GI / GR

Gravity Vent

• High efficiency gravity roof ventilators designed using the latest Computational Fluid Dynamic (CFD) and Finite Element Analysis (FEA) software packages
• Bases are manufactured with a rounded flange around the throat that decreases pressure losses due to turbulence. (See CFD Models Below)
• Available with throats in widths from 12” to 72” and unlimited length starting at 12”.
• Units come standard with integral lifting lugs.
• Tie down points are standard to allow for additional restraints to be added in the field as required.
• Rain gutters are standard to help eliminate rain infiltration.
• Roll formed hood panels provide excellent strength characteristics as well as creating a unit that is architecturally pleasing.
• Units are designed to exceed 30 lbs./ft2 snowload rating.
• Hinged hoods are standard on GR units with less than a 73” throat length and GI units with less than a 61” throat length.

Designed with the latest in computer aided engineering software.

The new COOK GI and GR Gravity Ventilators were designed using the latest Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) software. This allowed our engineers to optimize the geometry of the throat and hood to reduce pressure losses and increase efficiency, while maintaining structural integrity. Once the design was optimized, physical prototypes verified the performance and durability of the design. The result is the most efficient Gravity Ventilator in the industry.

CFD Simulation

The figures above depict the relative turbulence of each unit and illustrate the improved airflow achieved by the new COOK design.
As can be seen in the figures, the radius throat design significantly reduces turbulence as compared to the typical square throat design.

Description: Unit shall be a hooded high efficiency roof mounted gravity ventilator.

Construction: The unit shall be of bolted and welded construction utilizing corrosion resistant fasteners. The hood shall be constructed of minimum 18 gauge aluminum, bolted to a minimum 8 gauge aluminum support structure. A radius throat must be provided for optimum performance. Lifting lugs shall be provided to help prevent damage from improper lifting. A rain gutter shall be provided to prevent rain infiltration. The base shall have continuously welded curb cap corners for maximum leak protection. Birdscreen constructed of 1/2” galvanized mesh shall be mounted in the hood. Unit shall bear an engraved aluminum nameplate and shall be shipped in ISTA Certified Transit Tested Packaging.

Product: Units shall be model GI and GR as manufactured by LOREN COOK COMPANY of Springfield, Missouri.

Intake Hood Velocity Notes

Velocity to 500 FPM: Velocity below 500 FPM provides for a level of protection against the influx of airborne mist or debris.

Velocity 500 FPM to 1000 FPM: Within this velocity range there is a possibility that fine, airborne mist will be carried into the building through the vent. Care should be taken in the location of the unit if airborne mist is a problem.

Velocity Greater Than 1000 FPM: Velocity in this range is not recommended unless special means are taken to prevent the influx of airborne matter and large droplets of moisture into the interior of the building. Velocities shown are to be used as a guide only. Final application and conditions will be a governing factor.

Dimensions (Inches)

PR

Spun Aluminum
Gravity Vent

• Spun aluminum intake/relief ventilator designed for use in both gravity and mechanical ventilation systems.
• Compact, durable and efficient.
• Bases are manufactured with a fully developed inlet to provide the most efficient and weather resistant path for both supply and exhaust applications.
• Available in 9 sizes from 8 to 48 inches.

Description: Unit shall be a spun aluminum, roof mounted gravity ventilator.

Construction: The unit shall be of bolted and welded construction utilizing corrosion resistant fasteners. The spun aluminum structural components shall be constructed of minimum 16 gauge marine alloy aluminum, bolted to a rigid aluminum support structure. The aluminum base shall have continuously welded curb cap corners for maximum leak protection. The spun aluminum baffle shall have a rolled bead for added strength. Birdscreen constructed of 1/2” mesh shall be mounted across the air opening. Unit shall bear an engraved aluminum nameplate. Nameplate shall indicate design CFM and static pressure. Unit shall be shipped in ISTA Certified Transit Tested Packaging.

Product: Unit shall be model PR as manufactured by LOREN COOK COMPANY of Springfield, Missouri.

