20' Container Observatory

[mtodman (Matt)]

Well, after years of planning, my wife and I have just taken the plunge and bought a proprty on acres in Arcadia which is about 50km north of Sydney. Her motivation is a tree change (albeit one still within the greater Sydney area) whilst I only had 1 criteria, somewhere to build an obs. OK, 50km out of Sydney doesn't give me pitch black skies but it's bound to be an improvement on my current location which is close to the geographic heart of Sydney.

I'm currently investigating the idea of modifying a 20' shipping container as seen in the attached sketchups. The reason being that my brother-in-law owns a business that sells & modifies shipping containers. He seems to think such a project should be pretty straight forward.

My main concern is the heat factor in summer. Shipping containers are notorious for getting very hot inside. I'm hoping that this can be overcome by adequate motorised ventilation, raising it ~30cm off the ground and by using a suitable exterior paint..

I'd be interested to know if anyone has managed to tackle the issue of an overheating obs?

I'm meeting up with my brother in law on Friday to come up with a design so that work can begin. I'd appreciate any comments / suggestions that anyone may have re such a project.

I'll post updates as this progresses.

Cheers, Matt.

[TrevorW]

Ventilation in sides and a whirler vent on top you could probably even insulate with particl board and sisulation

by the way 20" (inches) is small I assume you meet feet

[mtodman (Matt)]

Feet, Yes. Thanks for picking that up.

I was considering a 2nd hand refrigerated container (reefer) and removing the refrigeration unit however they cost a lot more and are harder to come by.
Your idea of interior walls with insulation may work well though.

[TrevorW]

You need to be able to remove hot air build up much like you would from a roof space to make it bearable in the summer months

ventilation slates at ground level and the whirler vent on top would do that

although metal would loose heat rapidly at night

[mtodman (Matt)]

Thanks again Trevor. I like the idea of ventilation in the floor. I'll raise it with my brother-in-law when we're discussing the design details.

[scagman (John)]

You could put in a air con, This would also reduce cool down time on your telescope.

[jenchris (Jennifer)]

Ok - roof - air space a false roof. Can be sail cloth over battens - just something to keep the direct sun off.
Sides - paint with reflective solar paint (about 40% drop in radiation.
Then buy sheets of styrofoam from an outlet - they're very cheap - 1200 x 2400 x 12mm will cost about 7 dollars - go for about 15mm easy to work and Delta is about max for efficiency. Stick them to the inside and cover with 4mm ply (also less than 10 dollars a sheet.)
Stud adhesive is very efficient.
If you drill holes in the lower area and vent the top, make sure you put some serious rodent gaurd on it.

[M_Lewis (Mark)]

Do what landrover did with their safari models....put a tropical roof on top of it. Only has to be 6" above the top, and you can get the foam backed colourbond already bonded.

[mtodman (Matt)]

Jenifer, Mark & John. Many thanks for the suggestions. You've raised some interesting ideas.
Yes. I agree that placing a shade cloth just above the roof would act to avoid direct sunlight. I just need to think how to do it without obstructing the sky too much when the roof is rolled back.

I'll also look into internal insulation as suggested. I imagine it wouldn't be difficult to attach during construction.

If all else fails, I can look at a small portable AC unit. I may need to setup a solar power cell or 2 to keep it going.

Cheers

Matt

[okiscopey (Mike)]

Interesting idea Matt. The wall heights seem to be a bit restricting though ... most folks have fold-down wall sections or other solutions for viewing lower altitudes.

[gregbradley]

A/Cs use a lot of power. Solar cells wouldn't handle it.

Be interesting if you can make it work. I think there are some serious barriers there.

Are you planning to mount the scope on the steel floor?

Generally the base needs to be separated from the general floor to isolate it from vibrations. Like a concrete pier set deepish into the ground and separate from the floor. I dug a 1 metre deep hole and its about 800mm square with lots of steel in it and then poured concrete in it and it extends about 100mm above ground. That seems totally stable and no vibration effects.

The main worry would be heat. You don't want to fry your scopes in summer.

When I built my observatory I lined the roof and walls with Aircell Insulbreak insulation. I sprayed it matt black on the inside.

In really hot days I was pleased to find the inside of the observatory to not be that hot. That is despite being colorbond roofing and walls.

The insulation ideas are critical. A couple of whirlybirds with mesh base and a solar powered vent would be good. The foam roof with something on top sounds good advice as well. You can buy colorbond sandwiched foam roofing panels. Much like used in coolrooms. They'd also be rigid and would make it easier to build a roll off roof. Put a 100mm C purlin on top and stitch some of those together and fix some wheels and you got a roll off roof.

Greg.

[mtodman (Matt)]

Thanks Mike & Greg for your comments & suggestions.

