Heat Extraction from Observatory

[glend]

How are people managing heat build up inside an observatory during the day? Any ideas for solar ventilators, shed fans, etc that can be used to extract heat from the Obs?

[Den]

Hi Glen,

I am thinking of using one of these. So far my tank is not heating up as much as I thought.
Den

[ZeroID]

Mine hit 34* yesterday, unusual over here. I'm going to open up a few mesh and grill protected vent holes up near the roof line and let the thermals take care of it.

[glend]

It was 37+ outside here yesterday and the internal temp was higher for sure - I need to get a thermometre in there. The storm that followed late in the day produced wind driven horizonal rain which woud probably have been diven through the louvre type vents. I can easily put in some floor vents as its on a raised deck but the top vents ( to use convection) is the problem. Whirlybirds ( in my experience) leak and allow debris inside. I am looking at the solar powered roof ventiators like this one:


http://www.ebay.com.au/itm/Solar-Wall-Exhaust-Fan-Vent-Boat-Caravan-Greenhouse-/251835822588

The solar panel seems to be able to be relocatable and I can mount the fan unit on the vertical face of my skillion roof, which should extract heat from high up. I think it would be posible to fashion a 'storm cap' of some sort, like those used on boat cabin ventilators.

There are also many boat cabin ventilation solutions that might work very well for simple convection solutions, like this one:

https://www.whitworths.com.au/main_itemdetail.asp?cat=156&item=92163&intAbsolutePage=1

[ZeroID]

A simple box sheild with side ports will protect a vent. Louvred vent with an external metal box over it with sides open. Make the box about twice as wide as the vent or more. I'd add some fine grill behind the louvre vent for creepy crawlies. Box needs to be deeper than te bottom of the vent hole so any moisture just runs out.

[astronobob]

Interesting concepts there Glen.
Im about to start a home roll-away-Obs and was going to go with a 12v fan under a wirly gig, thinking twice now as you mention they can leak under wild weather.
Im liking Brent's ideas tho - sounds rather feasible for a chap on a budget :thumbsup:

[byronpaul]

Glen,

I recently got one of those Solar Power vents off ebay for the purpose of installing it in my Tin Shed Observatory.

Thus far, I've just tested it by leaving it outside in the sun and running it 24x7 for about 1 month. No problems there. Very quiet and fan just kept going.

The fan isn't overly strong, but it certainly moves some air. It also easily runs all night it left on. Whilst I'm aiming to use it to reduce Heat in Summer, I'm also hoping it would remove some internal moisture in winter.

I don't think it's going to be a total solution, but it should help. I just need to cut the hole and install it.

Regards,
Paul

[ZeroID]

Budgets are important. If you can do 1 bit cheap that leaves more budget for better bits you can't make. :thumbsup:
Just a simple piece of ply or similar hung in front of the louvre will do it. My Ob leaks so much air in around the bottom that heat would just rise and pour out two louvres. One at either side would also allow the prevailing breeze to push through and carry it out also.
I've found solar powered devices seem to last about a year before the batteries give up.

[astronobob]

Sounds good Brent, given me some ideas, my roll-away-obs, only small, more like an oversize cover with some shelving down low (under scope when in place) for Lappy etc, being on wheels will have about an inch gap to the ground - with a wirly gig allowing for convection currents, tho having a fan will aid in air movement during SunDown to excellerate cooling the rig prior to astronomical twilight :thumbsup:

@ Glen - I assume you Obs is a sealed unit with out 240v ?

[5ash]

The roof on my observatory is a hexagonal pyramid riding on 6 ladder bearings in a "L" section ring. The roof overhangs and has a large..... Gap under it allowing lots of airflow. Scope is covered , surrounds sprayed with surface spray . No problems with creepy crawlies , when the roofs open they can get in anyway.i think too much effort is put into sealing observatories.
PS its been up for 13 yrs no issues.

Regards philip:shrug:

[sheeny]

I've been running a solar powered vent fan in the roof of my POD since I got it. It had dropped the peak temperature during the day by about 10°C.

Solar vent fans are common in boats, so you can readily source them from marine outfitters and chandlers such as Whitworths.

Al.

[glend]

Bob yes the obs is sealed except for the gap around the pier and the rear skillion roof overhang. I left those gaps to provide convection flow and they work pretty well and are still waterproof so far.

I installed one of the solar wall mount fans from ebay, its mounted up high near the peak front face of the skillion roof. I can feel the hot air being exhausted thrkugh the vent, and inside I can feel the cool air being drawn in from the pier floor gap (the obs is raised on a stump foundation so there is underfloor circulation. Seems to be working fine. The cheap unit I bought does not have a battery but that's ok it still runs until the sun goes down.

[astronobob]

Sound like its working really well Glen - good stuff :thumbsup: