a.h.u / fan room (p1 of 2) m1 - · pdf fileare32ol design 2 museum / classroom project...

Assuming that the Lobbyis mostly glass, and exposedon 3 sides, we will DOUBLE theair requirement in the Lobby...

TOTAL Bldg. Cooling Load:

60 TONSQuick check:Overall Area / Tons = ?20,000 / 60 = 333.3

STEP 1 Determine air flow req'd for each space, for total size of fan unit(s) in tons.

Equation: Area (program) / (sf/ton) = tons req'd for space

Classroom

Museum

Office

Lobby

(Note: not including Freight for now)

8100sf

8100

1100

2700

350sf/ton

450

400

350

/ 23.2 tons

18

2.75

7.7

= Classroom

Museum

Office

Lobby

8100sf

8100

1100

2700

350sf/ton

450

400

350

/ 23.2 tons

18

2.75

15.4

=

This could beadequate for a Lobby that is lessthan 50% glass

59.35 tons

ARE32OL Design 2Museum / Classroom ProjectH.V.A.C. Preliminary Design

M1

Discuss: - Methods of approximating / rough-sizing. Final design process much more involved.- What is a "ton" in HVAC.- Where do these numbers come from (sf/ton by use).- 10 cfm/person outside air included in numbers.

A.H.U / Fan Room (p1 of 2)(approx. sizing using rules of thumb)


M2

STEP 2Size the fan unit by approximating the size of the coil.

o T, use 400 cfm/ton (rule of thumb) for air capacity:A. For 20Calculate: 60 tons x 400 cfm/ton = 24,000 cfm

B. Use (rule of thumb) 500 ft./min. for air speed at coil:Calculate: 24,000 cfm / 500 ft/min. = 48 sf

SIZE OF COIL = Hdim x Wdim of A.H.U. = 48 SFLENGTH OF A.H.U. = ~ 2 x COIL SIZE

1 unit: 48 sf = 6.9' .... use 1 unit with 7' x 7' coil x 14'L

2 units: (2) at 24 sf = 4.9' .... use 2 units with 5' x 5' coil ea. x 10'L

3 units: (3) at 16 sf = 4' .... use 3 units with 4' x 4' coil ea. x 8'L

Discuss: - Delta T for Austin: 75F to 55F- Speed at air coil. - Machine access / maintenance.STEP 3

Size the coil area and initial supply duct:

A. Max. velocity for forced air = 1,000 ft/min.

From Step 2: 24,000 cfm / 1000 ft/min = 24sf coil area

1 unit option: 24sf = 4.9' .... use 5' x 5' duct (big!)

2 unit option: 12sf ea. = 3.46' .... use 3.5' x 3.5' duct ea.

3 unit option: 8sf ea. = 2.83 .... use 3' x 3' duct ea.

NOTE: Main Duct dimension can vary up to 2:1 ratio in section.

A.H.U / Fan Room (p2 of 2)(approx. sizing using rules of thumb)

2 x coil width

coil

wid

th~

4' coilcoil

Fan Room - Preliminary Design Plan Size

A.H.U.

min

.

min.min.

Single-unit design: Determine heat req'd for each space, for total heat in btu's.

Equation: Area (program) / (btu/sf) = heat req'd for space5

TOTAL HEAT:543,200 BTU

Classroom

Museum

Office

Lobby

8100sf

8100

1100

2700

28 btu/sf

24

25

35

x 226,800 btu

194,400

27,500

94,500

=


M3Boiler / Boiler Room (p1 of 2)(approx. sizing using rules of thumb)

?

Example:HydroTherm ID-85A Boiler500 mbh1'-6"W3'-6"L2'-6"H

divide by 1,000 = ~ 543 mbh unit needed.

Discuss: - BTU values for spaces by use (typ. range 24 - 30).- Units (sizing boiler): 1 mbh = 1000btu- If > 400,00 btu = "boiler" = required 1-hour rated enclosure, and periodic inspections.- If < 200,000 btu = "hot water heater"

Lochinvar 750 btu/hr unit:(Revit module for class)2'-0"W, 2'-4"L, 4'-4"H

Boiler Room - Preliminary Design Plan Size

Boiler

4'-0

" Pumps

for shallow, wide unit:

4'-0"

min.

4'-0"

min.

4'-0"

min.

min

.

Boiler Room - Preliminary Design Plan Size

Boiler 4'-0

" min

.