Mike, re the wall heights, this is something I'm going to discuss with the container modders. I have a few ideas, the most desirable (ie expensive) being a dome - perhaps something like this http://www.telescope.org/infopage.ph...fe_Observatory but I may be able to get them to design a curved roof to gain some extra OTA elevation. It would at least provide me with a better view of the Eastern & Western horizons.

Greg, I'll be using a 30cm diameter cement pier with a 1 tonne (1 cubic metre) base as per my current pier. I'll have a raised floor in the sectioned off area of the container with a 35cm dia hole in the centre of the floor. This way, when I get the container delivered, the crane will be able to lower it over the pier and onto concrete blocks at each corner of the container (30cm above ground level).

I'll have power running to the obs so I could power an AC unit from there if need be. I would only use this as a last resort if all else fails.

Cheers

Matt

[CDKPhil]

I just bought a Mini cube 6' x 6' container, but for a totally different reason.
One thing you will have is a very secure observatory. The average thief will find it very difficult to get into.
good luck with your project.

cheers
Phil

[qld]

hi, a few years ago i converted a 40 ft container into a dwelling on our present weekender farm until we completed the construction of the house, i found out that in winter it cooled down very quickly and needed internal heating and in summer with the doors closed it was an oven. to overcome these issues (and successfully) i carried out the following modifications.
1. installed sliding alluminium windows with fly screens to allow for air flow in summer and keep out the bugs(they love it inside),conversely in winter with the windows shut and a curtain drawn temperature was ok.
2.We carpeted the wooden floor to dampen noise and it was easier to keep the whole interior clean and tidy ...and civilised
3.lined the walls with reflective builders aluminium sheet(buy it by the roll) and then fitted timber battens on the internal walls to which were nailed pine coloured plywood sheets (threeply)which i purchased from Mr plywood
4.12v lighting serviced by solar did the job ,today i would do the same only use leds .In your case combinations of red and white in strips along the walls placed as downlights.
5.the internal roof was lined with 50mm thick styrofoam squares which were cut to fit tightly between the metal battens in the roof,white (pre covered) plywood sheets were then applied as a ceiling also from mr plywood.
6. a small potbellie stove provided all the heat at night as the farm is located in the southern highlands where it gets very cold during winter.
7the external roof was protected from the problem of water pooling(which promotes rust and eventually destroys the container) by installing a false zincaloom roof secured with battens and held fast with wire rigging . the false roof added significant temp controll to the interior of the container as it provided air flow and further insulation.
8.Mr Plywood also provides the skirting boards and cornices that go with the plywood as a seperate item these can also be purchased from Bunnings.they are made of poly material and very easy to install. incidently from memory the plywood sheets are almost the height of the internal height off the container and are joined with a plastic joiner which is the same colour as the skirting board and cornice.
The container is still used to this day by my children and their friends as a bunk house and myspace room and its comfort is excellent. For an observatory i would do all of the above and instead of rolling the roof away from the container and using up valuable space ans dollars i would roll the roof back over the other half of the container all you need in a grinder and a welder to cut open the roof (keep the cut out and re use it with a frame to fabricate a roll on/off.roof

When locked up the great feature of the container is that its dust proof water proof vermin proof and secure.
Excluding the cost of the container and using seconds where possible this should only cost you about $1500.00.
IF MY WIFE HAD NOT PLANTED TWELVE RADIATA PINES AROUND THE BOX I would have converted it to an observatory, but alas this cannot be undone so i house a 16 dob inside it which i roll out on good nights when i get the urge. good luck with your project i can assure you you are on the right track.
qld.

Originally Posted by mtodman

Thanks Mike & Greg for your comments & suggestions.

Mike, re the wall heights, this is something I'm going to discuss with the container modders. I have a few ideas, the most desirable (ie expensive) being a dome - perhaps something like this http://www.telescope.org/infopage.ph...fe_Observatory but I may be able to get them to design a curved roof to gain some extra OTA elevation. It would at least provide me with a better view of the Eastern & Western horizons.

Greg, I'll be using a 30cm diameter cement pier with a 1 tonne (1 cubic metre) base as per my current pier. I'll have a raised floor in the sectioned off area of the container with a 35cm dia hole in the centre of the floor. This way, when I get the container delivered, the crane will be able to lower it over the pier and onto concrete blocks at each corner of the container (30cm above ground level).

I'll have power running to the obs so I could power an AC unit from there if need be. I would only use this as a last resort if all else fails.

