Specifications 1120 NE 28"'Ave#212
Portland,OR 97232
(503)706-7380
E C E C ed@edcrabaugh.com
EDWARD CRASAUGH
ENGINEERING CONSULTING,P.C.
DATE: 4/16/2015
Project Name: Rooftop HVAC unit
Project Address: 7409 SW TECH CENTER DRIVE,STE 125
STRUCTURAL CALCULATIONS FOR ANCHORAGE OF HVAC UNIT
building code: OSSC2014,ASCE 7-10
occupancy B
occupancy cat II
building ht. 15 ft.
wind speed: 95 mph(3-sec gust)
exposure: C (conservative)
Iw 1.0
���ED PRo
seismic des.cat D , ��GINE-, c>
site class D
SDS 0.76 ! 648•
Ip 1.0 , -
4
snow load pg 25 psf �� ✓'/ 27 1ciQ' JC7
ice load "9, Q W ,'
UNIT MFR. Bryant EXPIRES: , 1,S!
UNIT MODEL 580J-05A j f
length 74.4 in.
width 46.8 in.
height 33.4 in.
unit weight 537 lbs.
summary: A total of(1)HVAC units as noted are to be mounted upon the existing curb,currently
anchored to the existing wood-framed roof. The new unit is to be anchored per details
shown on S1.0 to resist seismic and wind shear and overturning forces as calculated on
the following sheets. No new openings in the existing roof are required.
limitations: ECEC has been retained solely for the purpose of determining the required anchorage of HVAC units due to
gravity and lateral loads. Calculations and details are based on manufacturer's information and other
information provided by the client. ECEC is not responsible for and shall not be held liable for this information or
aspects of the installation not specifically adddressed herein,including mechanical performance,waterproofing,
roof and wall penetrations not specifically addressed,electrical,zoning,servicablity,or Portland City Charter
codes,etc.
DIMENSIONS:
unit height Hu = 33.4 in G F
unit c.g. ht. Hz = 17.25 in > ""' "—"
unit width L1 = 46.8 in I .t
unit length L2 = 74.4 in �`
z
curb sleeper ht. He = 14 in
adaptor height Ha = 3 in
WEIGHTS:
i-
1 l:
unit weight Wu = 537
adaptor weight Wa = 60
curb/sleeper wt. We = 100
total weight W = 637
SEISMIC: asce7-10 sect 30.3 i
2.5 ha,, ry i
ap = ar
Rp = 6
`tr„
p = 1 V/
h = 15 ft. Y -.'-
z = 15 ft.
eq.13.3-1 Fp = 242 lbs
not to exceed Fp(max) = 775 lbs I.; l
greater than Fp(min.) = 145 lbs 1
V1 = 121 lbs per side
V2 = 121 lbs per side
overturning M = 8291 !bin
resisting M1 = 14905.8 Ibin
resisting M2 = 23696.4 Ibin
req'd anchorage Ti = 0 lbs Cs������� R�FS���C�
req'd anchorage T2 = 0 lbs „� 21
IQ
e =648*r yr
► ar
..' Ams„
WIND: asce7-10 sect 30.5.2(simplified,low-rise bldgs) `
zone = 1 fig.30.5-1 Wit r
net area 1 = 10.86 ft2 Q,tt -'6., 2 �qq9 �C9
net area 2 = 17.26 ft2 ''$?4 CRPa�
k1 = 0 W.
k2 1 'EXPIRES:1 3,1/151
k3 = 1
kzt = 1
exp.factor = 1.35 fig.30.5-1
pnet30 = 21.2 fig.30.5-1
eq.30.5-1 pnet = 28.6 psf
Fw1 = 494 lbs V1 = 247 lbs per side
Fw2 = 311 lbs ' V2 = 155 lbs per side
overturning M1 = 16916 Ibin
overturning M2 = 10640 'bin
2/3 resisting M1 = 9927 lbft T1 = 149 lbs
2/3 resisting M2 = 15782 lbft T2 = 0 lbs
2
PRO,r4,
UNIT-TO-ADAPTOR: T �OiNFF t.9
no.of fasteners along ea long side = 3 ea 648•
•
no.of fasteners along ea short side = 2 ea ,- r
—. iR •i' �
governing shear in long direction(horiz) V1 = 247 lbs 4 vW 2, lqq'6 Cj
governing shear in short direction(horiz) V2 = 155 lbs r°
governing shear for overturning shortways(vert) T1 = 149 lbs !EXPIRES: 3,1 151
governing shear for overturning longways(vert) T2 = 0 lbs
governing horiz shear per fastener v = 123 lbs
governing vert shear per fastener t = 75 lbs 1/4"X 3"SIMP SDS
governing combined shear(horiz+vert) 44 bs 18 ga STEEL
Vallow=600 lbs>75 lbs OK
ADAPTOR-TO-CURB:
no.of fasteners along ea long side = 3 ea
no.of fasteners along ea short side = 2 ea
governing shear in long direction(horiz) V1 = 247 lbs
governing shear in short direction(horiz) V2 = 155 lbs
governing shear for overturning shortways(vert) T1 = 149 lbs
governing shear for overturning longways(vert) T2 = 0 lbs
governing horiz shear per fastener v = 123 lbs
governing vert shear per fastener t = 75 lbs
1/4"X 3"SIMP SDS
governing combined shear(horiz+vert) 44 bs 18 ga STEEL
CURB-TO-ROOF: (EXISTING) Vallow=600 lbs>75 lbs OK
no.of fasteners along ea long side = 4 ea
no.of fasteners along ea short side = 4 ea
governing shear in long direction(horiz) V1 = 247 lbs
governing shear in short direction(horiz) V2 = 155 lbs
governing shear for overturning shortways(vert) T1 = 149 lbs
governing shear for overturning longways(vert) T2 = 0 lbs
governing horiz shear per fastener v = 62 lbs
governing vert shear per fastener t = 37 lbs
governing combined shear(horiz+vert) 72 bs (existing connections) OK
note:analysis is conservative,using total
overall height and weights for calculations,
even though fastener forces are less at
unit-to-adaptor and adaptor-to-curb interfaces.