Bradley Godshalk: Foundation and Architectural

Abraham Ruper: Structural

Kevin Molocznik: Fluid Systems

Charles Borrello: Building Thermal Systems

Mark Vaughn: Solar Thermal Systems

Introduction

Floor plan layout

House elevation drawings

Foundation analysis

Roof Truss analysis

Hydronic subsystem analysis

Heat Transfer analysis◦ Building and Flat Plate Collector

F-Chart analysis

Assumptions:Flexure Strength of concrete is 600 psiWeight of a house without foundation walls is 20 lb/ftSoil density at site is 87.23 lb/ft^3Factor of Safety of 5

Using max flexure strength of concrete at 120 psi after using the factor of safety, you can obtain a max bending moment of 144000 lb in by the formula σ=Mmax*c/I, where c is the distance at which the moment is applied and I is the moment of inertia

Using that maximum moment in a bending diagram, you can obtain a maximum shear value of 1800 lb, which will also equal the reaction at the top of the foundation wall

After subbing in the reaction at the top of the foundation walls into the equations obtained from summing the forces in the x-direction of the free body diagram and the moment equation, you can find the force of the soil on the wall

Using this maximum force, you can sub it into the fluid mechanics formula for hydrostatic fluid on a solid body, which is F=ρ*w*(d^2)/2, where ρ is the density of the soil, w is the maximum width of the wall without failure, and d is the distance of the soil, assumed here to be 10 feet, the full foundation wall length

The maximum length of the wall without breaking made of pure concrete was found to be 1.24 feet for our 10 inch wall. It is then every 1.24 feet that rebar will be placed to handle the bending moment. For an extra factor of safety, rebar can be placed at every 1 foot.

There are two different types of foundation walls that can be used for this foundation. Masonary wall, which is cement blocks bonded together with mortar with rebar placed in the hollow core, or a poured cement wall with rebar placed inside the poured cement. Each type will require rebar at about the same interval, about 1 foot. The costs will be comparable to each other for installation, depending on the contractor. The advantage in the long run however is clearly poured concrete, as it has a much higher insulation value, which will reduce the amount of energy used for space heating. This can save a significant sum of money over the life of the home.

The allowable bearing pressure that can be placed on the soil according to the Salt Lake City building codes is 1500 lb/ft^2. By dividing the approximate weight of the house and foundation walls, 70,000 lbs, by the perimeter of the foundation, we can come up with that the footers should be about a foot wide to handle the load safely.

Waterproofing should also be looked into for the area and the site that this house is to be built on. Options include plastic sheeting on the outside of the foundation walls and tar on the outside of the foundation walls.

Gambrel Truss Common Truss

+Customer preferred style+Less area for snow to build up around -Custom design increases cost and order to delivery time-Some usable living area is lost due to vertical truss supports-truss must help rafters support living weight on lower member

+Standard design allows for option of ordering prefabricated trusses to decrease cost+Prefabricated trusses use better materials and indoor assembly assures -Roof aesthetically similar to other homes and not style customer requested

Givens/Assumptions: -1 truss every 2’ (25 total)-Southern pine 2x12’s-Southern pine: ρ=37 ft/lb3, σb max=1.56x106 lb/ft2, E=2.8x108 lb/ft2

-Factor of safety = 5-Roof pitch: 65° lower section, 40° upper section (FPC location)-Allowable normal stress=1.66x105 lb/ft2

-Allowable bending stress=3.12x105 lb/ft2

Loading ConditionsRoofing Material - 3.8 lb/ft2

Total FPC - 25 lb/ft2 (upper section only)Snow - 42.5 lb/ft2 (upper), 5 lb/ft2 (lower)Living - 20 lb/ft2

Loading in members:BC = CD = 855.7 lb in TensionAB = DE = 1310.9 lb in TensionAE = 554 lb in Compression

Normal stress in members:(allowable 166,000 lb/ft2)BC = CD = 7143 lb/ft2 (ok) AB = DE = 10943 lb/ft2 (ok)AE = 4625 lb/ft2 (ok)

Bending stress in members:(allowable 312,000 lb/ft2)BC = CD = 5,240,000 lb/ft2 (X) AB = DE = 6,460,000 lb/ft2 (X)AE *= 11,500,000 lb/ft2 (X)

Gambrel style achievable but extra supports needed will take some 2nd floor living space

*some of living weight will be supported by rafters

Layout: The hot water storage tank will be located in the basement and piping will

run up through the house through the bathrooms on each floor to the roof and FPC’s

to minimize pipe lengths and keep piping neatly tucked away.

Pipe/Fluid Selection: CPVC – Like PVC but designed for hot water applications

50/50 Water Glycol mix for fluid.

Pump Selection: 8249K52 from the McMaster-Carr catalog, or 2 smaller circulating

pumps if a smaller, quieter, more economical pump is desired over a robust one.