Dimensions (Inches)

Size	A Dia.	B Dia.	C	D	G	T Sq	Roof Opening	Approx. Ship Wt.-Lbs.
8	8-5/-8	18-3/4	4/5/2008	3-1/4	2	18	13-1/2	13
12	12-1/2	27-3/4	5/1/2016	3-1/2	2	20	15-1/2	20
16	16-1/2	27-3/4	5-1/16	5-3/4	2	28	23-1/2	25
20	20-1/2	36-5/8	6-3/4	4-7/8	2	32	27-1/2	40
24	24-3/4	42-3/4	8	6-1/2	3	36	31-1/2	127
30	30-3/4	52-5/8	17-1/4	6-1/4	3	42	37-1/2	183
36	36-3/4	62-5/8	17-1/2	7-1/4	3	48	43-1/2	255
42	42-3/4	73-5/8	14	8-1/4	3	54	49-1/2	287
48	48-3/4	73-5/8	14	8-1/4	3	60	55-1/2	288

TR

Spun Aluminum Tiered
Gravity Vent

• Spun aluminum ventilator designed for use in both gravity and mechanical ventilation systems.
• Provide an increased intake area by utilizing two spun aluminum tiers and therefore, provide lower intake velocities reducing the introduction of airborne particles or moisture into the building.
• Bases are manufactured with a fully developed base venturi to provide the most efficient and weather resistant path.
• Available in 9 sizes from 8 to 48 inches.

Description: Unit shall be a tiered spun aluminum, roof mounted gravity ventilator.

Construction: The unit shall be of bolted and welded construction utilizing corrosion resistant fasteners. The spun aluminum structural components shall be constructed of minimum 16 gauge marine alloy aluminum, bolted to a rigid aluminum support structure. The aluminum base shall have continuously welded curb cap corners for maximum leak protection. The spun aluminum baffle shall have a rolled bead for added strength. Birdscreen constructed of 1/2" mesh shall be mounted across the air opening. Unit shall bear an engraved aluminum nameplate. Nameplate shall indicate design CFM and static pressure. Unit shall be shipped in ISTA Certified Transit Tested Packaging.

Product: Unit shall be model TR as manufactured by LOREN COOK COMPANY of Springfield, Missouri.

Dimensions (Inches)

Size	A Dia.	B Dia.	C	D	G	T Sq	Roof Opening	Approx. Ship Wt.-Lbs.
8	8-5/8	18-3/4	8-3/16	3-1/4	2	18	13-1/2	16
12	12-1/2	27-3/4	8-5/8	3-1/2	2	20	15-1/2	20
16	16-1/2	27-3/4	8-5/8	5-3/4	2	28	23-1/2	25
20	20-1/2	36-5/8	12-1/16	4-7/8	2	32	27-1/2	45
24	24-3/4	42-3/4	14-3/16	6-1/2	3	36	31-1/2	133
30	30-3/4	52-5/8	30-13/16	6-1/4	3	42	37-1/2	220
36	36-3/4	62-5/8	32-5/16	7-1/4	3	48	43-1/2	282
42	42-3/4	73-5/8	24-9/16	8-1/4	3	54	49-1/2	290
48	48-3/4	73-5/8	24-9/16	8-1/4	3	60	55-1/2	303

TRE

Extruded Tiered
Gravity Vent

• Tiered aluminum intake/relief ventilator designed to be one of the most flexible designs on the market.
  
• Can be tailored specifically to meet most building exhaust and intake applications.
• The tiers are constructed of high quality extruded aluminum and provide for clean lines that can meet the requirements for even the most demanding architectural applications.
  
• Available with throat dimensions from 12” x 12” to 60” x 120”

Description: Unit shall be an extruded aluminum, roof mounted gravity ventilator.

Construction - The unit shall be manufactured of 0.081 gauge extruded aluminum tiers welded to a minimum 8 gauge aluminum support structure. The aluminum hood shall be constructed of minimum 0.063 aluminum and provided with a layer of anti-condensate coating. The aluminum base shall have continuously welded curb cap corners for maximum leak protection. Birdscreen constructed of 1/2" galvanized mesh shall be mounted across the relief opening. Unit shall bear an engraved aluminum nameplate. Nameplate shall indicate design CFM and static pressure. Unit shall be shipped in ISTA Certified Transit Tested Packaging.

