Ohio Birding Forum
This forum is designed to provide a place for discussion of topics that are beyond the scope of the Ohio-birds mailing list (www.ohiobirds.org/publications/emaillist.php).
You are not logged in.
#1 2008-07-06 17:30:27
Cooler Bird Box
I watched Mrs. Bluebird and Tree Swallow put their heads out of the bird house and pant. A cooler bird house was designed to keep temperatures down. It has been compared to a traditional wood house. This cooler house is applicable only to sunny locations preferred by Bluebirds and Tree Swallows.
The house has a one inch thickness of R-7 insulation below the wood top. The inside cavity is 4 1/2 inches square. The roof is 12 inches square to give a protective overhand for sun shading and entrance rain protection. The entrance hole is oval and faces East. On the south and west sides of the house is a covering of reflective aluminum (roofing valley material) to reflect the sun heat. This shiny surface appears gray from above as it reflects the lawn and is not expected to be a concern to the birds. 18 3/8 inch vent holes were placed in the sides just under the roof, and 18 were placed in the floor.
A digital thermometer was positioned latterly in the central part of the cavity 2 1/2 inches below the bottom of the entrance hole. Temperatures were measured and compared with a similar but traditional NABS type box also constructed of 3/4 wood. The conventional box was testing with typical venting (2 3/8 holes in top and also in bottom) and then with high venting ( 12 3/8 holes at top and 12 in floor).
TEST RESULTS
VENTING
On a still day with little breeze the conventional box showed only minimal benefit with the increased venting, 2 1/2 to 3 F degrees. When a breeze came by the temperature did drop, but the amount was not measured.
TEMPERATURES, Deg. F
Conventional Box Prototype Box
Interior Air Temp. 95.7 86.5
Interior Sunny Side 101. 90.5
Interior Shade Side 97. 89.5
Interior Roof Temp. 108. 88.5
Outside Air Temp. 85.5
I am pleased with testing of the prototype box. The increased cost and difficulty of fabrication seem well worth the effort. Both the insulated roof and the reflective side are quite effective in keeping the interior to within about 1 degree of the outside shade air temperature. When we have some hotter weather I will try to get some better electronically recorded data and present it in a multi-point graph. Next year we will see what the birds think of it.
Gene Smith of S.E. Delaware Co.
Last edited by Gene Smith (2008-07-06 17:42:33)
Gene Smith CORRECTED E-Mail Smithhill1@Embarqmail.com
#3 2008-07-07 21:51:55
Re: Cooler Bird Box
Hi Gene,
I agree with Jim. Great work!
There are a couple of other things you might consider measuring at some point. You might try measuring the interior temperature after birds have occupied the boxes (i.e. how does nest material potentially affect the venting). You may also try measuring the temperatures between the two boxes at different points during the day (e.g. morning, mid-day, evening). Does it take longer for the new design to warm up in the morning and does this have any impact on young birds or parents sitting on the nest?
To improve your electronically collected data you might consider purchasing a data logger &/or a thermocouple to measure temperatures from a distance and over an extended period of time.
This is a really cool experiment.
Good luck!
Casey
#4 2008-07-08 07:15:58
Re: Cooler Bird Box
Hey Gene...
How do you think styrofoam (like that used in cheap picnic coolers and bait buckets) would work as ceiling and/or wall insulation for birdboxes ? I think stuff like that can be bought in sheets at craft stores for modest amounts of money.
???
Jim
Let The Horce be with You
#5 2008-07-08 09:35:28
Re: Cooler Bird Box
Hi Jim,
I'm not certain how Gene will respond to your question, but I would caution against using standard styrofoam as an insulating material. The reason is that birds can potentially pick or dig at the styrofoam and flake small pieces off that might get ingested by nestlings or even by adult birds.
A better alternative, if it's available, might be a starch based insulation (like the bio-degradable packing peanuts). Starch based packing peanuts are edible and quickly dissolve in water, making the material somewhat safer if a bird should happen to ingest some. I don't know if it's available as insulation though, but would imagine it might be given the recent trend and interest in green home improvements.
