I'm trying to calculate the thrust load on a 3" HPS elbow, Sch. 80, welded construction, for an underground direct-bury application. I don't typically work with steam, so I'd like a check of my numbers.
This is a 3" branch pipe off an 8" HPS main at 175 PSIG. Design velocity is 5000 FPS.
The...
We are renovating an existing greenhouse. The researchers moving into this renovated space require evaporative cooling. This greenhouse, which is divided into two 20' x 33' sections, will have a very short pad-to-fan distance (side wall to opposite side wall). Both ASHRAE and the Nat...
I'm working on a revision to a dean's office at a local campus. The main air handler is a CV unit with no excess capacity. The new office layout will require additional cooling airflow than originally designed. What are my options to improve this situation? A fan-powered box would draw warm...
I am a new facilities engineer at a local university. We have a system (designed by an outside consultant) that uses flow control valves on VAV fume hoods. The hoods are used extensively for acid digestion (boiling off hydrochloric acid, hydrofluoric acid, nitric acid, OR hydrogen peroxide)...
I recently started a new job, where the AutoCAD software defaults to "AutoCAD Architecture" instead of the plain vanilla AutoCAD (v. 2012). As I am a mechanical engineer and not an architect, I prefer the familiarity of the basic AutoCAD layout.
I discovered by selecting OPTIONS -> PROFILES...
I have a client who wants to run a 5000 PSI compressed air line around the perimeter of a shop. Airflow of 50 CFM max are expected. Can anyone direct me as to what materials may be suitable? I'm looking at a 1" Sched. 80 welded steel pipe, but I wanted to check other options. Are...
I am designing an exhaust system for a small room (~400SF) containing a closed, dilute sulfuric acid system. Airflow is approx. 6 ACH. Is galvanized (w/high-performance paint) the cheapest option, or would a plastic duct be more chemically resistant?
I am running TRACE 700 v6.0 and am struggling to meet the ASHRAE 62.1 outside air (OA) values within my heating outputs. To correctly set the OA values, I have input the COOLING & HEATING ventilation values as the min OA values calculated using 62.1(from the CREATE ROOMS:AIRFLOWS tab). The VAV...
Here's an easy one for a Friday...
Can anyone tell me what the "ci" used in Table 5.5-4 means as listed after insulation R-values for Mass Walls, Above Grade?
Thanks in advance.
I am looking for representative data for a big rig-type engine. Specifically, I need the exit temperature at the end of the exhaust stack for a capture velocity calculation.
Engine manufacturer data is not easily available, so I need general figures. A quick search of earlier posts yielded...
Does anybody know of an active forum for TRACE 700 users? I am looking for a users group that can help me move from beginner to more advanced user.
Thanks in advance.
I am looking for ideas on how to effectively condition (ie. cool) an admission/access building dedicated to turnstiles alone. Access will be quite frequent, so infiltration/exfiltration is high. Are air curtains necessary to maintain a comfort zone, or would perimeters diffusers (around the...
As an amateur woodworker on the side, I was pleased when my next work assignment was to design a dust collection system for an industrial wood shop (Maybe this will inspire me to move beyond the shop vac in my garage). However, since I am new to the HVAC design world, I've got a few questions...
We (an AE firm) are compressing our office "real estate" to accomodate a new lease. I need to organize the existing reference documents (State & National codes, standards, etc.) for each discipline and collect all project materials in a central location... none of which is done now.
I'm...
I am looking for a general rule for "thorough" mixing of outside air and return air prior to entering an air handler. The air handler in consideration has no mixing plenum, so this needs to happen upstream. To keep cost down, I would prefer to accomplish mixing without addition of an "air...
I'm looking for a simple decision tree for HVAC system analysis using ASHRAE 90.1-2001. Does anyone know of such a creature? A search on Google was fruitless.
TIA.
In looking at diaphragm expansion tanks for a hydronic chilled water system (glycol), the standard tank precharge (air side) is 12 PSIG.
What happens when the pumps are active at, say 40 PSI? Does the tank bladder collapse?
The customer wants to build some reserve into the tank to allow...
I am trying to calculate the thermal resistance of a ceiling tile + insulation. The construction is a standard acoustic ceiling tile of known resistance plus 12" of R30 insulation.
Here's the question:
Is the insulation value independent of thickness? In other words, whether I have 2" or 12"...
On a self-contained liquid chiller system, I am specifying a combination filter/drier in the refrigerant circuit. With this in place, do I need to monitor the # of purge cycles in the control system as a secondary check, or is the purge method not used in the presence of a filter/drier?
TIA,
Brad
I need to estimate the condenser water flow through a pair of TRANE Centravac water chillers (one 750-ton unit & one 1150-ton unit). I have data for % compressor load on both units and incoming/exiting cooling water temperatures, but no flow data. Can the flows across both chiller condensers...