Product: Unit shall be model TRE as manufactured by LOREN COOK COMPANY of Springfield, Missouri.

Intake Hood Velocity Notes

Velocity to 500 FPM: Velocity below 500 FPM provides for a level of protection against the influx of airborne mist or debris.

Velocity 500 FPM to 1000 FPM: Within this velocity range there is a possibility that fine, airborne mist will be carried into the building through the vent. Care should be taken in the location of the unit if airborne mist is a problem.

Velocity Greater Than 1000 FPM: Velocity in this range is not recommended unless special means are taken to prevent the influx of airborne matter and large droplets of moisture into the interior of the building. Velocities shown are to be used as a guide only. Final application and conditions will be a governing factor.

Dimensions (Inches)

Throat Size	No. of Tiers	Hood Size	Ht.	Curb Cap Size	Throat Area			Static Pressure Drop (in W.G.)
						Ducted		0.02	0.055	0.1	0.15	0.2	0.25	0.3	0.35	0.4	0.5
						Non-Ducted		0.028	0.068	0.134	0.198	0.264	0.325	0.39	0.455	0.52	0.645
						Hood Area	Shipping Weight	CFM
12 x 12	2	23.75 x 23.75	9	17.5 x 17.5	1	2.3	47	324	513	725	888	1026	1147	1256	1357	1451	1622
12 x 14	2	23.75 x 25.75	9	17.5 x 19.5	1.2	2.4	50	365	577	817	1000	1155	1291	1414	1528	1633	1826
12 x 16	2	23.75 x 27.75	9	17.5 x 21.5	1.3	2.5	52	404	638	902	1105	1276	1427	1563	1688	1805	2018
12 x 18	2	23.75 x 29.75	9	17.5 x 23.5	1.5	2.6	54	440	696	984	1205	1391	1556	1704	1841	1968	2200
12 x 24	2	23.75 x 35.75	9	17.5 x 29.5	2	3	61	541	856	1210	1482	1711	1913	2096	2264	2420	2706
14 x 14	2	25.75 x 25.75	9	19.5 x 19.5	1.4	2.5	52	409	646	913	1119	1292	1444	1582	1709	1827	2043
14 x 16	2	25.75 x 27.75	9	19.5 x 21.5	1.6	2.6	54	449	710	1004	1229	1420	1587	1739	1878	2008	2245
14 x 18	2	25.75 x 29.75	9	19.5 x 23.5	1.8	2.7	56	487	770	1089	1334	1540	1722	1886	2038	2178	2435
14 x 24	2	25.75 x 35.75	9	19.5 x 29.5	2.3	3.1	63	592	936	1323	1621	1872	2092	2292	2476	2647	2959
14 x 30	2	25.75 x 41.75	12.5	19.5 x 35.5	2.9	5.1	69	855	1352	1912	2342	2704	3023	3312	3577	3824	4275
16 x 16	2	27.75 x 27.75	9	21.5 x 21.5	1.8	2.7	56	491	776	1098	1345	1553	1736	1901	2054	2196	2455
16 x 18	2	27.75 x 29.75	9	21.5 x 23.5	2	2.8	58	530	838	1186	1452	1677	1875	2054	2218	2372	2652
16 x 24	2	27.75 x 35.75	9	21.5 x 29.5	2.7	3.2	65	638	1008	1426	1746	2016	2254	2469	2667	2851	3188
16 x 30	3	27.75 x 41.75	12.5	21.5 x 35.5	3.3	5.3	83	932	1474	2085	2554	2949	3297	3611	3901	4170	4662
16 x 32	3	27.75 x 43.75	12.5	21.5 x 37.5	3.6	5.4	86	978	1547	2187	2679	3093	3458	3788	4092	4374	4891
18 x 18	2	29.75 x 29.75	9	23.5 x 23.5	2.3	3	61	571	902	1276	1563	1804	2017	2210	2387	2552	2853
18 x 24	2	29.75 x 35.75	9	23.5 x 29.5	3	3.3	67	680	1975	1520	1861	2149	2403	2632	2843	3039	3398
18 x 30	3	29.75 x 41.75	12.5	23.5 x 35.5	3.8	5.4	86	1004	1587	2244	2748	3174	3548	3887	4198	4488	5018
18 x 32	3	29.75 x 43.75	12.5	23.5 x 37.5	4	5.6	88	1051	1661	2350	2878	3323	3715	4070	4396	4699	5254
18 x 36	3	29.75 x 47.75	12.5	23.5 x 41.5	4.5	5.9	93	1143	1807	2555	3129	3614	4040	4426	4780	5110	5714
24 x 24	3	35.75 x 35.75	12.5	29.5 x 29.5	4	5.4	86	1033	1634	2311	2830	3268	3653	4002	4323	4621	5167
24 x 30	3	35.75 x 41.75	12.5	29.5 x 35.5	5	5.9	93	1191	1884	2664	3263	3768	4213	4615	4984	5329	5957