I'll be curious to see what others think.
Casey
#6 2008-07-08 17:48:42
Re: Cooler Bird Box
Thanks for your comments and suggestions. I will include those concerns in my next testing.
I do have a DataQ logger with 8 inputs of the LM34 I.C. sensor, which is pea size. It is quite versatile and can run for days off of a laptop. Just have to get it going again and transfer the software to the laptop, and yes, a long power cord.
Your mention of night time temperatures is interesting. It is cold up there on a clear night even in summer. The insulated roof may help a lot. The first clear night I will take some inside roof temperatures, but it will not be tonight. Will edit this post when I get that info.
There are two kinds of styrofoam insulation, bead and extruded. The bead type is molded in place by hot steam and is not very stable, also absorbs moisture. The extruded type is available in one and two inch thick sheets at Home Depot, for example. It is more stable, but I would still protect in from predators, ultraviolet light, and all animals. I have used Isocyanurate, also available at Home Depot in sheets that have black poly on one side and aluminum foil on the other. Values given for some insulation is as follows:
Glass wool 3.25 R values
Expanded polystyrene, bead type 4.0
Extruded polystyrene 5.0
Expanded polyurethane 6.0 Like Great Stuff
Polyisocyanurate 6.5
Yes, all animals seem to like to tear into styrofoam. Perhaps they do it for the fun of it. An inexpensive and thin protective material for the inside is 1/8 inch Masonite. I plan to protect any outside edges with a couple coats of water base paint.
The reflective aluminum seems to do the job for the sun sides, and it has little weight and bulk. So, I plan to use no insulation on the sides. I will use rough cedar siding boards to cover the insulation on the roof, since the birds like to perch there. And of course drip edges will keep water from running inside the box. Thanks again for your comments.
Gene Smith S.E. Delaware Co.
Last edited by Gene Smith (2008-07-08 17:54:00)
Gene Smith CORRECTED E-Mail Smithhill1@Embarqmail.com
#7 2008-07-09 11:16:06
Re: Cooler Bird Box
How do your temperature readings compare with a natural tree cavity in a sunny, exposed setting?
#8 2008-07-09 15:55:59
Re: Cooler Bird Box
Interesting question ,Kevin. I have been interested in natural cavities mostly from the standpoint of bird choice of nesting site, but temperatures could be a factor of choice. Anyway, I have saved a couple of hollow limb sections beside my firewood pile.
From the standpoint of an actual nesting site I decided the best way was an artificial box made from a large plastic pipe, insulation, and tree bark cemented on the outside. What a cheat. But, that is a separate consideration.
Did you see the post on this site that shows a bluebird at a natural cavity? (Sorry, I cannot find it now). Very small house indeed, perhaps no more than 3 or 4 inches on the outside. Of course we do not know if this was a nest of choice or desperation, but interesting. Has anyone else out there observed a natural cavity bluebird nest? Please let us know.
Meanwhile, I will ready a hollow section and place a sensor in it for my next testing. I will also post the details of the section. Thanks for the suggestion. Gene Smith
Added note 7-13-08
The three test boxes are almost ready and temperature probes are being fabricated. Will test soon. Gene
Last edited by Gene Smith (2008-07-13 10:58:08)
Gene Smith CORRECTED E-Mail Smithhill1@Embarqmail.com
#9 2009-11-13 00:37:52
Re: Cooler Bird Box
A cooler bird house was designed to keep temperatures down. It has been compared to a traditional wood house. But I have not yet see this cooler bird house.
_________________
Refrigerator Water Filter
#10 2010-03-06 15:24:51
Re: Cooler Bird Box
Gene,
What a great idea. I noticed this past summer that many of the birds were panting at my house and my mother's house too. She went to the bird store, but they acted like she was crazy, so I have been looking for alternative bird houses that would be cooler, yet efficient, and feasible. I really haven't seen anything until your post. This is going to be a great project for me. I really appreciate you sharing your idea, material suggestions, and "recipe" to a better birdhouse. Thanks so much!