This document analyzes the heating needs and costs for an apartment unit. It details the unit's dimensions, wall insulation levels, and sources of heat loss. It estimates that running the electric furnace for 15.5 hours a day would cost $343 per month. Reducing air infiltration and adding window insulation films could save 10% on heating costs annually for only $50 in materials. Replacing the electric furnace with gas is also proposed to reduce costs.

1. 345 Team Project
Ben Ness & Andrew Barbina
9 March 2012

2. 258 Chittenden Avenue

3. Apartment Breakdown
• Volume: 725 SF ; 7488 CF (3 Bed/2 Bath/ Living Room/
Kitchen)
• 3 external walls/4 windows (South, West, North)
• Thermal Resistance of walls:
Description
Winter
Outside Air
0.170
3.5" Face Brick
0.385
5/8" OSB
0.770
3.5" Blown Insulation
10.955
Inside Air Cavity
0.680
5/8" Gypsum Wall Board
0.560
R-Value
13.520
U-Value
0.074

4. Heat Loss
• Conduction: 7758 BTU/Hr (Lost through the walls and
windows)
• Air Infiltration: 1538 BTU/Hr (Medium Design build: ACH = .8)
• Internal Heat Gain: 1950 BTU/Hr (3 Occupants/Appliances)
• Breakdown:

5. Furnace Output
• Furnace: Electric/24000 BTU/Hr
• Runs for 15.5 Hrs/Day to keep steady 70 Degrees. Lasting one
month, this would equate to 465 hrs thus costing: $343.46
• If furnace runs 6 Hrs/Day for one month, this equates to $130.50
and roughly $500 for the Winter season.

6. Saving 10%
• To save 10% on our annual heating cost we have proposed 3
ideas:
1. Add better insulation/weather strip, lowering ACH to .4
(Cost=$10)
2. Add clear insulation window film to all windows, reducing
heat loss through windows. (Cost=$40)
3. Replace the 24000 BTU/Hr Electric Heater with a natural gas
unit.