If you know how to calculate the K for the 1st branch, it is the same method for other branches. When 2 branches are exactly the same (length, sizes, fittings, sprinklers, etc), then the K for the two branches are the same. Note that you need to take care of flow & pressure balancing at...
Architect is always one kind. Engineer, being another kind, should always insist on technical performance. At the end of the project, it is always the engineer's fault when thing does not work.
When comes to this kind of situation, I would propose frameless slot diffuser for the architect to...
I am afraid there is no easy way out. Structural professional engineers hold a very heavy responsibility to ensure that any structure design (with safety factor) is safe and fit for the purpose. When a contractor submits calculation for this kind of support, I always ask for checking and...
As mentioned earlier, to determine the airflow offset or differential airflow required to attain a specific room differential pressure in relation to the adjacent space, follow the formula given earlier. A room's differential pressurization value with respect to an adjacent area is totally...
at the border of pressure drop limit! Is it the dilemma that one pipe size bigger cannot be justified (don't seems is a cost issue here)? What is your design safety factor allowance? Bear in mind that the design/calculation assumptions can never be the same as as-installed condition especially...
From the given simple question, I guess you want to know the approach on how to design/select a pre-cooled coil unit that takes 100% outdoor air at 4500 cfm (one-pass system).
To start off, you need to make a couple of decisions in your system design:
1) Is the conditioned air (after the...
Some designers prefer to use a higher roughness value to allow provision for pipe corrosion after years of service. To me, engineering calculations are estimates and are done to the best of my knowledge and assumptions with published data/common industry norm.
General form of equation across the opening is
Q = C*A*sqrt(2*dP/rho)
where
C = discharge coefficient for opening, dimensionless
A = Flow opening area or leakage area, m2
dP = pressure difference across opening, Pa
Q = airflow rate, m3/s
rho = air density, kg/m3
From the above equation, you...
For ease of reference, let say outlets 1 & 2 serve Room A. Outlets 3 & 4 serve Room B.
1) Pressure Dependent VAV box:
VAV systems are dynamic. The resulting flow at any given moment through the VAV boxes is very dependent upon the system conditions at that moment. When cooling load in Room A...
For simplicity, let take a very simple VAV system with 4 outlets. 2 outlets (say outlets 1 and 2) are fitted with VAV boxes, and the other 2 outlets (say outlets 3 & 4) have nothing (just have fixed volume control damper). The moment outlet 1 and/or 2 are closed partially, the excess air will...
As far as I know, there is no published or "quoted" rule of thumb to size the chiller plant. For building projects, the engineers/designers will use their experience gained from different type and usage of buildings to apply a "diversity factor" for his design. I won't call 2 gpm/ton - 2.5...
Mechanical ventilation is perfectly ok for chiller plants in the basement, even in hot climate countries. While it is perfectly ok to air-conditioned the chiller plants, most owners will go after the energy (operational) cost. After all, business men look at the bottom line.
Depends on your pipe design velocity. 80mm pipe size would give you 1.2 m/s pipe velocity. There are some guides on pipe velocity, example in Carrier or Ashrae Handbooks.
For high pressure gas pipeline size, NFPA or IFGC has the formula. See attached. If the allowable pressure drop is smaller, then you will get a bigger pipe size. As to your 2nd question, I have no dealing with that...
I remember there exists 2 different versions of formula. One is based on upstream velocity, and the other one is based on downstream velocity. Therefore, I am always care not to just reference to V1 or V2 as it depends where D1 or D2 is. Instead I use upstream or downstream velocity based on the...
just to add, the decoupler pipe hydraulically separates the 2 loops. The rate of flow in the primary loop must always equal or exceed the rate of flow in the secondary loop. The decoupler allows excess primary water to flow back to the return side of the chillers. If the decoupler pipe is...
