Home Heating Calculator
Synopsis
Home heating costs are affected by improvements to the house heat
retension (e.g. in wall and ceiling insulation,
windows, stopping drafts etc) and heat generation (e.g. efficiency of
furnace, changing to geothermal heat pump, solar heating etc)
The task in this project is to write a flexible heating calculator
which allows an average homeowner to draw a dimensional sketch of his/her home,
and enter the insulation values (R-values) of the different components
using dialog boxes, one for each element (ie. one for all similar windows,
one for the walls, one for outside doors, etc). This represents the heat diffusion losses.
Once the present house is drawn the system should support for example:
- Report heat loss from a particular component type as percentage of total
- Report relative gain for a specific improvement (ie changing wall insulation from R10 to R19)
- Given information on the heating system and gas/electricity costs
calcululate absolute heating costs for particular inside/outside temperatures.
- given average annual temperature distributions calculate yearly heating
costs.
- Support answering question such as how much do I save by changing
from a 70% efficient furnace to a 90% efficient? Changing windows from
R2 to R3?
- Consider adding losses from drafts, cracks etc. Search for "stack effect" and the cossesponding equations.
Suggested steps and deliverables
- You can do this as an extension to the similar lab and lecture materisl using the matlab GUI's
- For those who took 301 this year you could write a java applet extending
your 301 project.
References
- Try "matdraw" and do "type matdraw" (This assumes you set your path
to include the extra matlab libraries in c340, see the newsgroup and lab 1)
You can base your house drawing and gui on matdraw. (ie modify and extend this program)
- The book Sustainable Energy - without the hot air by David JC MacKay has a good description about the mathematical models governing home heating and loss in
technical chapter E note that this bool uses the term "leakiness" to describe both diffusive conducytion loss and loss due to ventilation air leaks.
- See assigment 2 for insulation coefficients and heat tables for various appliances.