Tertiary Piping

Killer link Sparkstation---

Thanks,,,now I'm gonna need to put another pot of coffee on

Trying to stuff 15 to 30 years experience into 1 week is one heck of a roller coaster

ride. I'll just do my best and try to digest everything you guys have been feeding me.

Hello again quest,

Here is a to go with your coffee.....

Thanks man--- looks tasty

To allow for compensation? Load/demand balancing?

Tertiary pumping has three "levels" of pumping. The first level, or primary, is constant volume pumping through the chiller's evaporator bundles. These pumps run when ever a chiller is on. Each chiller has a dedicated primary pump. The secondary pumping system is typically a variable volume scheme that is controlled with a variable speed drive based on "building" differential pressure. This is a pressure differential sensor located between the chilled water supply and return. The VFD is controlled to maintain a differential pressure setpoint. As chilled water valve(s) in various AHUs modulate to maitnain SAT setpoint, a variance in flow is required through out the building. The VFD allows the secondary pumps to respond to building load and operate in a more energy efficient manner. The secondary and primary loops are separated from each other through a "common" pipe. A tertiary system has a third level of pumping. In a building, that third level or tertiary pumping will be at the air handling units. It will be used to provide additional head to move flow through the air handler's cooling (or heating) coils. In a campus design, the tertiary pumping may be a "booster pump" located at a campus building with the primary-secondary located at a central plant that distributes water to all of the building throughout the campus through a massive system of piping located underground.

Hope this helps

"Guest"---

Thanks,,,now I have a large bump on my head after I hit the floor!!!!!

That in depth, yet simple answer really clears things up....

I checked out some sites but none were able to sum it up on one paragraph,,,,very nice

Helped a lot---thanks again for your time

Hi Quest,

Further to what other contributors have added, one important use of a tertiary system in High Rise buildings is to reduce the effects of head pressure by incorporating heat exchangers and pumps to work at a lower pressure on the lower floors. The head pressure works out at approximately 1 bar (15psi) for each 10m (30ft) of height. This could mean something like 20 -30 bar or more at ground level for a 40 story building, increasing the cost of valves and fittings to withstand and operate at these pressures. So basically you have a tertiary circuit serving floors 1 to 20 at 10-15 bar with heat exchangers interfacing the secondary circuit and the secondary circuit serving floors 21 to 40 operating at a similar pressure.

apologies if i have rambled a bit, this is my first contribution.

Thanks Paulus--

Every post has some new insight to it and yours in no exception,,, that is some valuable info

First post,,,,,well then--------------welcome to the club--------------------------