Green House Adventures

More Temperature Stats

2011-06-05T21:00:00.000-07:00

Lettuce, green onions, basil, green beans, cilantro, tomatoes, and radishes are growing nicely in pots my Juwel 1000 cold frame. It is just sitting on the pavement in front of my house. Here are the latest statistics from my thermochons.

	Outside	Inside	Difference
Maximum	79.70	73.40	14.40
Minimum	55.40	51.80	0.90
Average	63.34	58.75	4.59

Temperature in degrees Fahrenheit

At this point I've had to move the lettuce out to the greenhouse because it was getting to tall. I would still be ok, if the top of the pots was the same level as the bottom of the cold frame. I installed an automated opener since I shared the last set of numbers.

What next. I would like to build a small box that this can sit on top of so that the top of the containers will be at the bottom of the cold frame or just below it. This would also allow me to hold in more thermal mass to help stabilize the temperatures. Once that gets setup I'll consider adding a grow light and an warming light as a heat source to get things started earlier next spring. Until then I'll be enjoying my fresh tender lettuce and green onions.

Juwel 1000 Cold Frame: Temperature Testing Research Part 2

2011-04-24T10:26:00.000-07:00

After looking at the previous results (see part 1) of my temperature experiment with my Juwel 1000 I decided to add a row of bottles of water around the perimeter of the inside of the cold frame to see what effect that would have.

Click to enlarge

Here are the statistics from the data for the graph above.
Maximum temperatures: 85.1F (inside), 63.5F (outside), and 23.4F (difference)
Minimum temperatures: 37.4F (inside), 27.5F( outside), and 3.6F (difference)

Conclusion:
The thermal capacity of the water bottles was enough to keep the temperature inside of the cold frame above freezing when the weather is clear during the day and the temperature drops below freezing at night.

Greenhouse Temperature Comparison Results

2011-04-24T10:10:00.000-07:00

After experimenting with my cold frame recently (see Juwel 1000 Cold Frame: Temperature Testing Research Part 1) I decided to do a little research about the temperatures in a greenhouse. Here are the results. All three days were clear skies and calm. The maximum inside temperature was 98.6F and the maximum difference in temperature between the inside and outside was 37.8F while the minimum temperature difference was 6.3F

Click to open interactive graph

The greenhouse is a south facing lean to style with a concrete floor. Currently there is a lot of miscellaneous stuff in the greenhouse, but nothing with very much thermal mass.

Conclusion:
The design and size of the greenhouse seem to be able to absorb a lot of thermal energy but there is not enough mass to retain it over the night.

Thrifty Hydroponics

2010-05-11T22:59:00.000-07:00

After analyzing last years results of my AeroGarden and the fact that the air pump went out on it shortly after the first year. I've quickly realized that yes the herbs are fresh, fun, and good to eat but not economical. While pondering different hydroponic options that I could experiment with for this next year I stumbled upon the fact that the AeroGarden seed holders will fit perfectly inside the mouth of a Welch's^® grape juice container. A hole saw can also be used to make 2" and 3" netpots work as well.

Here is a list of materials for my next experiment.

Materials:

Welch's^® Grape Juice bottle or similar container.
Aquarium air pump.
3' feet of air hose.
Silicon
Seed holder

Net pot 1.5" or 2" with clay
Used AeroGarden^® containers w/rockwool)

Seeds
Paint (I used black spray paint)

Optional:
Aluminum foil - to prevent light from reaching the nutrient solution.

Drill a hole the size of the air hose in the top near the mouth of the container and near the bottom preferably on a flat side.

Cut a length of hose just longer than the container is tall. This piece will extend from the bottom of the container up to the top to serve as a water level indicator and a way to drain it when the water needs changed.

Variations
AeroGarden:

Purchase AeroGarden^® seed kit and you are ready to go since it comes with nutrients.

Netpot:
Use a hole saw to create a larger opening in the top of the container. I found that the easiest way to do this was to place the cap on the container and use it to help keep the hole saw centered. Be careful to go slow so that the container doesn't tear or melt. When the holesaw starts to bind put drill in reverse.

Juwel 1000 Cold Frame: Temperature Testing Research Part 1

2010-03-24T19:20:00.000-07:00

A while back I was given a Juwel 1000 and this spring I finally got around to testing it out. The current temperatures over the last couple of days have ranged from about 20F to 55F.

