Thursday, February 19, 2009
AUTOMATED TEMP CONTROL
I am the automated temp control in our greenhouse. Sometimes I wonder if we shouldn't invest in an automated system. I have to run down to the green house at least three times in the day. That should be a literal statement. The exercise would do me good. It is an 1/8 of a mile to the garden. Downhill is not bad, but the slope coming back is at least a 45 degree one. When you get the last 200 feet it changes to almost a 60 degree slope. Quite a workout, a stair master is not needed here. Yesterday the day was overcast and never got above 35 degrees. It started with 20 degrees. The wind was gusting in a knock you over wind. The humidity was high. It felt like your flesh was being ripped from your face. The green house was kept closed all day and it never went above 55. The small inner green house (it was kept closed too), which at night the heaters keep around 55-6o, never got above 60 degrees. The heaters were off but there was no heat gain from the sun. The only thing that happened was it did loose any heat. Today is a totally different situation. The low this morning at 6 am was 5 degrees. At 8 it reached 10 degrees. This is always at least 10 degrees below what ever the Chesterfield Area temperatures are. Down at the garden it is another 5 degrees cooler. The green house when it is that cold has at least 1/8 to 1/4 of an inch of ice on the inside of the plastic. It's from the condensation of the humidity in the green house. As I mentioned in earlier post the green house floor never freezes. Two inches above the floor the air can be anywhere from 18 degrees and higher. This morning it was 24 in the main green house. The sun is shinning brightly, by 9 o'clock it was 85 degrees in the main green house and 100 in the small green house. One of the space heaters does not have a thermostat on it had continued to heat the house. With the sun shining the heat was compounded. I opened the window and door in the small green house, turned on the window fan. I turned on the main green house's inside circulatory fans and opened the back door 6 inches. I went to do the farm chores and checked the temps after I finished. The main green house stayed at 85 degrees and the small green house had dropped to 85 degrees from 100 in 7 minutes. I will check it in an hour and do some watering of the beds. I need to get them nice and moist for when we transplant the lettuce to them in 2-4 weeks. Two hours had past when I got back down to the green house. The main green house with the back door open was 85 degrees. The inner green house with the door, and window open (the window fan on) had reduced to 74 degrees. The window is located about 10 feet from the back door. The fan has a strong enough pull to pull the cool air into the smaller house. the houses should be fine until late afternoon when the sun drops behind the hill to the west. I need to go down just before this and close everything up. The temps quickly drop to with in ten degrees of the outside temps.