All times are UTC + 8 hours




Post new topic Reply to topic  [ 595 posts ]  Go to page Previous  1 ... 36, 37, 38, 39, 40
Author Message
PostPosted: Jul 3rd, '18, 17:30 
Offline
Legend Member
Legend Member
User avatar

Joined: Mar 3rd, '16, 08:46
Posts: 973
Gender: Female
Are you human?: grudgingly
Location: Canberra, Australia
Gunagulla wrote:
>> panel is covered in condensation drips whenever it's running, showing that it's pulling heat out of the air as well as from direct sunlight

Actually, it just means that the panel temperature is below the dew point of the air, so moisture condenses on it ;)


And it has to dump a bit of energy into the panel to condense I know it's not a lot let me cling to my illusions. :-P

_________________
Redcap Builds A System


Top
 Profile  
Reply with quote  
    Advertisement
 
PostPosted: Jul 3rd, '18, 17:36 
Offline
A posting God
A posting God
User avatar

Joined: Mar 9th, '13, 10:44
Posts: 3284
Location: Loomberah NSW
Gender: Male
Are you human?: Im a force of nature
Location: I'm right here
:) ok

However, what you really want to see is condensation around where the water enters the panel, and no condensation where it leaves, showing that the water temperature has risen above the DP :)

_________________
My small AP system: http://backyardaquaponics.com/forum/viewtopic.php?f=18&t=16345
Larger 2nd system: http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=24153
Solar powered Gunagulla Organic Garden
Fruit +Loomberah Wx
http://gunagulla.com


Top
 Profile  
Reply with quote  
PostPosted: Jul 3rd, '18, 20:14 
Offline
Legend Member
Legend Member
User avatar

Joined: Mar 3rd, '16, 08:46
Posts: 973
Gender: Female
Are you human?: grudgingly
Location: Canberra, Australia
Gunagulla wrote:
:) ok

However, what you really want to see is condensation around where the water enters the panel, and no condensation where it leaves, showing that the water temperature has risen above the DP :)


...Huh. Well, I know the condensation isn't even across the panel; I must have a look at it tomorrow while it's running to see if there's less/none over on the exit side. (I want to say there is less there, but I could be doing some wishful misremembering. :lol: )

_________________
Redcap Builds A System


Top
 Profile  
Reply with quote  
PostPosted: Jul 10th, '18, 00:00 
Offline
Legend Member
Legend Member
User avatar

Joined: Mar 3rd, '16, 08:46
Posts: 973
Gender: Female
Are you human?: grudgingly
Location: Canberra, Australia
Nope, there is no real difference in the amount of condensation across the panel, unless you look at it right after a bunch has dripped off. :funny1: To be fair, it's humid enough in there that it'd have to get really hot before it got above the dewpoint.

We had a lovely sunny day on Sunday (appropriately enough!) so even though it was bloody cold and didn't get above 12 C outside (I don't believe it, it was never above 10 anywhere I was!) the water temperature hit 17.5 C and the fishies were hungry!



_________________
Redcap Builds A System


Top
 Profile  
Reply with quote  
PostPosted: Jul 10th, '18, 06:53 
Offline
A posting God
A posting God
User avatar

Joined: Mar 9th, '13, 10:44
Posts: 3284
Location: Loomberah NSW
Gender: Male
Are you human?: Im a force of nature
Location: I'm right here
The dew point is always less than the air temp (or equal in fog=100%RH), so if your water is above air temp then it is certainly above dew point, and there shouldn't be any condensation!

_________________
My small AP system: http://backyardaquaponics.com/forum/viewtopic.php?f=18&t=16345
Larger 2nd system: http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=24153
Solar powered Gunagulla Organic Garden
Fruit +Loomberah Wx
http://gunagulla.com


Top
 Profile  
Reply with quote  
PostPosted: Jul 10th, '18, 16:19 
Offline
Legend Member
Legend Member
User avatar

Joined: Mar 3rd, '16, 08:46
Posts: 973
Gender: Female
Are you human?: grudgingly
Location: Canberra, Australia
Gunagulla wrote:
The dew point is always less than the air temp (or equal in fog=100%RH), so if your water is above air temp then it is certainly above dew point, and there shouldn't be any condensation!