To start with I've placed the Juwel 1000 on my back porch. It is a wood deck type porch that is currently surrounded by snow and has ventilation through the floor. With this setup the cold frame is not sealed on the bottom. Over the last couple of days I placed one of my Thermachron sensors inside and one outside and created the temperature graph above. The maximum temperature difference was 21.6F and the minimum was 0F. The maximum temperature inside was 83.3 and the maximum outside was 63.5. Minimum inside and outside temperatures were 23 and 21.2 respectively.

I have plans to put it on top of a simple plywood box that will house some containers or hydroponic systems, some water containers as a heat sink/stabilizer, and a light bulb or a small heater hooked up to a thermostat. I'll post the info when I get it set up.

AeroGarden Update #2

2009-04-15T18:00:00.000-07:00

Wow I guess it has been a while since I've posted anything here. We'll things have still been growing. We have harvested over 400 grams of herb's from our AeroGarden. We also added some chive seeds to the chive seed holder since they didn't sprout. I think they must have gotten knocked out or something.

We ran out of the AeroGarden nutrients after we had collected about 300 grams. I think we probably would have gotten a lot more except for the fact that this has been grown in Alaska in the winter. If this would have been grown in the window during the Alaskan summer I'm sure it would be a hole different story.

I went down to the local hydroponics store and picked up some hydroponics nutrients and a ph/ec/tds/temp meter to help see if we could extend the season. The dill has gotten to tall for the planter and has fallen all over and is starting to go to seed but everything else is growing very nicely.

Since we have started adding the liquid nutrient I've noticed that the mint leaves are significantly larger. I don't know if this is due to the nutrient or the change in ph though. Since we got the meter we've been able to pay more attention to these levels.

Below are the results of what we have harvested and other interesting pieces of information.

Conclusions thus far:

With the provided tablets the savings from using an AeroGarden are questionable. By supplementing with nutrients from your local hydroponics store the economics becomes quite reasonable.
Maintenance has been very easy. The biggest problem I have is that the unit is in my classroom at school and not at my house. Because we are measuring everything that we harvest from it, I've missed a few good opportunities to enhance the flavor of my sandwiches. Also some of the herbs that have been taken home have gone bad because I didn't use them up quickly enough. If I had the AeroGarden at home I don't believe that I would have had this problem, that this is a personal problem not a problem with the AeroGarden itself.

Aero Garden Update #1

2008-12-16T17:27:00.000-08:00

The Aerogarden has been doing well so far. Here are the current totals of what we have harvested.

7.99 g Basil
0.91 g Mint
0.81 g Thyme
0.44 g Oregano
3.80 g Dill

Totaling 13.95 g

We've used over 10.21 KWH of electricity. This is measured using a KillaWatt meter purchased from NewEgg.com.

The basil really grew fast and we've actually had to prune it back three times now in order to let everything else catch up to it. At this point the basil and dill seem to be doing the best. The mint has really started to take grow now. Looking under the hood it has a pretty significant root system. The oregano is probably the slowest growing of the bunch. Maybe everything will start growing better now that it has all been pruned back a little bit.

One improvement that I would really like to make to the system is to put a little fan somewhere to help them grow stronger. I think that this would also help some of the lower vegetation to get some more light and promote stronger healthier plants.

Life is full of change.

2008-11-18T21:00:00.000-08:00

Unfortunately if you have been following the different greehouses that I have built they have been put on hold until I have a place that has room for building a new one since I left my old one at my old house. I've taken a new teaching position in Alaska and am currently renting an am unable to build a green house.

After much debate I finally purchased an AeroGarden Elite 6. It was at Costco and the price seamed reasonable since it was the same as the online price without shipping or tax. I figured that it would be a good stepping stone into either AeroGardens or the world of hydroponics. I also purchased a "Kill a Watt" by P3 from NewEgg.com. I'm using this in my classroom to do a study to see how economical they are. We will be keeping an eye on all of the expenses involved.

We started the AeroGarden last week and exactly one week after it was planted everything in the herb kit has sprouted except for the chives. The first basil seed sprouted in only two days. The dill is comming along a little more slowely but it really shot up over the weekend.

It will be interesting to see how it does through the long winter nights here, espesially since I planted it before the longest night.

More later about the cost analysis.

Spinach Pail

2008-05-01T17:48:00.000-07:00

The spinach is doing well and still producing. I would estimate that I have picked enough spinach to fill a 5 gallon bucket so far (not compress). It is interesting that the initial leaves are very tender and melt in your mouth, while the later leaves are little tougher, It still cooks up really nice though and the flavor is amazing. Tonight we had spinach that was ever so lightly steamed.

