Heating an Ice Shack

[kevyluvu]

Hello,

Just built an 8x10 ice shack to do some winter work in the Bering Sea off the coast of Nome, AK. The Shack is well insulated with r19 walls and r30 ceiling and floor. 6mil plastic on the inside and Tyvek on the outside. One weatherproof door and one double pane window. Purchased one of the last M2200's up here. Planning on running it on low 24/7 to keep the shack and the components inside from freezing. Figure I'll put a resistor in place of the thermostat to trick the heater to think it's 72 degrees +/-. I will set it 2 degrees higher so the heater never cycles and always runs on low 24/7.

My question is this... Without further testing (which I do plan on doing) what do you think would take less electricity, running the heater on low like described above, or letting it cycle using more energy to start the burn with the igniter. For the cycle option lets just say I have the heater set @55 degrees. The heater turns on and takes 10 min to get up to 59 degrees before shutting down again to repeat the cycle in another 10 minutes. So in 24hours the heater cycles 72 times. How much juice does it use in 24 hours compared to the heater just being left on low 24 hours in low with just the fan running?

The reason I ask is because I want to figure out how many deep cell batteries I will need to hook up in parallel to provide enough power to run the heater for 24 hours. I will be visiting the shack daily to do work, and while I work over a period of 3-4 hours I will recharge the battery bank with an alternator. The fuel usage is not important. To me the less power used the better. I will be using a 1000watt pure sine wave inverter.

-Kevin

PS: Where do I find the 2pin tactile switches monitor uses under the buttons?

[HayZee518]

you'll have to do some figuring for the draw on the inverter per hour of usage. the combustion fan draw is continuous. greatest draw is start up as most motors are a direct short until they come up to speed. the fan doesn't turn on until the plenum limit switch closes, then the computer takes over for the remaining speeds. do you plan to measure the thermisters value at 55 degrees? the heater overshoots the set point by 2 degrees. go to allelectronics for the switches they are in california.

[kevyluvu]

I'm a noob when it comes to electronics. Just bought my first meter yesterday for this project. I just started repairing monitors up here and we use a 100ohm resistor which makes the old heaters think it's 72 degrees so we can hook up the manometer for fine tuning the air setting after a rebuild. The new 2200 does not let us adjust the air, but I was hoping I could still wire in a resistor (to lock the heater temp) to keep the heater running on low nonstop (only if it uses less electricity than running it normally letting it cycle). The 55 degrees was hypothetical if I was to set the heater up to run normal. If I have to run the heater by tricking it to stay on all the time on low to save electricity, (run fewer deep cells) I will be happy with whatever temperature it produces. Since the shack is less than 100 square feet it might produce 70-80 degrees and that would be fine by me. I figure if I ran it normally the temp I would prefer is around 55 degrees to keep things warm enough, but not so warm that it’s constantly cycling and eating too much fuel for the intended purpose. If I ran it non-stop the fuel issue becomes obsolete. For running normally the unknown factor is the weather. It gets negative 30 up here sometimes. I’ll do my tests when it gets to negative 5 or so. It’s been hovering around zero for the past couple weeks.

You wouldn’t happen to have the link to the tact switches handy? I found some on the site you suggested, but not sure if they are the right ones. We keep old boards around to rob the switches, but the bone yard is getting low on supplies.

[kevyluvu]

I guess the main thing I'm trying to figure out is how many deep cell 12v batteries will I need in a 24 hour period running the heater nonstop on low or letting it cycle. If I need 3 batteries to let it stay on low all day long and 10 to let it cycle then I'll let it run on low all day. I figure a good battery is a couple hundred bucks so $600 for 3 versus $2,000 for 10 is a pretty big difference. If however I saved a high % of fuel by letting it cycle normally @55 degrees and it only took a couple more batteries to let it run normally, well that would be the most cost effective solution. Planning on doing this work for 2 months.

Think you right, just gonna have to do some testing. Figure out how much fuel I use too.

-Kevin

[HayZee518]

I know the heater operate in continuous mode when the thermister is disconnected. no matter what the set point is set at, the heater keeps thinking it's 42 degrees and constantly runs.