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About the weather source I mentioned ... it can be found through the following link http://www.hnd.usace.army.mil/techinfo/UFC/UFC%203-400-02.pdf. This source quotes the same design values as ASHRAE, but includes much more information including median of extreme values of 36F winter and 99F...

In the top menu bar, under the choice for "Reports", the last two choices for "Print/View Design Data" and "Print/View Simulation Data" give you options to review loads hour-by-hour. I typically do not review this detailed data. I print system and zone reports under "Print/View Design Data"...

Others will follow, but I'll start with two things. Yes ... if you are designing air and refrigeration systems that can respond to diversity - envelope cooling in this case - then you should be using software that calculates the combined (block) load of all such spaces for each hour of the...

I would emphasize that compound fittings are among the most abused and costly of all. Duct fitting loss cefficients in ASHRAE, for example, are based upon 6 hydraulic diameters of straight duct upstream of the fitting. With one exception, there is no data upon which to base calculations of...

How about considering accuracy, installation and maintenance requirements and service conditions (beyond those noted), and then deciding upon a technology, before considering brands?

Consider a small packaged DX cooling system with supply air ducted to, and thus pressuring, each enclosure. Install a stub duct or conduit, equipped with a blast gate damper, on one knock-out in each enclosure to relieve only the amount of air required for cooling. You could waste this air, or...

The answer you seek is not so easily determined. There could be vapor transfer through the envelope of the room, due to differential vapor pressure and perhaps infiltration as well. Considering that you're posing this question after construction, it's possible (probable) that this envelope...

A reference book called "Industrial Ventilation" published by an Industrial Hygienist organization is the best source of which I'm aware, but my brand new copy is at work and I'm not. If your specific equipment is not listed, I'm certain you'll find something similar or learn the concepts and...

After participating in this forum for a few months, I have the following concerns: I have noticed more than a few posts by authors who lack common sense, and/or the ability or desire to take 60 seconds and reflect upon what they are asking before doing so. I have noticed posts by authors who...

I think we can all agree that there's generally no problem with the chilled water application. As for medium temperature heating water application, I don't believe the risk is worth the reward. I am personally aware of a Victaulic heating/cooling changeover system in a building that issued...

cme ... talking to me? I would typically use a plenum type fan as well for any air handling unit that included a discharge sound attenuator, final filter bank, humidifier or anything else that prohibited a direct duct connection to fan discharge. In the State of Washington, hospital...

Thank you, I'll probably stand corrected on that item.

Perhaps I too suffer from friartuck's malady, but I recall that older chiller control packages utilized return-side control because this temperature is much more stable than the supply-side. Nowadays, since modulation capability is more refined and control algorithms are more sophisticated...

Hint ... If you do become a project engineer and/or manager, you will then be expected to find and fix mistakes made by all who follow, so you're on the correct path either way.

mechanicaldup ... I've got to meet you someday. Talk about thinking out of the box! Limiting to one opinion for each question. Residential (single or multi) would be one of the very few upon which one should rely upon natural ventilation, but I would not generally endorse that either. I have...

Sorry about that 5 versus 12. Slap me silly for not checking the facts.

Personally, I will never again use a blow-thru coil upstream of final filters if the coil leaving air condition is close to saturation. While I can't state the cause with certainty, seeing green growth on those filters for the first (and last) time was enough for me. Kudos to the description...

Follow this link for a good description of this and similar situations: http://www.hpac.com/member/archive/pdf/2001/1001/brusha.pdf

Speaking for HVAC68, who provided a very good response, he/she meant suction and discharge piping connected directly to each pump. Stay closer to 4 on the suction side if you can. In addition, for piping that passes near to acoustically-sensitive areas, I would not exceed 7 FPS.

The previous response definitely deserves a star for content, accuracy, completeness and clarity, ... Well done!!!