My furnace is just about shot.
It’s a 70s-era oil furnace that came with the house. It smells funny, it sucks oil down like a breast-fed three-year-old, and it’s burning a serious hole in my pocket.
Since I’ve got to do something about it, I figured I’d go one step better than a simple upgrade, and put in a heat pump. Heat pumps are one of the coolest things invented in the last few centuries. (My own personal standard of coolness is the bicycle, which I consider to be the closest man has come so far to a perfect machine, with the exception of the friction brakes. All braking should be energy recapture.)
When I realized that a heat pump is effectively 200-300% efficient (compared to production of heat), I started to wonder if it could be made even more environmentally friendly by doing away with the electrical motor entirely. A little research uncovered gas-engine-powered heat pumps, but I wanted to go even farther – bicycle power.
The most popular consumer-grade bicycle generator outputs around 200 watts of electricity. If I assume that the generator efficiency is around 60% (based on data on wikipedia), and we use direct-drive of the compressor, then effective power output of the cyclist is about 330 watts.
If I was REALLY hard-core, I can imagine bicycling 2 hours, every day, for a total power generation of:
330 watts * 2 hours * 365 days = 240 kWh per year.
A two-ton heat pump from Goodman (the SSZ16, for those of you following along from home) draws 1.7 kW at 47 degrees F (the typical measurement point). If, theoretically, a one-ton unit drew only half that (it doesn’t), and we took some advantage (not much) from avoiding the electric motor and using direct drive from the bicycle, we *might* be able, with two cyclists, to run a heat pump in real time.
Wow. For a near-perfect machine, that’s a lot of wasted power.
In an upcoming post, I’ll be looking into ways we can establish a mental framework for evaluating our energy usage, and other aspects of our “inconvenience“.
#1 by Nathan on 28May08 - 3:19 pm
Hi, i’ve recently been thinking about a similar idea.
I’ve done some research and i turns out that only a top athelete cycling at full pelt can produce 200watts an hour. Obviously this stint can only be held for a short period of time. It is more realistically going to be 75watts over a 2 hour period.
My idea was to run several of these bike powered generators in parallel so you would be able to multiply your output by the number of generators you have.
#2 by inflatable dildo on 06Jun09 - 5:11 am
Wow! This innovation is very promising, can't wait for these to be massively distributed in every nation so that more people could opt for its environment friendly technology. We could go a long way with such devices, if only more people would opt for its beneficial technology.
#3 by Jonathan McCarver on 19Mar10 - 12:59 pm
What about a sterling engine mounted half indoor and half outdoor with fans on it (powered by the bike drive) A full on heat pump for a home is going to use a large part of its energy to move it’s cooling substance through long tubes but this could be enough to heat or cool a single room noticeably.