Heater box firewall penetration

[jneves]

I have a 6A without any heat. Picked up all the parts needed and now I'm working through the plan to install. The only file I have in the digital plans references the 7 heater box location about center of firewall. Problem is my 6 was built with the battery behind the firewall in the center so that location does not seam to work. I've seen a few other locations but from the pics and the info I could not tell if it was a 6, 7 or 9 I was looking at.

So the question is to any builders, where would/have you located the heater box on a 6 with the battery mounted inside the cockpit, centered at the firewall?

 

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A quite normal place is in the lower area of the co-pilots side of the firewall if your muff is on that side or really anywhere you want.
Think of ease of duct runs and muff and the location will become more obvious.
My three cents worth Art

 

[jneves]

Thanks Art, I went down this afternoon, took off the cowl and came to the obvious conclusion. Co-pilot side in the one good spot away from fire wall bracing, clear of obstructions and all. Routing the scat is going to be fun, but I really only have one cross pipe from the exhaust with enough clearance to get the muff on it.

Thanks for the note!

 

[PaulvS]

Assuming that you will use the heater box that has the bowden control cable on the aft side of the firewall, consider also how the knob/cable will be mounted and routed when you locate the opening and orientation of the box.

The standard heater box that Vans sell is aluminum however Spruce sell a stainless equivalent that will offer better protection in case of fire in the engine bay.

 

[RV6_flyer]

A quite normal place is in the lower area of the co-pilots side of the firewall if your muff is on that side or really anywhere you want.
Think of ease of duct runs and muff and the location will become more obvious.
My three cents worth Art

Assuming that you will use the heater box that has the bowden control cable on the aft side of the firewall, consider also how the knob/cable will be mounted and routed when you locate the opening and orientation of the box.

The standard heater box that Vans sell is aluminum however Spruce sell a stainless equivalent that will offer better protection in case of fire in the engine bay.

I mounted mine on the right hand side, installed a soft deflector so all the head did not go on the PAX.

Back 30-years a building, the aluminum box Van sells is all that was available. I modified it with a stainless door and stainless hinge. Has worked well for 3,500 flying hours over the past 25-years.

My RV-8 project has the more expensive all stainless box as I would rather have something more fire resistance than aluminum.

 

[cajunwings]

Heater Box

Consider also where all the hot air is flowing when the heat is off. I will exit the cowl of course with the rest of the airflow, but might heat up something you don’t want to heat up on the way. I made a deflector for the heater box on the firewall side to keep the excess hot air away from my firewall mounted oil cooler.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

 

[DanH]

+1 on stainless boxes.

There are boxes out there with aluminum bodies, a stainless hinge, and a stainless door...assembled and/or attached with aluminum rivets, and held closed with an aluminum arm on the back of the door.

Take the time to find that wayward bag of SS pop rivets, or order some MS20427F3's. Use a stainless arm on the door. Be sure the cable sheath is held with steel hardware.

 

[jneves]

Assuming that you will use the heater box that has the bowden control cable on the aft side of the firewall, consider also how the knob/cable will be mounted and routed when you locate the opening and orientation of the box.

The standard heater box that Vans sell is aluminum however Spruce sell a stainless equivalent that will offer better protection in case of fire in the engine bay.

Thanks for the tip, I'm going to run a linear actuator instead of a cable, simple system on a potentiometer. Used to use this setup in the marine industry/12volt accessories world.

 

[jneves]

+1 on stainless boxes.

There are boxes out there with aluminum bodies, a stainless hinge, and a stainless door...assembled and/or attached with aluminum rivets, and held closed with an aluminum arm on the back of the door.

Take the time to find that wayward bag of SS pop rivets, or order some MS20427F3's. Use a stainless arm on the door. Be sure the cable sheath is held with steel hardware.

Everything I picked up that sits on the hot side of the firewall is SS, parts and hardware.

Read enough to know SS is the safe way to go.

 

[DanH]

Everything I picked up that sits on the hot side of the firewall is SS, parts and hardware. Read enough to know SS is the safe way to go.

Be cautious about the "cold" side too, because given an engine compartment fire, none of it is cold for long. Anything aluminum will be down to less than 10% of original strength in two, maybe two and a half minutes, all by conduction, no fire exposure. Cable fixation and the arm on the back of the door should be steel if we expect them to hold the door closed.

 

[QuixoteAg]

Thanks for the tip, I'm going to run a linear actuator instead of a cable, simple system on a potentiometer. Used to use this setup in the marine industry/12volt accessories world.

sounds like a great idea to me - i'm still building my 6 and may copy you. mind sharing the hardware choices you're making and the source?

 

[jneves]

sounds like a great idea to me - i'm still building my 6 and may copy you. mind sharing the hardware choices you're making and the source?

After going back and forth with building my own control module and using an off the shelf actuator I just decided to order up the TCW control valve servo kit from ACS. If I made my own I would save some money, but being that I lack extra time and don't mind making it up with some $$$, I went with the higher cost, low time consuming option.

 

[jneves]

Be cautious about the "cold" side too, because given an engine compartment fire, none of it is cold for long. Anything aluminum will be down to less than 10% of original strength in two, maybe two and a half minutes, all by conduction, no fire exposure. Cable fixation and the arm on the back of the door should be steel if we expect them to hold the door closed.

Thank you Dan! I have followed your threads on the topic and have made it a point to clean up both sides of the firewall. No more insulation on or near the firewall, confirm no AL and only SS was used for anything sealing the FWF and the cockpit.

You have done a great job reporting on this topic, thank you for your contributions.