Topic: AC Case fan for 24 HR Davis FARS shield mod recommendation requests

[fkapp]

Hi guys,

I am planning the next modification for my VP2 which is AC fan along with the 24 x7 Davis kit Ryan at scaled instruments sells.

Is 50 cfm too much flow?
I am located in Buffalo NY, and noticed that on calm/ low wind winter nights my 7714 shield runs few degrees colder than NWS office few miles away. Not super hot climate so dont want to "over correct" and create inaccuracy by too much flow

I am looking at this fan:

https://www.acinfinity.com/component-cooling/axial-ac-fan-kits/axial-1225-muffin-120v-ac-cooling-fan-120mm-x-120mm-x-25mm-low-speed/?gclid=Cj0KCQiA48j9BRC-ARIsAMQu3WQcLMitUa7VDlfs_R7SRznsC5GaHZZ_FFm5H30yezhEJvvnOH9IsRgaAg5gEALw_wcB

Any recommendations out there for Fan would also be welcomed?

Thanks guys as enjoying tinkering and tuning my station

Frank

[CW2274]

This fan is physically too big, you need 80x80x25 mm. Also, the 1800 is rpm's, not CFM, which is at 51, which is overkill. Something between 20 and 40 CFM will do the job easily.

[fkapp]

I noticed my typo just now, thanks for correcting.

Any recommendations?

[CW2274]

Any recommendations?

Not really, there's a million to choose from.

[fkapp]

what dimensions for the fan are needed if 80mm x80mm x25 mm is too big?

[CW2274]

what dimensions for the fan are needed if 80mm x80mm x25 mm is too big?

You DO have a 24hr FARS VP2, right?

[AWL]

Maybe this one IP67 rated for dust and water. https://www.amazon.com/Coolerguys-80mm-80X80X25-Airflow-Waterproof/dp/B07VWLSMN1/ref=sr_1_6?dchild=1&keywords=80mm+25mm+New+Case+Fan+12V+DC+IP55+Waterproof+67CFM&qid=1605575329&s=electronics&sr=1-6.


Doug

[fkapp]

As my original post says I have a VP2 and am in the process of planning a 24x7 FARS which am reading about/ asking for guidance.

Was trying to order the fan needed in parallel to the non solar and battery components from Ryan and ask for some help from those who have already have made this mod.

Apparently that's not the way we roll these days on this forum based on your last statement to CW2274
Read the reams of information and ask a question at ones risk!

Anyways:
From reading through the past topics on the forum around AC FARS 80mm x 80mm x 25mm and less than 40 cfm will work.

My plan will be to order this fan
https://www.acinfinity.com/component-cooling/axial-ac-fan-kits/axial-8025-muffin-120v-ac-cooling-fan-80mm-x-80mm-x-25mm/?gclid=Cj0KCQiA48j9BRC-ARIsAMQu3WQ9ViTeVac7USrtSNz9hi1rGyY1qjfANU6BT2IUk8oTDFLp2MPHS04aAvJAEALw_wcB

and this extension cord to get to GFI in water tight outlet cover I will be installing.

https://www.acinfinity.com/component-cooling/axial-fan-accessories/120in-fan-power-plug-cord/?gclid=Cj0KCQiA48j9BRC-ARIsAMQu3WQzyngBuKaKLBQ460JSPg1tbI-DmWHi1hdWLLbSCtQCQpN0qJMkv0AaAryCEALw_wcB

[CW2274]

Apparently that's not the way we roll these days on this forum based on your last statement to CW2274

Read the reams of information and ask a question at ones risk!

Not sure if that's a dig at myself, but what bothers me regardless is that you come on here asking for help then then ask me if it's not the right size after just telling you the other one was too big.  Seriously? Why in the hell would I do that? I've had my 80x80x25 mm fan in my ISS for 7ish years and it still fits now just like it did when I installed it.

[CW7491]

Being in Buffalo, you may want to pay attention to the fan’s temp rating. Looks like the one you’re looking at is rated to 0F. Even an optimist would probably want something rated colder in a Buffalo winter.

Others may too, but I know coolerguys.com has some 80x80s rated down to -40F.

[fkapp]

Yeah so the first one i listed was too big. I simply asked for a clarification (sorry i missed you listed the 80mm x 80mm x 25mm ) recommendation and didnt appreciate DO comment.

This IS a hobby and am on here exhausted so missed read your response. My comment to you is when someone asks a well intended question or is confused ease up a bit as most people are on here to relax.

