Hi folks, I'm in the process or recommissioning a multistack heat recovery chiller Link
The chiller wasn't commissioned/set up properly and hasn't run much since it was installed.
I'm wondering if anyone could shine some light on entering vs leaving chilled water control? The chiller can be...
Hi,
Two questions:
Easy one first: Do you have a recommendation for a DHW heater sizing resource?
Second question: I am trying to determine the capacity for an existing Domestic hot water system.
I've been reviewing articles and literature to determine the actual capacity of usable hot water...
Hi folks, I am looking for some assistance with a hydronic system that serves our chiller plant. We have 3 chillers served by two dry coolers. The condenser loop is a closed loop system and uses 30% ethylene glycol.
The loop temperature is 45F in the winter and goes as high as 110F in the...
I came across this article here https://www.hpac.com/iaq-ventilation/article/20928092/controlling-outside-airflow-in-vav-systems
that describes a way of controlling outdoor air flow accurately.
TLDR: This strategy relies on maintaining a fixed differential pressure across the outdoor air...
I was reading the help file that comes with Carrier HAP and it mentions that ventilation load is calculated relative to exhaust air. Whenever I do hand calculations, I calculate the outdoor air ventilation load by taking the delta T between my outdoor air temperature and my cooling/heating coil...
Hi Folks,
I have a Supply Fan Delivering 22,500 CFM of Supply Air. A Return Fan bringing back: 20,200 CFM. And a washroom exhaust fan in the space exhausting 1000 CFM.
To Summarize:
SA: 22,500 CFM
RA: 20,200 CFM
Washroom Exhaust: 1000 CFM
What is my Outdoor Air rate?
Hi,
I am trying to understand the losses due to system effect for not having the recommended straight section of duct in an exhaust fan application. The existing fan is shown installed in the image. There are two main system effect losses at play here from what I understand.
1) Losses at the...
Hi,
I am trying to understand the losses due to system effect for not having the recommended straight section of duct in an exhaust fan application. The existing fan is shown installed in the image. There are two main system effect losses at play here from what I understand.
1) Losses at the...
http://static.schneider-electric.us/assets/consultingengineer/appguidedocs/section5_0307.pdf
In the PDF linked above on page 3. they compare two different types of radial systems, figures 5-4 and 5-5, and say that:
"A more reliable and maintainable arrangement utilizing multiple primary...
I am trying to calculate the current running costs of a a system very simillar to what can be seen here: http://upload.wikimedia.org/wikipedia/en/6/67/Dust_collector.jpg
my system utilizes a 60 hp centrifugal fan that is not modulated in anyway. However, I believe that when the dampers at a...
Hi I am attempting to do the short circuit current calculations to determine an appropriate fuse size and I was wondering if some one could give me some pointers. The calculations are for a run between a 3ph 600/347V padmounted transformer and a switch gear. We are putting in a new 3ph service...
Hi I am attempting to do the short circuit current calculations to determine an appropriate fuse size and I was wondering if some one could give me some pointers. The calculations are for a run between a 3ph 600/347V padmounted transformer and a switch gear. We are putting in a new 3ph service...
Hi guys,
I need some help here. I have the SMACNA HVAC duct construction standards book open in front of me. I am designing a 72" X 43" supply duct with a 3" in. wg static pressure and 29400 CFM. I would like to determine the appropriate sheet metal gauge to use for this application but I am...
Hey guys, I am doing some pressure loss calculations for a duct run. The duct starts at a roof top heating and cooling unit. I have the spec sheet here http://i.imgur.com/xXWhI.png and I am not quite sure which value to use for the ESP, should I use 3.0 in. wg or the 4.7 in. wg as mentioned in...
Hi Guys,
I am trying to do some calculations to figure out the decrease in heat gain through the roof due to the installation of a new water proofing membrane (Lexcan TPO 1.1mm). I have the SRI for the new membrane but I am at a loss on how to proceed from here. Any pointers would be helpful.