Pumps

for deep unit:

4'-0"

min.

4'-0"

min.

4'-0"

min.

Multiple-unit design: Total btu reqd. = 543,0003 units under 199btu has advantages.

Lochinvar mfg.

1 unit option: 1 at 500 btu, or

2 unit option: 2 at 300 btu ea., or

3 units option: 3 at 165 btu ea. (199 btu and under = hot water heater status)


M4Boiler / Boiler Room (p2 of 2)(approx. sizing using rules of thumb)

Water Heater Room - Preliminary Design Plan Size

3 water heaters

+ 2 pumps in adjacent Chiller Room

4'-0

" min

.

2'-0" Clear, typ.

Manuf: Lochinvar4'-4"H, 2'-4"L, 2'W

STEP 1Determine efficiency / life-span of unit:

Least efficient 10 - 12 year life DX system $3200/ton

25 year life air-cooled system $4800/ton

Most efficient 35 year life water-cooled system $6800/ton

(Source: S.Allen, rules of thumb based on project histories)


M5Chiller / Chiller Room(approx. sizing using rules of thumb)

Typically, building will have an air-cooled system if below 300 tons. Water is better (more efficient, longer life-span), typical on big commercial systemsover 300 tons.

STEP 2Choose unit.

60 ton req'd, min. size water unit is 100 ton (oversized, but fine)

York manufacturer, 100 ton unit:138" L (11'-6)44" W (3'-8)73" H

Discuss: - Difference between 3 systems: how they work.

York chiller, 118 tons

Chiller Room Plan - Preliminary Design Size

Chiller

4'-0

"4'

-0"

4'-0"

Plan for Tube replacement

5'-0

"

PUMPS:(2) HW(2) CW(2) condensor

Bell & Gosett1'-5"W, 4'-7"L, 1'-9"H Each

Chiller: McQuay Int.6'-2"W, 11'-8"L, 8'H


M6Cooling Tower + Enclosure(approx. sizing using rules of thumb)

Choose unit based on # tons required.

For our project, 60 ton req'd, min. size unit is 100 ton.This oversized, but fine as most units run best at about 75% capacity).

Manuf: Marley, 100 ton unit:12' L4' D10' H

Discuss: 2 How cooling towers work, types of systems, vibration and weight.

Note:Revit files and product pdf:http://seek.autodesk.com/product/latest/agg/spxcoolingtechnologies/SPX-Cooling-Technologies/SPX0001

Cooling Tower Enclosure - Preliminary Design PlanNote: THIS UNIT IS OUTSIDE (ROOF OR GROUND LEVEL)

CoolingTower

8'-0"

Typ. clearanceall around +must be opento sky.

Min. clear around cooling tower: 6' for small units.More clearance for larger units.

Cooling Tower: Morley12'-10"L, 10'-7"W, 10'-2"H


M7Electrical and Other Service Rooms(approx. sizing using rules of thumb)

10'-0"

10'-0

"

ELECTRICALTRANSFORMER:3'W X 3'L X 5'H

OUTSIDEDOOR

Main Electrical Room

ELEC. PANELS, SECURITY, TEL, A.V.

CITY ELECT SERVICE: 12,000 VOLTSSTEP DOWN 1ST OUTSIDE, THEN AGAIN INSIDE MAIN ELECT. RM.

MIN

.

MIN.

10'-0"

10'-0

" ELECTRICALTRANSFORMER:6'W X 6'L X 6'H

OUSTIDE PAD-MOUNTEDELEC. TRANSFORMER

3'x3' PAD(METER)

CONC. PAD

10'-0"

10'-0

"

OUTSIDEDOOR

Water Service +Fire Protection Room

MIN.

MIN

.

4'-0"

SecondaryElec. Room

1'-0"

PA

NE

LS

5'-0

" MIN

.

I.T. Room:Many buildings will have one I.T. Room per floor (8'x10')with it's own DX cooling system (for internet servers).

8'-0"8'

-0"

Hydraulic Elev.Machine Room

Pum

p(s)

MIN

.MIN.

For Hydraulic elevators (70' max lift):Locate machine room near bottom landing.(hydraulic fluid pumps and panels)

For Electric elevators:Locate machine room at roof above top of cab.(electric motorized hoist and panels)

MIN.

a.h.u / fan room (p1 of 2) m1 - · pdf fileare32ol design 2 museum / classroom project...

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