TWO WALLSJ. Jennings L. Jet te R. Watson A . Wise

The BEB suffers from an extreme duality. At the very heart its construction in no way assists the needs of heating and cooling. In the winter, poor insulation and drafty windows do little to abate the harsh New England cold. Each floor, in ascending order, has poorer and poorer insulation and thus creates a series of microclimates, each one more similar to exterior temperature than the one below.

In the summer, the same issue arises. The humid heat is only trapped by the brick, and no amount of windows can create a draft capable of diverting the hot air. The BEB becomes an oven, with no cooling system capable of bringing comfort to the smaller cadres of students in the summer. The higher you are, the closer you truly feel to the sun. We provide a two part solution to address both extreme heat and frigid cold.

STATE OF THE BEB

TROMBE WALL

BEB Temp Balance Point Tbp = Thermostat setting - (Qi/UA) Thermostat Setting 65º F Qi 140967.00 btu’s/hr Q equipment 80806.00 btu’s/hr Q people 60161 btu’s/hr UA 26,470 btu’s/(hr)(deg diff ) Tbp 59.67º F

Background Information Annual Heating DD 5909 DD Annual Cooling DD 714 DD Winter OD Design Temp 9º F Winter Thermostat Setting 65º F Summer OD Design Temp 86º F Summer Therm setting 74º F Vertical solar radiation 750 HV 141000 btu’s/gal HV efficiency factor, k 0.6 Recommended Conservation Factor, CF 1.8 Fuel Cost 2.76 $/gal

Heating Load Calculations Total Heat Load Coefficient(TLC) = 24hr * Sum of UA = 635280 btu’s/day

Design Temp Difference (Delta T) = Thermostat setting - Winter OD design temp = 56º F

Design Heating Load (Qh) = UA * Design Temp Difference = 1482320 btu’s/hr

Heating Energy Estimate Annual Heating Energy Required = TLC * DD heating = 3753869520 btu’s/yr

Heating Energy Consumed (Eh) = Q heating/k = 6256449200 btu’s/yr

Annual fuel Consumed (Fheat) = Eh/HV = 44271.98 gal/yr

Annual heating cost = Fheat * F cost

=122466.67 $/yr

A trombe wall takes advantage of the large southern exposure of the BEB. By trapping the heat being lost through the exterior, along with collecting a larger amount of solar gain, students will be able to use their windows as a heat control mechanism. Automated systems can monitor and vent through the top of the wall for the overall temperature of the space, and a tubing system can transfer heat from the heat storage cavity to the fourth floor as well.

The calculations for the BEB estimate its annual heating cost to be approximately $100,000 a year. The publication Sun, Wind and Light (Brown & DeKay, 2001) estimates solar savings of trombe wall face on the BEB of up to 50% this way. HOW HOT?

Sample: Uponor

Radiant cooling system using tubing. Reduced Temperature swings. Eliminates bulky mechanical equipment. Could also support a radiant heating system (although in this case the opposing locations of heat gain and cooling gain reduce efficiencies). Comes in sheets

Radiant Rollout Mat with Wirsbo hePEX Tubing40’-160’ x 5’ Sheets. 5/8” Tubing.Poured panel with standard wood framing

Metal ʻScaleʼ Panel System

Glycol Tubing System

Insulation

FramingRiver water for Heating Exchange

Panel ElevationSection with sample Piping Layout

COLD HARD DETAILS

Sizing for a full studio-Second Floor (limited wall height, largest number of students) 100 students x 250 btu’s/hr = 25000 btu’s hr 3685 btu’s/hr (fluorescent studio lighting) + 960 btu’s/hr (incandescent desk lamps, 25% usage) + 55 btu’s/hr (cfl lamps, 25% usage) = 4700 btu’s/hr 181,500 btu’s/hr (envelope heat transfer) / 2 (for the south half of the building) = 90,750/4 (one floor out of four) = 22,700 btu’s/hr Total Second Floor Studio = 52,400 btu’s/hr 52,400 btu’s/hr ÷ 1350 sf (wall area) = 38.8 btu’s/sf of cooling are needed This can potentially be generated by 60º F water cooling system, as noted and currently in use at Carnegie Mellon’s Intelligent Workplace building. Additionally cooling the water can greatly increase the cooling capacity (http://www.cmu.edu/iwess/components/radiant_systems/performance/radiant-panels.html)

Envelope Heat TransferMaterial Thickness (in) R Value U Value Surface Area Heat Flow dT = 10º FSingle Pane Glass .25 .28 3.57 3100 sf 110670 btu’s/hrLintel/Sill Granite: 8 .083/in Doug Fir: 10 1.11/in .085 1729 sf 1470 btu’s/hrGranite 24 .083/in .502 4261 sf 21390 btu’s/hrWindow Frame 2.5 1.11/in .36 614 sf 2210 btu’s/hr

Brick Avg/Floor 18.5 .18/in .3 15312 sf 45936 btu’s/hr

Lighting Heat # usage watts btu’s/hr2 studio (ftl) 108 100.00% 1080.00 3684.96 2 studio (incandescent) 25 25.00% 281.25 959.63 2 studio (cfl) 17 25.00% 15.94 54.38 2 office/classrooms (ftl) 38 25.00% 95.00 324.14 2 hall (ftl) 34 100.00% 340.00 1160.08 2 bathrooms (ftl) 6 100.00% 60.00 204.72

Temp/BTU’s of Coolingfor radiant cooling

MATH IS COOL

HOME AWAY FROM HOME

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Our initial work served to identify the poor conditions of the fourth floor. We hypothesised that terrible insulation, outdated window details, and the large body count create an environment that more closely mimics the exterior conditions. We placed Hobo environmental recording equipment in the basement, on the second floor, the fourth floor, and in the exterior shade of the BEB to track conditions for 24 hours.

Data gathered over the 24 hour period was mapped to show temperature over time initially. We then calculated the temperatures rate of change, ultimately comparing it to exterior temperature. The fourth floor proved to be significantly different from the other floors. How then do we take our two-wall strategy, which centers around floors 1 through 3, and apply it to our initial line of research on the fourth floor?

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Fans are a natural addition in conjuction with the two-wall solution. In the winter they can help to circulate the warm air rising back towards the floor. In the summer they can be set on reverse, pulling warm air up and allowing cooler air to circulate in. A 52” fan covers a 10’ radius, meaning that two fans cover the depth of studio, and 7 sets will cover the length. Therefore each floor requires approximately 14 fans to assist in proper air circulation.

FANS OF ARCHITECURE

COOL TOWER

By address the BEB’s climatic challenges with two walls, we present a dramatic architectural intervention to a historic building. The trombe wall represents an opportunity to keep “cold & starving” students preferably “hungry but warm”, while addressing the greater desire to set our home apart from the surrounding brick and mortar landscape.

The radiant cooling wall offers not only a refreshing temperature, but also a fresh face to the architectural studios, enticing those who tour our facilities in anticipation of time here and inspiring students beginning their architectural career.HOT + COLD

PROBLEM SOLVED