View Single Post
Old 07-20-2009, 09:45 AM   #4 (permalink)
Daniel_
Evil Priest: The Devil Made Me Do It!
 
Daniel_'s Avatar
 
Location: Southern England
Quote:
Originally Posted by Hektore View Post
If the cold is a problem at night, and if peeing at night means crawling out of your sleeping bag and exposing yourself to even colder air outside the tent to get it done, then it totally wouldn't be worth it to me. Especially when you consider that you're going to have to 'reheat' your bag by the time you return.

Wear and extra shirt/sweats.

My inclination is no, it doesn't make any difference for the reason you stated. The liquid has already been heated, and if anything holding it will work better to keep you warm because the added heat reservoir in your bladder will be more total volume to cool, before you die of hypothermia.

What may help, if you're not already dehydrated is abstaining from water/cold foods which would cool your core when you eat/drink them.

As for the house, in a house you heat the air, which is also what your thermostat measures. So, in theory a fuller house has less air to heat, as for heating the stuff in the house, the more stuff the more it takes to heat it. I don't know that this is answerable for certain without considering what the house is filled with.
If you fill the house with things that have a higher heat capacity than air (as most things do) it will take longer to warm up - this leads some people to conclude that it must take more energy to keep your house to temperature.

The problem is that the other side of the equation is that when your heating shuts off, those items release their heat more slowly than air would have, and therefore delay the heating system from re-starting (thus saving you energy).

On balance, what this does is slow down the cycles of your heating system.

Seeing as each time your heating system cycles (from fully cold to fully hot to fully cold again) there are fixed losses, regardless of how long it's on for, anything that reduces the number of cycles it goes through saves you energy.

Therefore in the long run, thermodynamics demonstrates that a filled house takes less energy to heat than an empty one.

Status: BUSTED

As for the urine argument, it is true that your body uses less energy to keep X kg warm than it does to keep X + Y kg warm.

The problem is, that if you pee out Y kg of urine that is warmer than its surroundings, you loose all of the heat you invested in warming up that pee to start with.

Even if you pee into a bottle and keep that inside your clothes to retain the heat it won't help, as you are moving a warm mass of pee from your core (where it is well insulated) to your outer layers (where it will bleed heat).

All in all, whatever you do it's about the same, but as with the heating system argument, the fewer times you cycle hot-cold-hot (i.e. open your clothes and loose heat while you wee) the less you suffer, so the best option is to allow your bladder to fill as full as you can manage, and then pee as rarely as you can.

Status: BUSTED
__________________
╔═════════════════════════════════════════╗
Overhead, the Albatross hangs motionless upon the air,
And deep beneath the rolling waves,
In labyrinths of Coral Caves,
The Echo of a distant time
Comes willowing across the sand;
And everthing is Green and Submarine

╚═════════════════════════════════════════╝
Daniel_ is offline  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360