Hot Water Storage & Heat Exchanger: Caleffi Solar Water Heater Tank (119 gallons)

It has a built in heat exchanger and small back up heater if supply of hot water

is exhausted.

Head value for pump: With current values 32 feet

Misc:

-Considering adding insulation to piping, low cost/easy install

-Components such as valves, fittings, elbows, can all be purchased

off McMaster-Carr

-It is not feasible to try to harness geothermal benefits in SLC

CPVC Copper

+Resistant to corrosion+Smooth bore = less noise+Cheap +Easy Installation+Lightweight+Eliminates water hammer+Unaffected by corrosives in waster that copper are affected by-Supports bacteria growth

+Durable+Does not support bacteria growth+smaller pipe sizing available+joints aren't bulky-More expensive-Greater thermal loss over CPVC-Prone to be louder than CPVC when water is running at high velocities through the piping

Section Inputs Outputs Flow RateF.R. adjusted

Pipe Diameter Velocity Friction Head Loss

Pipe Length

# of Equivalent Elbows

Equivalent Length Per cell

Total Equiv Pipe Length of Elbows

Total Equiv Pipe Length of pipe + Elbows

Pipe Losses

Elevation Out-Elevation In

Other Losses

Total Losses

CulmativeHead

(-) (-) (gpm) (gpm) (inches) (ft/sec)(ft head / 100ft of pipe) (ft of pipe) (# ells) (ft of pipe/ell) (ft of pipe) (ft of pipe) (ft head) (ft head) (ft head) (ft head) (ft)

Pump A B 0.7 0.84 0.75 0.5 3 1 0 1 0 1 0.03 0 0 0.03 0.03

Control Valve B C 0.7 0.84 0.75 0.5 3 3 2 1 2 5 0.15 0 0 0.15 0.18

Riser Pipe C D 0.7 0.84 0.75 0.5 3 45 2 1 2 47 1.41 30 0 31.41 31.59

Collector Inlet Pipe D E 0.7 0.84 0.75 0.5 3 5 2 1 2 7 0.21 0 0 0.21 31.8

Flat Plate Collector E F 0.35 0.42 0.75 0.5 1.5 9 0 0.5 0 9 0.135 8 14.6 22.74 54.535Reverse Return Pipe F G 0.35 0.42 0.75 0.25 1.5 5 4 0.5 2 7 0.105 0 0 0.105 54.64

Roof Pitch Pipe G H 0.35 0.42 0.75 0.25 1.5 3 1 0.5 0.5 3.5 0.053 -8 0 -7.948 46.693

Drop Pipe H I 0.35 0.42 0.75 0.25 1.5 31 1 0.5 0.5 31.5 0.473 -30 0 -29.53 17.165

Isolation Valve I J 0.35 0.42 0.75 0.25 1.5 1 0 0.5 0 1 0.015 0 0 0.015 17.18

Heat Exchanger J K 0.35 0.42 0.75 0.25 1.5 4 20 0.5 10 14 0.21 0 15 15.21 32.39

Isolation Valve K A 0.35 0.42 0.75 0.25 1.5 1 0 0.5 0 1 0.015 0 0 0.015 32.405*flow Increased %20 for %50 glycol/water mix

Fluid- There are 127 days in SLC where temps drop below freezing. Also the record lows hit -30F. Therefore a mix of glycol and water (50%) will

be used in the piping running from the FPC to the Heat Exchanger. With this mixture we still retain some of the benefits of using water, while

gaining the benefits of glycol and not have to worry about water freezing in the pipes. *Flow must be increased %20 for a 50/50 glycol water

mixture when compared to water.

Pipe sizing- Flow rate is one major factor that governs pipe sizing. The less flow you have the smaller the piping you need. Our system has a

particularly low flow so were going to go with ¾” piping.

Pump Selection- 8249K52 from the McMaster-Carr catalog, or 2 smaller circulating

. Both options will cover the need flow rate and head. The trade offs are that the smaller pumps are quieter, more economical. But they are not as

robust and will most likely require more maintenance.

Hot Water Storage & Heat Exchanger: (NAS20123) Caleffi Solar Water Heater Tank (119 gallons)

It has a built in heat exchanger and small back up heater if supply of hot water

is exhausted. 119 gallons was chosen after comparing various average water usages in homes. Very heavy hot water usage in families of 2

adults and 2 children were in the 119 gallon area. Average hot water usage varied from 60 to 80 gallons a day.

