4 ms·

Why do we keep trying to come up with ways to heat things when a human is a 100 watt heater at rest? Just insulate the building properly and then you can use r

Why do we keep trying to come up with ways to heat things when a human is a 100 watt heater at rest? Just insulate the building properly and then you can use rooftop solar to cool it down on those days when it gets too hot - largely because the sun is shining. Moving heat is generally easier than generating it.

speedplane 8y ago
Unless you live in a styrofoam box, you're going to need heating. Also, people like windows.
- neilwilson 8y ago
  PassivHaus standard can be warmed with a 1Kw heater at -10 degrees celsius. They have windows, doors and mechanical ventilation.
  - speedplane 8y ago
    I just read about Passive House, thanks for citing it. The standard requires less 15kWh/m^2 per year. I live in the U.S. in a 1200 sq ft apartment, small for U.S. standards, and that comes to ~4.5kwH per day. To put that in perspective, an 80 Watt computer running all day uses up nearly half of that margin. A small 6000 BTU A/C (good enough for a small bedroom) uses up the entire allowance if you run it for 8 hours in your bedroom while sleeping. An electric dryer will use up the entire allowance if you do two loads of clothing. I love that people are thinking about this, and I truly hope that it becomes standard, but it's not exactly reasonable for folks to expect such a level of efficiency without paying through the nose.
benj111 8y ago
This seems like a reasonable argument for wearing a jumper. I think you're firmly into diminishing returns if you're insulating your house to be warmed purely by body heat through the depths of winter. Plus what happens if you have a child? Do you remove insulation, run the AC through winter?
- neilwilson 8y ago
  You run the AC as required. An argument against that is that the work energy counts against the operation of an AC unit, whereas it works for the operation of a heat pump. So you get a better CoP heating.

speedplane 8y ago

Unless you live in a styrofoam box, you're going to need heating. Also, people like windows.

neilwilson 8y ago
PassivHaus standard can be warmed with a 1Kw heater at -10 degrees celsius. They have windows, doors and mechanical ventilation.
- speedplane 8y ago
  I just read about Passive House, thanks for citing it. The standard requires less 15kWh/m^2 per year. I live in the U.S. in a 1200 sq ft apartment, small for U.S. standards, and that comes to ~4.5kwH per day. To put that in perspective, an 80 Watt computer running all day uses up nearly half of that margin. A small 6000 BTU A/C (good enough for a small bedroom) uses up the entire allowance if you run it for 8 hours in your bedroom while sleeping. An electric dryer will use up the entire allowance if you do two loads of clothing. I love that people are thinking about this, and I truly hope that it becomes standard, but it's not exactly reasonable for folks to expect such a level of efficiency without paying through the nose.

benj111 8y ago

This seems like a reasonable argument for wearing a jumper. I think you're firmly into diminishing returns if you're insulating your house to be warmed purely by body heat through the depths of winter. Plus what happens if you have a child? Do you remove insulation, run the AC through winter?

neilwilson 8y ago
You run the AC as required. An argument against that is that the work energy counts against the operation of an AC unit, whereas it works for the operation of a heat pump. So you get a better CoP heating.