As you can see from the images below the size of the spinach leaves was amazing.

My hand in front of the spinach leaf.

My hand behind the spinach leaf.

Garlic Temptation

2008-05-01T17:13:00.000-07:00

Since all of the fresh garlic in the house is gone and there is a garlic plant growing in the greenhouse since last fall. It is mighty tempting to harvest it but according to "Garlic Central" below I need wait until the leaves are half brown. And then once picked let it dry for a couple of weeks.

Garden Goodness

2008-04-01T18:53:00.000-07:00

The first few leaves of the spinach plants where harvested today. The spinach plants are looking quite nice. It is interesting that only two of the lettuce seeds sprouted. This exactly opposite of what happened last year. I had only two spinach and lots of lettuce. The greenhouse seems to be working well since I didn't harvest my lettuce last year until a few weeks from how if I remember right.

Looking at the temperatures records for the last couple of days the temperature inside the greenhouse ranged from a low of 31 to a high of 90 while the outside temperature ranged from 21 to 50 degrees Fahrenheit. This is an improvement over the last fall when the minimum temperature difference was only 5 degrees, no it is up to 10. Now I need to worry about seeing if we can keep it from getting to hot since summer is on it's way.

New Life

2008-03-02T15:35:00.000-08:00

I planted spinach and lettuce on the Tuesday before last. I don't see any of the lettuce yet but the spinach is coming along nicely. There are quite a few as you can see from the picture below. The other picture is the basil that I hope to move into the greenhouse when it stops getting so cold at night.

Double Glazing

2008-02-10T16:44:00.000-08:00

This past weekend I finally figured out how to put a second layer of glazing on my greenhouse. The spacing between the layers is about 1 inch but some of the separation isn't that consistent. Looking at the temperature data for the last 24 hours the difference between the inside and outside was at least 2 degrees Fahrenheit and at most about 20 with a maximum inside temperature of 70 and a minimum outside temperature of 30. The only other solar features that could affect the temperature inside was a 30 gallon green garbage can full of water. Hopefully tomorrow I will be turning the air circulation back on if I finish getting the ground tilled.

Here's how I put the double glazing on.
I nailed 3 - 1 3/4 thick boards along the length of the green house. One at the peak, front top edge and front near the ground. In each of these I drilled holes for a 1 inch pipe to set in. This is outside of the existing plastic. I created a pipe framing that covered the existing plastic, this will keep the layers separated. The pipe in the ceiling has a T in the middle of it to help give it a little bit of rigidity. Next I measured the plastic and rolled it out and cut it to length. Folding the plastic back on it's self so that it could easily be laid on top of the greenhouse and stretched out. After stretching it over the back I placed a few staples in it and then stretched it down the front edge. Coming to the back again I added a few more staples in the existing board that secures the plastic. Next I place a strip of wood so that it would secure the plastic to the board near the ground on the front for the greenhouse. After securing this I moved to the back and did the same and secured the plastic to the top board that also holds the pipes in place. Next I carefully worked the ends of the greenhouse so that the plastic was spaced away from the existing plastic. I believe that currently this is the weak link in my design. I'll have to come up with a better way to keep the two layers separated, but until then this should work. Hopefully I'll get some pictures posted soon of exactly how I did this. Until then let me know if you have any questions.

Lots of pictures

2008-01-01T18:35:00.000-08:00

I was finally able to get out and get some pictures of "Greenhouse #2" before I put the second layer of glazing on.

In the photo above the white piece of plywood leaning against the end is not part of the design, it just happens to be there. Behind the plywood is the plywood that is nailed to the wall.
The photo on the left is a view of the other end, this wall is facing due east.
The photo on the right is a closeup of the corner. I tried to round it with a router and chisel as much as possible to help relieve the pressure so that the plastic is less likely to rip.

As you can see from these photos, one piece of plastic stretches from the front wall all the way over and part way down the back wall. The small white square in the upper left corner is where a vent will be installed. I was able to find some 20' wide plastic at Home Depot. I made it long enough, about (8'+16'+8'=) so that it could stretch down and cover the end walls. The left end wall was also remove and covered separately and reinstalled. The same could be done for the front wall if necessary but it would then be hard to secure the plastic to the front wall.

Three quarter inch PVC pipe was used as the support members for the roof. They connect into the front wall with plumbers tape and are secured into some 1 1/8" holes that were drilled in the top of the wall.
As you can see from the photos on the left there were two different ways that I experimented with for securing the pipe to the all.