http://www.flasolar.com/pipes.php <-----pipe selection

http://www.flasolar.com/active_dhw__heat_exchange.php <-----ditto

http://geoheat.oit.edu/toa/toa5task2.pdf <---- study on geothermal feasability of SLC

http://www.builderswebsource.com/techbriefs/cpvccopper.htm#Introduction <----plumbing selection

http://www.aceee.org/consumerguide/waterheating.htm

http://www.siliconsolar.com/solar-water-storage-tanks.html

http://www.eagle-mt.com/radiantmax/indirect_tanks.php

http://www.bamsolarpower.com/solarwaterheater.html

http://www.mcmaster.com/#cpvc-drinking-water-pipe-fittings/=43qw8i <-pipe fittings

http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html <-sizing water glycol

http://www.engineeringtoolbox.com/pvc-pipes-friction-loss-d_803.html <- friction loss of water in pvc

http://harvelsprinklerpipe.com/harvel/pdf/friction-loss-tables.pdf <- friction loss of water in cpvc

http://www.mcmaster.com/#8249k52/=455ks4 <-pump sized

http://www.sssolar.com/Caleffi_Solar_SolarCon_solar_water_heater_tank_tech_specs.pdf

http://www.pipeflowcalculations.com <- various useful calculators

Wall construction◦ Drywall (5/8’’)

◦ Interior film (still air)

◦ Foil faced insulation and air gaps 85% of wall area

◦ Studs (2’’x6’’) 16’’ OC, 15% of wall area

◦ Plywood (3/4’’)

◦ Foil faced sheath

◦ Exterior film (avg wind speed: 8.8mph)

◦ Siding

Other construction materials

◦ Windows ≤15% of wall area

◦ Doors <5% of wall area

◦ Concrete, poured or blocks

Thermal gradient: Tin=70 F Tout=10 F

I. OptionsA. Wall versus windows

1. Buy better windows (low U-value) and insulate the walls less.

2. Buy decent widows and heavily insulate the walls.

* U-value for windows must be ≤.3 in order to get energy tax credit of $1500

B. Floor versus basement1. Insulate the first floor thus excluding the basement from

the thermal envelope

2. Do not insulate the first floor, and assume the concrete form of the basement will suffice for insulation.

C. Gambrel roof versus standard roof1. This is not the option of the Building Thermal Engineer but

it does affect the heat transfer analysis.

R-values in [hr*ft^2*°F/BTU]

WALL floor ceiling

Between Studs At studs Between Studs At studs Between Studs At studs

drywall 0.56 0.56 0.56 0.56

interior film 0.68 0.68

insulation and air gap 7 0 8.24 0 21.1 0

studs 0 6.88 0 11 0 6.88

plywood 0.94 0.94 0.94 0.94

sheath 10.8 10.8

exterior film 0.17 0.17

siding 1.8 1.8

TOTAL R 21.95 21.83 9.18 11.94 21.66 7.44

TOTAL U 0.045558087 0.04580852 0.108932462 0.083752094 0.046168052 0.134409

Rwall= 21.932 Rfloor= 9.594 Rceiling= 19.527

Uwall= 0.045595652 Ufloor= 0.105155407 Uceiling= 0.059404

U-Value standard roof Areas ft^2 gambrel areas ft^2

walls 0.045595652 2175 2315

Windows 0.3 400 400

doors 0.066666667 126 126

roof 0.059404134 1296 940

floor 0.105155407 1296 1296

basement 0.5 2496 2496

Tin [°F] 70

Tout [°F] 10

Envelope includes: area U-value U*A q Q

floor 5293 0.083 440.84 5.00 26450.38

floor & gambrel 5077 0.083 419.69 4.96 25181.51

basement 6493 0.239 1552.56 14.35 93153.50

basement & gambrel 6277 0.244 1531.41 14.64 91884.63

units: ft^2 BTU/(hr*ft^2*°F) BTU/(hr°F) BTU/(hr*ft^2) BTU/hr

subject to change

*source http://www.coloradoenergy.org/procorner/stuff/r-values.htm

Best Case Scenario - House U value of 412.6 BTU/hr-F

• 42.6% of the homes energy needs will be met by the FPC array with 5 solar collectors and a life cycle savings of $8761, and life cycle cost of $3081 for equipment and $15957 for additional heating bills.

Worst Case Scenario - House U value of 496.59 BTU/hr-F

• 38.2% of the homes energy needs will be met by the FPC array with 5 solar collectors and a life cycle savings of $8976, and life cycle cost of $3081 for equipment and $19489 for additional heating bills.

The water temperature for these values was set to 125 deg F with 120 gallons used per day, and an environmental temperature of 70 deg F. Conventional heating was provided by electricity because it was the cheapest of the alternative heat sources.

The FPC units that were used for this simulation were 21.5 square feet in aperture area and an estimated cost per unit area of 37 $/ft^2, and oriented at an angle of 40deg from horizontal.

These values and costs can be changed by an increase in the homes overall insulation, as well as the addition of more collectors, however the number of collectors is limited by the area of the roof, and the roof trusses ability to support their weight. A lower estimate of hot water usage would also result in a more efficient system, as would lowering the temperature of the water. Another option would be to remove either the DHW or heating option.