Anyways thanks for the input on cfm and dimensions and lets drop this and enjoy the rest of the evening.
 

[fkapp]

Thanks for the guidance on temp rating.

The search continues  and found this:

https://www.coolerguys.com/products/mechatronics-80-x-25mm-ac-115v-fan-uf80b12-bth

[wxmanmhd]

The above fan is what I have been using for two years without any problems and still going strong. My station is located in Moorhead Mn and past 2 years been running with temperatures of -28° to 98°.  Only problem I have had is the screen will frost over on a cold frosty morning so have to brush off the screen to get air flowing again. Snow has never been a problem. 

[fkapp]

Thanks for the help with the fan.

What did you guys use to seal the opening between  the Fan casing and the welded core?

Not sure what is best to avoid moisture collecting in material

Thanks as looking forward to building this out soon.

Frank

[ivano]

Thanks for the guidance on temp rating.

The search continues  and found this:

https://www.coolerguys.com/products/mechatronics-80-x-25mm-ac-115v-fan-uf80b12-bth

sorry, but this fan that I see in the link, should replace the fan that is in the ventilated davis? that is this? [ You are not allowed to view attachments ]  

[AWL]

An 80x80mm will drop right in after you snip the mounting ears down a bit. I used a pair of end-snips. Planning on going in my ISS today to change my temp/humidty sensor. Will try and remember to snap a couple of pictures.


Doug

[fkapp]

Thanks man. Would appreciate it. 
Reading online some guys it sounds like putty or insulate around the case to seal up other than fan. Pictures will help with what works .

Thanks again
Frank

[Ian.]

The link is to a blog I did on upgrading the fan, the reason for it being 12v was my rainbucket heating resistors use 24v, so I already had a low voltage supply at the ISS

https://www.chatteris.biz/blog/davis-fars-upgrade-monitored-pc-fan/

[CW2274]

The link is to a blog I did on upgrading the fan, the reason for it being 12v was my rainbucket heating resistors use 24v, so I already had a low voltage supply at the ISS

How is it possible that your case fan flows almost half as much as the stock fan? Mine's like a vacuum cleaner compared to stock, and it's not sealed in either. The bottom wasn't blocked when you tested was it?

[Ian.]

The link is to a blog I did on upgrading the fan, the reason for it being 12v was my rainbucket heating resistors use 24v, so I already had a low voltage supply at the ISS

How is it possible that your case fan flows almost half as much as the stock fan? Mine's like a vacuum cleaner compared to stock, and it's not sealed in either. The bottom wasn't blocked when you tested was it?

No the plates were all attached on the shield and nothing was blocked.

[CW2274]

The link is to a blog I did on upgrading the fan, the reason for it being 12v was my rainbucket heating resistors use 24v, so I already had a low voltage supply at the ISS

How is it possible that your case fan flows almost half as much as the stock fan? Mine's like a vacuum cleaner compared to stock, and it's not sealed in either. The bottom wasn't blocked when you tested was it?

No the plates were all attached on the shield and nothing was blocked.

Wow. That makes no sense to me.

[fkapp]

Why did you wrap the case with the insulating foam?is this necessary or can just wedge fan case in?

[Ian.]

Why did you wrap the case with the insulating foam?is this necessary or can just wedge fan case in?

The fan neatly sits in the recess when the fan edges have been rounded down a bit, the first time I used a fan I used the foam strip to fill the gaps as I thought this would increase the ‘throughput’ of the air past the sensor via the fan, when the fan fail and I replaced it, I didn’t use the foam as I believe enough air is being drawn past the sensor.

I did a toilet paper test around the shield to prove that their was a slight negative pressure.

[Ian.]

The link is to a blog I did on upgrading the fan, the reason for it being 12v was my rainbucket heating resistors use 24v, so I already had a low voltage supply at the ISS

How is it possible that your case fan flows almost half as much as the stock fan? Mine's like a vacuum cleaner compared to stock, and it's not sealed in either. The bottom wasn't blocked when you tested was it?

No the plates were all attached on the shield and nothing was blocked.

Wow. That makes no sense to me.

When I next service/ replace the fan I’ll repeat the reading in case I’ve made a mistake, the fan is certainly very quiet and even on the bench it didn’t seem as powerful as other fans I’ve taken out of computers, which made it ideal as I’ve read that you can introduce a cooling effect rather than simple ensure an air flow removing static air, but I’m certainly no expert here 😊

[fkapp]

Thanks. AWL how did the iss maintainence go?