450 ton chillers and one common condenser water system at a total of 1350 gpm. It looks like the single cell tower was run at 1350 gpm. You have a condenser water issue. Should the tower data have been run at 675gpm?
Purchase a Flir or Fluke IR camera. Reading flow on the little fans is impossible outside a lab. Cables and racking will cause your test methods to fail. Heat and dirt is the failure means, don't chase the heat removal medium but look at the heat via IR. Cards, drives, inlet / outlet...