Cheers

Matt

[qld]

i forgot to add that besser bricks placed on concrete slabs raising the container off the ground is a must dont use sleepers they rot and attract white ants. i would also not cut a door into the side as your drawing suggests but rather keep the sealed doors of the container it gives you greater access and of course the other features of security etc.
qld

Originally Posted by qld

hi, a few years ago i converted a 40 ft container into a dwelling on our present weekender farm until we completed the construction of the house, i found out that in winter it cooled down very quickly and needed internal heating and in summer with the doors closed it was an oven. to overcome these issues (and successfully) i carried out the following modifications.
1. installed sliding alluminium windows with fly screens to allow for air flow in summer and keep out the bugs(they love it inside),conversely in winter with the windows shut and a curtain drawn temperature was ok.
2.We carpeted the wooden floor to dampen noise and it was easier to keep the whole interior clean and tidy ...and civilised
3.lined the walls with reflective builders aluminium sheet(buy it by the roll) and then fitted timber battens on the internal walls to which were nailed pine coloured plywood sheets (threeply)which i purchased from Mr plywood
4.12v lighting serviced by solar did the job ,today i would do the same only use leds .In your case combinations of red and white in strips along the walls placed as downlights.
5.the internal roof was lined with 50mm thick styrofoam squares which were cut to fit tightly between the metal battens in the roof,white (pre covered) plywood sheets were then applied as a ceiling also from mr plywood.
6. a small potbellie stove provided all the heat at night as the farm is located in the southern highlands where it gets very cold during winter.
7the external roof was protected from the problem of water pooling(which promotes rust and eventually destroys the container) by installing a false zincaloom roof secured with battens and held fast with wire rigging . the false roof added significant temp controll to the interior of the container as it provided air flow and further insulation.
8.Mr Plywood also provides the skirting boards and cornices that go with the plywood as a seperate item these can also be purchased from Bunnings.they are made of poly material and very easy to install. incidently from memory the plywood sheets are almost the height of the internal height off the container and are joined with a plastic joiner which is the same colour as the skirting board and cornice.
The container is still used to this day by my children and their friends as a bunk house and myspace room and its comfort is excellent. For an observatory i would do all of the above and instead of rolling the roof away from the container and using up valuable space ans dollars i would roll the roof back over the other half of the container all you need in a grinder and a welder to cut open the roof (keep the cut out and re use it with a frame to fabricate a roll on/off.roof

When locked up the great feature of the container is that its dust proof water proof vermin proof and secure.
Excluding the cost of the container and using seconds where possible this should only cost you about $1500.00.
IF MY WIFE HAD NOT PLANTED TWELVE RADIATA PINES AROUND THE BOX I would have converted it to an observatory, but alas this cannot be undone so i house a 16 dob inside it which i roll out on good nights when i get the urge. good luck with your project i can assure you you are on the right track.
qld.

[Stu Ward]

Looking at the drawings, the available sky looks very restricted,

The side walls are too high.

Stu

[ZeroID (Brent)]

Originally Posted by Stu Ward

Looking at the drawings, the available sky looks very restricted,

The side walls are too high.

Stu

Taller pier and a false floor ..?

[gregbradley]

2.2 to 2.3 metres is a good wall height for an observatory.

Greg.

[Paul Haese]

Matt, anything is possible if you put your mind to it.

I agree with Greg about using the insulbreak by Aircell. Good stuff, we use it in the building industry and it does help.

I deliberately did not put any windows in my observatory. Sunlight enters this way and heats up the area faster. Using slots in the floor or wall sides with a whirly bird is a good idea. False floor is going to work for you too. Having a warm room looks like a pleasant idea. Considering an extension to my obs with a warm room too.

Plant nice thick scrubs around the west and east walls too, this helps with creating a micro climate which ultimately keeps the heat out.

Certainly a good use of an very rigid structure and no building necessary. It took me nearly a year to totally complete my observatory, and there is still stuff I would like to do. By taking this approach you will save yourself a lot of construction time.

I like the idea.

[mtodman (Matt)]

Thanks very much to everyone for their comments, suggestions and words of encouragement. I spent this afternoon at my brother-in-law's container yard and with the assistance of his modifications designer we made some good progress.
The main issue with shipping containers (heat dissapation) will be handled by a combination of reflective solarguard paint (white), 50mm foam insulation panels on the roof sections and the installation of a fan assisted whirlybird (which will pull in fresh air from vents in the floor). With this combination, we would hope to maintain sensible internal temperatures. Should that fail, then we still have the option of using a portable AC unit.
The idea of a sliding roof has now been replaced by a hinged design with the 2 halves of the observatory roof working in a clamshell type arangement. The attached partially completed pic shows the basic idea (it's obviously missing the other half of the roof / wall piece). This roof design was chosen for 2 reasons. Firstly, it achieves horizon - horizon views in the Eastern & Western directions (ie, the 2 sides of the container) and more importantly, it will be much cheaper than the original roll off roof design. The drawback is that the lower Nth and Sth altitudes will be obscured. I'll need to figure out the extent to see if this will be acceptable.
The floor of the telescope section will be 600mm higher than the "warm room" with gives plenty of potential storage space below the raised floor. It also gives me ~1800mm of head room when the roof is closed.
Based on Paul's comment regarding windows, I'm happy not to install any in the obs. It will reduce the internal heating and save construction $$$.

I still need to figure out the electrical and data cabling requirements but I don't think that should poose any problems.

I'll post updates as things progress.

Cheers, Matt.