Search results for query: *

I can't download the file at work. Most of the time, you won't need sound attenuators especially if your ahu is on a different floor than the conditioned space. In most cases, standard acoustic lining 30 feet upstream/downstream of fans works fine. To start analysis you need to get sound...

With OA=10,000cfm leakage=1,000cfm EX = SA - RA - Leakage RA + OA = SA 2 equations, 3 unknowns if you want to minimize SA, set RA=0 EX = 9,000 cfm SA = 10,000 cfm Recirculating air won't save heating energy, so there is no mixing problem.

Outside air and "air change rate" are not usually the same. Minimum fresh air is calculated per ASHRAE 62.1 or code and is often a function of floor area and occupancy. Since this affects size of heating significantly, you should minimize the outside air as much as you can. Air change is...

There has been a trend toward supplying make-up air directly to the condo units instead of the old practice of supplying air via corridor. This practice of supplying thru the corridor appears to violate a basic code principle. IMC 2009 Section 601.2 Air movement in egress elements. Corridors...

If your heating is from overhead, I don't recommend exceeding 85F, due to buoyancy. ASHRAE 62 will penalize if you exceed 85F, with overhead heating. Hot water traditionally uses 180F supply temperatures with delta T of 20/30/40. With Condensing boilers, you may want to use as low of a return...

I agree with you that your baseline should model electric heat. You should argue that your design has gas preheat, and electric reheat. I wouldn't mention the building warm-up mode to the LEED reviewer, since that is not its primary heating method. You could always warm up with your electric...

If the fan is in the airstream, the heat transfer is equal to net power. So 7.5 kw fan, gives 7.5 kw heat English units: 10 bhp x 2545 = 25,450 btu/hr

There are many systems that are prohibited from having fire dampers or smoke dampers. clothes dryer exhaust, kitchen exhaust, hazardous exhaust, stair pressurization, smoke control system, etc. Generally, you would enclose these systems in a 2hr rated wrap.