Hello All,
I've been posting on these boards for around 9 years (where does the time go?).
With my handle I've been less anonymous than most, and through a variety of circumstances I’ve gotten to know a few people on the boards professionally.
I’d like to invite anyone that is interested to...
I'm working on a little project where the client would like to hodge together a few growth chambers (rather than purchasing them).
One of the criteria I've been given is to be able to maintain the chamber at 4 deg C (40 deg F) with air at 1 deg C (34 deg F) to prevent freezing the plants...
I have a client with a Fibre Glass manufacturing facility. (Styrene Cross-Linked Composites Manufacturing). They've been tagged by the fire inspector as being deficient in NFPA 33 and some items of the Canadian National Fire Code.
My two questions are:
NFPA 33 calls for sprinkler protection in...
This is a little obscure request, but I'm hoping someone out there can point me in the right direction.
I'm trying to design a self balanced air distribution plenum by pressurizing a piece of ductwork and cutting holes of increasing size to deliver the same volume of air to each hole as we...
We've been having problems on projects with point of use tempering valves matched with single temp infrared (or mechanically metered) faucets.
With all the LEED and conservation push we've been specifiying 0.5gpm aerators on these devices. The isse is that the amount of time that the faucet is...
Hello All,
A long while ago I read an article on the placement of differential sensor in a hydronic system. Basically it boiled down to the rule of thumb standard to locate the DP sensor ~2/3 of the way into the hydronic system (how exactly you find that point in a real system was not...
We've been using the same heat gain from computers for quite a while now in our cooling load calculations, despite the fact that computers are running more efficiently and LCD monitors are much cooler than CRT.
Does anyone have a website or resource that lists 'actual' heat gain from computer...
With LEED we're being pushed to consider reusing grey water in building (all water in the facility not coming from the toilets and urinals) for reusue in irrigation, toilet flushing, cooling tower make-up and other non-potable applications.
I haven't found a clear standard that says: do this...
My question is regarding hydronic heating and cooling systems.
Is there a standard that states when a pipe is considered 'supply' or when it is considered 'return'?
Does pressure determine tagging, or does temperature?
It's fairly easy in the space to determine supply and return, but in the...
We have a client that has expressed interest in using fabric ductwork (like DuctSox http://www.ductsox.com). The product seems fairly applicable to pool enviroments: washable, not affected by corrossion, good airflow pattern control.
Having said the above, I've never used fabric ductwork...
We have a dust collector installation (~10,000 cfm against 8" e.s.p.). The unit is ducted return back to the space, with a 5' silencer on the return.
The problem is that the system has a low frequency rumble that literally shakes the whole room, you can feel it deep in your chest.
Anyone out...
We have specified a 'Sapphire' Clean Agent fire suppression system for a server room application. The system will conform to NFPA 2001.
The building in which the server is located is sprinklered throughout (conforming to NFPA 13).
NFPA 75 seems a little ambiguous if gas systems are able to...
In a school that is sprinklered, are sprinklers in the trophy cases / display cases required?
We are working on a major renovation to an existing school. The school currently has a number of recessed and semi-recessed display cases. Due to the construction (concrete lintel above the cases) we...
ASHRAE recently* published an updated to their latest ventilation standard 62-2004.
One of the more significant changes was that they decreased the 'per person' ventilation and added a 'per area' component.
For those not familiar with the standard a typical example with a classroom would be...
Hi all,
Not necessarily looking for the answers here, but does anyone participate in a forum for Carrier's HAP software? I've got some fairly specific questions relating to modelling WSHP and GSHP.
Or if anyone considers themselves a HAP guru I'd appreciate any tips you might have for...
How much heat should I expect to be rejected from a server rack rated at 7.2 kVA?
I converted kVA to kW for my initial calculations, but is it reasonble to expect 100% of the load will be rejected as heat into the space?
I know I've read a thread comparing load programs but couldn’t find it when searching.
I’m looking to compare:
Carrier's HAP vs. Trane's Trace700
I hate to dredge up an old topic, but our office is looking to fully commit to software; what do you use for load simulation?
I use the HAP...
The plan approval engineer for the AHJ has indicated on a recent high school project that the Home Ec lab must meet the requirements of NFPA 96. The lab consists of ~10 stoves with residential range hoods. There is no deep fat frying at all.
I've always assumed that NFPA 96 was aimed more at...
Hello All,
I'm looking into the possibility of a variable primary flow chilled water system. I've heard all the warnings about minimum flow, but the client would still like to investigate. The system is a retrofit ~750tons, water-cooled chiller. We are replacing the existing chiller, cooling...
Does anyone have a general formula for estimating horsepower (bhp) requirements per cfm?
I'm just looking for a rough number for estimating the fan motor horsepower on a large number of fan coils, and I would like to avoid selecting 150 fans at this point just to determine what the approximate...