My water is well above outside air temp, and often above the air temp inside my hoop house as measured at the level of the growbeds. The daytime air temp inside my hoop house at the top of the arch where the solar panel hangs, on the other hand, gets a lot warmer! Like, warm enough that if my water was warmer than it I would have fish soup. :shock: My glasses steam up when I first go in on sunny days, and if I stay in there for more than a few minutes my hair starts going frizzy from the humidity. :laughing3:

The plants love it, the nasturtium is still working on its world takeover and we've moved my husband's bonsai in there. The horseradish is really the only plant that's getting unhappy; it's on the outside of an end growbed and probably gets the coldest nighttime temperatures. It's dying back for the winter and I plan to harvest it soon.

_________________
Redcap Builds A System


Top
 Profile  
Reply with quote  
PostPosted: Jul 12th, '18, 15:33 
Offline
Legend Member
Legend Member
User avatar

Joined: Mar 3rd, '16, 08:46
Posts: 973
Gender: Female
Are you human?: grudgingly
Location: Canberra, Australia
I was curious about actual numbers, so I checked today. :think: It was pretty darn cold out (about 8 C at the time) and not sunny; the temperature down at growbed level inside the hoop house was 15.6 C, and the same probe read 23.2 C up next to the heater panel (in the shade).

_________________
Redcap Builds A System


Top
 Profile  
Reply with quote  
PostPosted: Jul 16th, '18, 07:08 
Offline
Legend Member
Legend Member

Joined: Mar 29th, '15, 16:06
Posts: 665
Gender: Male
Are you human?: yes
Location: Austalia, SA Pt lincoln
Mel,,excuse me using your thread but its all relative.

I now have approx .5 kilometer of 10 strand solar pool piping and about .3 of 6 strand, have the manifolds arriving from Ebay this week so building should start soon, not expecting big improvement as I still only have bird netting and shade cloth covering my house....

but with yours what pump are you using?.... please

_________________
All vegies would be nicer to eat ......if they tasted like BACON


Top
 Profile  
Reply with quote  
PostPosted: Jul 16th, '18, 20:01 
Offline
Legend Member
Legend Member
User avatar

Joined: Mar 3rd, '16, 08:46
Posts: 973
Gender: Female
Are you human?: grudgingly
Location: Canberra, Australia
No worries Tonzz, it's all good! :thumbleft:

I'm using a Pond One Shark 7500; it's overpowered for the job and I'm using a t-junction and a tap to divert a lot of the flow, but two sizes smaller than it was definitely too weak. You need a slow steady flow and it takes a lot of oomph to get it because the panels add some serious drag.

My panel is 0.7m deep and 3.8m long, so 2.66m2 surface area. The guys who sold it to me said that a flow of around 7-10 L/minute would be best, but so long as it was coming out faster than a trickle and had a perceptible difference in temperature from the input water it should do OK. If you've got more total surface area you'll need faster flow; when we were discussing using three panels they were talking about 21 L/minute.

Even though you'll be losing a lot of the added heat at night, hopefully it'll be noticeably better than without it!

_________________
Redcap Builds A System


Top
 Profile  
Reply with quote  
PostPosted: Jul 17th, '18, 06:58 
Offline
Legend Member
Legend Member

Joined: Mar 29th, '15, 16:06
Posts: 665
Gender: Male
Are you human?: yes
Location: Austalia, SA Pt lincoln
Thanks Mel, gawd more $$$$s required for 'development'. :laughing3:

_________________
All vegies would be nicer to eat ......if they tasted like BACON


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 595 posts ]  Go to page Previous  1 ... 36, 37, 38, 39, 40

All times are UTC + 8 hours


Who is online

Users browsing this forum: Baidu [Spider] and 13 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

Powered by phpBB® Forum Software © phpBB Group
Portal by phpBB3 Portal © phpBB Türkiye
[ Time : 0.070s | 20 Queries | GZIP : Off ]