Hi to all,
I have a question regarding to laboratory biosafety cabinets. I know that fume hoods can be CAV (constant air flow) and VAV (variable air flow), and on internet have a lots of schematic how to control the air for laboratory room with few fume hoods , supply air , return air..
But...
Hi,
but take a look this scenario:
When we have ice on exhaust coil , and three way valve close loop on supply AHU unit , in this part of pipe water and glycol mix stay immovable waiting three way valve..but air in supply coil still cool with very cold air because supply ahu still working and...
Hi,
You can meassure in the room, or you can take a some probe plate and with tubing supply pressure to sensor... I think that is possible...but can someone on forum to confirm...
http://www.cmr-controls.com/uk/acatalog/airprobes-1.html
But if I correctly understand you will measure a...
Hi againg,
I notice on lots of diagram that position of pumps is different:
1.In the ASHRAE diagram, it was to keep constant flow through the exhaust coil and bypass the AHU coil.
2.Coil on the AHU intake have constant flow to prevent glycol gelling.
What is the ASHRAE reasoning on putting...
Thanks for answer,
and yes bottom diagram have only pump, without control valve ( look like control valve but it isnt), just pump and how in this case we preventing freezing coil on exhaust air coil.
Can I :
1.underdimension AHU Coil on Exhaust Air and on that way preventing that temparature...
Hi to all,
I was wonder could anyone explain how works run around coil, I read a lot of about this and I notice that in some system loop we have a three way valve , and some work with two way valve or just with pump frequency regulated. If I correctly understand it well, we use a three way...
Thanks for quick answer, and one more to clarify:
1. when compressor go to off and pressure and temparatures in condenser start to equal with temparatures and pressures in evaporator, liquid when pass through capilary tube will be vapur or will be liquid? and when it comes in evaporator will be...
Hi,
I have one question about „how to work domestic fridge“. I know that compressors in domestic fridge work in cycle, but what happen when compressors off.
The pressures and temparatures in condenser and evaporator after some time are equal and liquid from condenser goes throught capilary...
Can anyone explain how it works mechanical CAV (Manual) like http://www.trox.es/---kvs-controlador-de-caudal-de-aire-/type-rn-a62db21c628cdb93.pdf
I know that have some aerodinamics force, but is it possible explain via formulas and sketch, How this device maintaining constant air flow, and how...
