Too hot, air vent possible?

[hyper7]

It's been pretty damn hot around here recently (100° heat index, which for northern Ohio is crazy hot) and I'm looking to cool down a bit inside, specifically around my feet.

 

I've read that others have suggested turning the heater off and turning the fans on to move some air around, but mine seems to just put out hot air regardless of the cable - I need to take a look and make sure it's actually closing all the way.  I would expect the air to be "ambient" temperature, but mine is HOT.

 

Other things I've read are people remove the cover on the pedal box for more airflow - does that actually help? I would think it would just pump hot air from the engine bay into the foot well?

 

My next thought was trying to fab up some ducting to go from the vents in the hood down to my feet - something that could be removed during the cooler months.  Has anyone done anything like this? I couldn't find anything, but thought it's gotta be something SOMEONE has thought of....

[CBuff]

Interesting read on the topic

 

https://www.caterhamlotus7.club/forums/topic/57793-footwell-cooling-strategy/

 

[hyper7]

I'll check that out, thanks

[hyper7]

Definitely some interesting ideas there. I'll start with fiddling with the heater to make sure it's actually closed when I think it is, then will need to look into insulating the engine side of the foot well. Sounds like that's where most of the gains happen.

[Slonie]

I've definitely seen some inventive strategies around the internet, from a 4" or 5" PC-style fan (and a hole cut/drilled in the top of the pedal box) to pull air out of the footwell (and into the engine bay), to just sticking a fan in front of the driver's seat to circulate air in the area. I've not been totally convinced to do either of those but I was thinking a little duct installed on the sill might be able to direct some ram air into the footwell.

 

Seems to be an ongoing battle for 7 drivers though. I've actually had my heater valve open since bleeding the cooling system last year, maybe it's finally time to close it to get some relief now that temperatures are up.

 

 

[Slonie]

Here's the guy who installed a fan on the top of the pedal box (video on Facebook, sorry)

 

https://www.facebook.com/groups/2039770472972788/posts/4091715377778277/

 

He reports that it's been installed for four summers and makes a big difference. He added the perspex cover to keep cold air from flowing back in over the winter (though I don't know how much of a problem that would really be). 

 

 

 

Another edit: The thread linked by CBuff above has some interesting ideas and testing, too bad all the pictures and links are dead. Seems like several people had the same (lowest effort) idea of a funnel scoop and dryer hose, it's just a matter of doing it in a way that maintains some semblance of dignity in the install...

Edited June 27 by Slonie

[IamScotticus]

some ventilation on top of the pedal box is good as it prevents condensation collecting and rusting the frame there.  It happened to me.

Edited June 27 by IamScotticus

[hyper7]

I really like the idea of the CPU fan on top of the pedal box.  Seems like an easy solution that requires minimal modifications. 

[hyper7]

Yeah as I'm looking into that, I like the idea more and more.  I'll pick up a fan and a temperature switch to automatically turn it on with it's hot.  I think this will work perfectly.

 

I'll report back once built and tested 😎

[MV8]

Header wrap, trim to fit firewall thermal blanket cowl to floor to tunnel entry and in front of the firewall, heater blower on high but the heater valve closed.

Edited June 28 by MV8

[hyper7]

Had the front off today and yeah, the heater was no where near closed. I adjusted it the best I could, but it still doesn't quite close all the way via the switch, so I manually closed it all the way, much cooler air coming through the fans now.  

 

Also, there's the existing hole on the pedal box cover for access to the gas pedal cable..looks like the perfect spot for the CPU fan, no cutting required.

[panamericano]

Put a genuine plumbing valve in the hot water line to the heater.  Close in spring.  Open in fall.  Pretty common practice on CMVs.

[Slonie]

I closed my heater valve for the first time since bleeding the system and blew not-as-hot air at my feet. Helped, for a while anyway. (We’re experiencing 90ish temperatures right now here)

[hyper7]

I was out last night in the car, and was thrilled that the closing of the valve seemed to work! And then was out late and it was so damn cold I had to reach under and open the valve back up lol.  I guess I'm glad I have the heater after all!

[pethier]

On 6/28/2025 at 5:51 PM, panamericano said:

Put a genuine plumbing valve in the hot water line to the heater.  

I did that on my Europa.  None of the stuff for the heater was in the car when I got it, except the heater cores and the steel pipes inside the frame.  The car was from Oahu.

 

I put a plumbing valve in one of the heater hoses I fitted under the dashboard to connect the heater cores to the steel pipes.  Even if I had the original parts, there was nowhere to put the cable.  The original center armrest had been replaced with koa wood.  There were no cables for heater valve or choke.