LSUG

Low Silhouette Upblast
Gravity Vents

• LSUG is a low silhouette, gravity relief, upblast ventilator designed for use on vertical high velocity exhaust systems.
  
• LSUG units include damper doors and a high volume rain gutter to prevent water infiltration.
• LSUG units are available in 7 sizes from 24 to 60 inches.

Description: Unit shall be a low silhouette gravity upblast ventilator

Construction: The unit shall be of bolted and welded construction utilizing corrosion resistant fasteners. The fan housing and base shall be minimum 14 gauge and the baffle shall be a minimum 18 gauge steel. Unit shall have built-in butterfly dampers of aluminum or steel construction (aluminum on sizes 24-36, steel 42-60). Curb cap corners shall be continuously welded for maximum leak protection. The wind band shall be continuously seam welded with rolled flanges on each end for strength.

Coating: All steel fan components shall be Lorenized® with an electrostatically applied, baked polyester powder coating. Each component shall be subject to a five stage environmentally friendly wash system, followed by a minimum 2 mil thick baked powder finish. Paint must exceed 1,000 hour salt spray under ASTM B117 test method.

Product - Unit shall be model LSUG as manufactured by LOREN COOK COMPANY of Springfield, Missouri.

Dimensions (Inches)

Size	A Dia	B	C	L x W	T Sq.	Material Gauge		Max. Motor Frame	Roof Opening Square*	Approx. Ship Wt.-bs. Less Motor
						Base	Hood
24	31-1/4	28	26	3	36	14	14	18	31-1/2	200
30	37-1/4	34	32	3	42	14	14	18	37-1/2	260
36	43-1/4	38	36	3	48	14	14	18	43-1/2	310
42	49-1/4	45	43	3	54	14	14	18	49-1/2	380
42	55-1/4	50	48	3	60	14	14	18	55-1/2	445
54	61-1/4	46	44	3	66	14	14	16	61-1/2	480
60	67-1/4	51	49	3	72	14	14	16	67-1/2	540

Catalog

• Gravity Catalog

Manual

• Gravity Manual
• VI/VR Manual (product model not available)

Specifications

• GI
• GR
• LSUG
• PR
• TR
• TRE
• TREH
• VI
• VR

Submittals

• VI submittal
• VR submittal
• TRE submittal
• LSUG submittal
• GR submittal
• GI submittal
• PR submittal
• TR submittal
• TREH submittal

FanDrafter files

• BD TRE,VR (dwg)
• BDI - TRE,VI (dwg)
• BDM - TRE,VR (dwg)
• BDMI - TRE,VI (dwg)
• BDI - ASP/ASPT,KSP/KSPD,PR/TR (dwg)
• BDMI - ASP/ASPT,KSP/KSPD,PR/TR (dwg)
• PR (NTS) (dwg)
• TR (NTS) (dwg)
• TRE (NTS) (dwg)
• LSUG (NTS) (dwg)