Each of the PVC pipes are secured to a brace about half way up the roof line and that brace is attached to the back wall with another diagonal brace. Another one should be applied that goes the other direction but this one does a surprisingly good job by itself. The photo at the left shows how the pipe is attached to the main brace. You can also see from this photo that the walls are insulated with white foam.
The brace is attached on top of the pipe so that the metal tape doesn't chaff the plastic.

Each of the walls are connected to each other with two bolts and t-nuts. Thus by removing 8 bolts the whole thing can come apart and be moved. I've moved each of the walls except for the back wall. It is probably getting a bit heavy since it is 16 feet long. Also the back wall has rebar that goes through the bottom of the wall to help keep it from going on a walk like the first one did.

Well that is enough rambling for now. I hope that the pictures help you better understand what I have accomplished so far.

Twin Wall Planning

2007-12-29T17:25:00.000-08:00

Well I decided to plant my first seeds yesterday. Looking at the temperatures for different plants I decided to just see if I could get some herb's started since it is still 20-30F outside. I'll just grow them inside until I can get the greenhouse to warm up. Speaking of the greenhouse I finally figured out a way to add an extra layer. I'm going to build a pipe structure over the top and attach it to the back wall since I can accomplish that with one piece of glazing plastic. I'm trying to get 1 1/2 inch of space between the layers of plastic glazing since that is what I have read is the optimal spacing. At this time the plan is to use 45 degree elbows, 4-way joints, and redwood strips to build the frame for this second layer. I'll post pictures as soon as I get it done. I'm curious to see what this combined with a wall of water will do for the ground temperature inside a wall of water.

Getting ready for an early spring

2007-12-16T08:16:00.000-08:00

I don't know what the weather will do but I am hoping to have an early spring inside of my greenhouse. My goal is to start my seeds in the house on January 2nd. I'm thinking that by the time they are ready to plant I will be able to have the greenhouse warm enough for them. I believe I've figured out a way to cheaply make a double wall of plastic. If I place a grid of 1 1/2" pipe over the current layer and then fasten it down and cover it with a second layer. I should be able to gain some insulation value with minimal expense. I'm also planning on making an insulated door. I'm hoping to do this with my father over Christmas break.

Since I last updated this blog I was able to finish insulating the end wall but I haven't sealed it with foam yet. I did move in some compost, it still needs to be mixed in with the rest of the dirt, and clean up the old plants. The garlic and onions were still grown last time I worked out there but I haven't checked them lately.

Effects of the fan, insulation, & more

2007-11-06T05:03:00.000-08:00

Unfortunately I forgot to turn on the rollover feature of my thermacron so the data never got recorded. In the mean time I was able to pickup some 2 inch foam insulation from HomeDepot, which was cheaper than Lowes. Last night I was able to install the insulation in the back wall. The plan is to fill in the cracks with the spray foam to seal it up really good but I want to get all of the pieces in first so that I don't waste the can of foam. I'm planning on insulating the end wall Wednesday night and hopefully sealing it up on Sunday. I'm also hoping to be able to make an insulated door on Sunday which should really help seal things up.
Until then I've stuck a small utility heater in there that is rated at 1300w. It is set on the lowest setting and is on a timer that turns on and off every half hour during the night so that I'm sure it will not run to much. The heater blows onto the fan which blows onto the plants. Hopefully this will help keep them warm and happy, but not scorched. It seemed to work well yesterday. I'm hoping to post the temperature data from that on Wednesday night.
I've also purchased two dark green 30 gallon trash cans that I plan on putting water in to help collect heat during the day.

Effects of a Fan & Heating

2007-10-31T08:29:00.001-07:00

My plants haven't looked all that great lately so I'm going to try and increase the circulation by placing a small wig-wag fan at the base of my tomato plants near the 60w light bulb. I did this at about 8:00am this morning. I'm hoping to post the results tomorrow or at the latest next Sunday. Also I'm wanting to paint the heat pipes black and insulate the back wall on Sunday to see if I can increase the daytime temperature and temperature storage capacity.

60w Greenhouse Heater

2007-10-30T20:34:00.000-07:00

After doing a little bit of research on my electric bill I determined that it will cost me about $0.02 per day to heat my greenhouse with a $60 bulb running twenty-four hours a day. This seems reasonable. I know that it will not provide very much heat but I'm just looking at extending the season not trying to make it all the way through winter.

Here are the results from each 24hr period.

