additional requirements in IMC 2006 304.10
i might be missing something but i dont see anywhere in the code or the commentary that says temporary measures are acceptable. i would have a local authority sign of before assuming that.
"The controlling resistance to heat transfer is unlikely to be the piping, whether polythene or copper"
Precisely...the primary source of resistance is the ground itself.
q = mass flow (lb/hr) x specific heat (btu/lb/deg R) x delta T (R)
in order to convert from mass flow to cfm you need to multiply by density and by 60 mins/hr.
so....
q = volumetric flow (cubic feet/min) x 60 mins/hr x 0.075 lb/cubic foot x 0.24 btu/lb/R x delta T (R)
or...
q = 1.08 x CFM...
"Guidelines for Design & Construction of Health Care Facilities"
This book was developed by AIA and the US Department of Health. Can't tell you if it applies to you project or not but its what's used around here. There are tables for minimum air changes of outdoor and supply air...
q (btu/hr) = mass flow (lb/hr) x enthalpy change (btu/lb)
mass flow (lb/hr) = volume flow (cf/hr) x density (lb/cf)
60 mins = 1 hour
air density at standard conditions = 0.075 lb/cf
so...
q (btu/hr) = volume flow (cf/min) x 60 (min/hr) x 0.075 (lb/cf) x enthalpy change
or
q = 4.5 x CFM x...
radaes,
there is no standard that specifies minimum capacities for a system. the industry standard for calculating the required capacity of equipment is outlined in the ASHRAE Handbook of Fundamentals. If your town or state has adopted the International Mechanical Code then the designer is...
yes, that method will work. you just need to setup a lookup tables for saturation humidity ratio instead of using the formulas i gave you above.
you are correct, you cannot use %RH in the mixed air equation, however what yorkman is saying is that you dont need the gr/lb to lb/lb conversion...
Try this....
%RH=H*P/(4354*Psat+H*Psat)
Where:
Psat=3226*10^(k*(1-1165.67/T))
k=4.39553-3.469*(T/1000)+3.072*(T/1000)^2-0.883*(T/1000)^3
T=Dry Bulb Temp (deg R)
H=Humidity Ratio (gr/lb)
P=Atmospheric Pressure (psi)
if you wanted to i guess you could substitute k and Psat into the top equation...
the users manual is basically the standard written in non-building code language. it does provide a more indepth look at the standard and includes a lot of examples and interpretations. i personally have and use both and would recommend getting both.
anyone ever penetrate a drywall soffit at a 45 degree angle in an exposed spiral duct application? architect is looking for a detail of the penetration.
Actually this is a high school and we have been consulted to do a review of a proposed design. I myself have never done a dual duct system either. I understand how each system functions i was just wondering if there are any benefits dual duct has over single duct vav. To me it seems the dual...
