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Thanks Dave. It finally makes sense.

Hi all, I'm sorry for posting, but unfortunately the search isn't working. Could someone please explain the difference between a floating ball valve and a trunnion mounted ball valve? And what is double block and bleed on a trunnion mounted ball valve? Thanks in advance.

Thanks Friar !

Thanks MintJulep, I was just about to use that equation then I thought "wait a minute". So in this case I would have to use some type of cooling ie. glycol cooling coil or something. Right? Thanks again.

Hi all, I'd appreciate it if someone could set me straight. I am working on designing an exhaust fan for a small building. I have calculated the heat gain for the room and know that the outdoor design temperature is something like 28*C while the desired inside temp is about 20*C. Using the...

Wow, you guys are great. That makes a lot of sense walkes. That is what my calculations show as well. Thanks !!

IRStuff, You are probably right. But it is always nice to know how they have made their calculations so that you can cross reference your calculations with theirs, even if mine is somewhat uneducated.

Electric heater location is inside and they will have unit mounted thermostats. A central ventilation system will be supplying the building (large room) with outdoor air. Thanks lilliput1 for replying.

Thanks MintJulep, I know what you mean about keeping your units in tact, can be a pain in the a$$, especially with switching back and forth from SI to Metric. Once I take into account the doors and windows should I be fairly close to having the right heating requirements, so I could just add...

Goodmorning All, I am trying to calculate a rough estimate of heating requirements so I can size some electric heaters. I’d appreciate it if you could tell me if I am heading in the right direction. 1. I have calculated how much heat will be lost from the building assuming that the walls...

Thanks Walkes, I appreciate your help very much. The system is for Fort Mac, a 99.6%DB of -34 deg C. Dave

I am trying to size a heater for a building in a cold environment. I am not sure what outdoor temp I should use from ASHRAEs "Heating and Wind Design Conditions". Should I use "Heating DB 99.6%" or use "Coldest Month MDB 1%" Thanks for your help

Hi Chris, Thanks for the info. So what your saying is if I know the R value of the insulation around the piping and the inside temperature then I should be able to calculate the total heat leaving the pipes using equation Qout=h*A*deltaT where h is the convection constant, A is the surface area...

I am working on a project where I have to put a new HVAC system in a building full of pipe transporting hot bitumen and steam. The building is H5.2m x L15m x W7.2m and is at a temp of 40 deg C. How should I approach this problem? I have been told that there are not many people in this...

Using basic heat transfer rules I have determined how much heat will enter a room on the "design day". I have also added the amount of heat rejected from equipment in the room to determine the cooling load on the air handling unit responsible for cooling the room to a predetermined...

Thank you very much atad !! Dave

I was recently told from some field operators that they are having trouble opening and closing ball valves. As a matter of fact they are having such a hard time closing the valves that they are bending the handle. Are welders expected to remove the bonnet and the contents of the valve before...

Thanks guys, once again you have come to my rescue. Dave

When I read, for example, 8 air changes per hour I get the impression that I must replace the room 8 times in one hour with FRESH AIR. Is it FRESH AIR? Thanks

I was told a while back from this very useful forum that you shouldn't take the tag value of a piece of equipments heat dissipation when calculating the total cooling capcatiy of an AHU. I was told to that the air handling unit would never have to handle the full 100% load, instead take 60% of...