Date	Outside	Inside	Difference
October 27:
October 28:
October 29:

Conclusion:
It appears that the light was able to produce enough heat to keep the temperature from dropping all of the way in the evening but it didn't appear to make that much difference during the day. Also the days have been warmer so it is also harder to tell the difference. The 28th was warmer overall but it wasn't as sunny as you can tell by the lack of difference in temperature during the late afternoon.

I need to get some more tests because there are still to many variables involved. Such as the tiny hole that needs patched, sealing the door, etc.... So until I can get those items taken care of I will continue to record the information and share it.

Initial Temperature Recordings

2007-10-28T11:23:00.000-07:00

This weekend I was able to get a baseline set of temperatures recorded from my greenhouse. The weather yesterday was sunny with very little wind if any. The temperatures that I was able to record are shown in the graph below. All temperatures are in Fahrenheit and recorded ever 5 minutes using a thermochron. The inside and outside temperature were measured just above ground level in the shade.

Time span: Friday Oct 26 @ 6:00pm - Sunday Oct 28 @11:00am

Outside
	Maximum	52.7
	Minimum	35.6

Inside
	Maximum	71.6
	Minimum	36.5

Difference
	Maximum	18.9
	Minimum	-0.9

Conclusion
This design will warm up but will not hold the heat through the night. In my previous greenhouse I used some 5-gallon buckets to help hold the heat and lightly insulated the back wall and was able to get a temperature positive difference to hold through the night when I put heated water inside the buckets.

What's next
I'm going to try and put an 100watt incandescent light bulb on a timer to come on at a certain time to see how much it can effect the temperature. Also as soon as possible I will be insulating the back wall and patching the small hole in the plastic in the ceiling (manufacturing defect).

Greenhouse #2 revised

2007-10-22T13:40:00.001-07:00

I've done quite a bit of research on better materials to use and decided that I really like Solexx. The only problem is that I haven't figured out a good way to create the roof and have it still be portable. I could screw it to some trusses but then trying to put it back together would be a nightmare. I would like to at least cover the sides with Solexx because they could still be portable.

While roaming Home Depot again the other day I found some construction plastic that was 20' wide. This would work a lot better than the 10' wide stuff I used last spring. It wasn't that expensive so I figured I would give it another try and see if it makes it through the winter. This time I made sure to leave the plastic about 8' long on each end. It turned out really nice because I was able to stretch the plastic all the way from underneath the front wall over the top and way down the back wall. The ends even turned out really nice.

It is a little later than I wanted to cover this but I think I can still get another month out of the tomato plants in their and maybe even a crop of lettuce.

Greenhouse #2

2007-07-22T13:30:00.000-07:00

After the last greenhouse went for a walk I decided that this time I should make it a little bit bigger. My Internet research showed that a larger greenhouse would work better because of it's thermal capacity. This time I decided to make it 8' wide x 16' long by 8' tall. The last one was a little cramped so this would actually give me some room to move around inside. This spring (2007) the weather finally turned nice enough that I could make a nice level spot for it.

Taking into consideration that I may be moving some day I wanted to keep my design as portable as possible. I decided to bolt the walls together so that they could easily come apart. The 8x16 back wall is a bit on the large side but it's still manageable with a couple of people. I liked the solid back wall design of my last greenhouse so I decided to keep that basic design. This time I thought I would try curved roof though. After a couple of days I got it all put together and planted. My goals were to try and get two growing seasons spring-summer and summer-winter. I wasn't able to plant very early this time because the ground hadn't warmed up very well.

I did manage to get a crop of radishes, turnips, and lettuce before I took of on my summer adventures. The problem was that during my summer adventures it got a little hot and baked the plastic covering, which was just construction plastic from Home Depot. When wind started blowing it just shattered and made a lovely mess of the yard. I guess I need more ventilation next time. Since August and September are pretty warm I decided to just leave the covering off and let the two solid walls protect the plants from excess wind.

Back to the drawing board for a new and improved design.

Greenhouse #1

2006-09-22T12:56:00.000-07:00

I got the bright idea to build a greenhouse. I had a couple of tomato plants in my garden and decided to build the greenhouse around them. I wanted to keep the price down so I just went down and picked up some 2x4 studs. The dimensions ended up being about 4' wide by 8' long by 8' tall. It worked pretty well until it got really cold one day and all of the tomato's froze solid. Then during the winter the wind got a little strong and it went for a walk across the yard. I was able to extend the season of the tomato's about a month though so it wasn't all wasted.

During this adventure I picked up some Thermocron's (electronic temperature data loggers). I learned how much of a difference the greenhouse was making and how the air circulation help increase the temperature.