Heater discovery

[Billm]

For the round trip from Seattle to Elkhart Lake and back I took the heater core out of the heater box to allow for full, unobstructed airflow into the car. I felt that without the core the air would flow so freely that it would be cool. Wrong!
About half way back home I did an experiment and insulated the INSIDE of the heater box front and back panels(with two layers of paper towel and a covering of duct tape).
It WORKED very well. the air was not cold but far cooler than the blast-furnace air that is normally there. I think that if I further insulate the perimeter frame of the heater box then the air coming in will be down to very close to the outside air temperature.
Guess that the black steel of the heater box conducts heat pretty well.
BillM

 

[vagt6]

Good idea, Bill. Also probably a good thing to use non-combustible material for your insulation.

You don't want smoke comin' out of your heater!

 

[Trevor Jessie]

Hmmm.... maybe a market for a "cool air kit" complete with insulated box and hose?

 

[RickB]

I'll bet ducting insulation would work great inside the box and they make insulated round ducts for AC and such - the trick would be getting the right size.

Or use that silver colored bubble wrap insulation stuff and somehow get it to line the inside a 4 inch hose.

 

[HAN8L1965]

Why not line the inside with dynamat or a generic knock off.

Mark

 

[KSIS]

Use the metalic tape for heating duct. that stuff is very hand. Just used it to reline the reflectors of my rear lights.

 

[Billm]

The only problem with the metallic tape is that its insulation properties are not too good- something like Dynamat probably has promise but whatever is used it needs to be very thin (to clear the heater core) but still have an insulation factor as high as possible.

 

[middie]

Wait a minute . . . wait a minute . . . are telling me that the heater blows hot air even if it isn't on????? I haven't driven my Spitfidget yet and now I'm worried that I'm going to cook.

In Australia it is mostly quite warm, except in the depths of winter when I probably won't be driving. So, am I going to have hot air blowing on me that is even hotter than the air outside????

Now I'm seriously considering not putting the core in the heater box at all. Am I on the wrong track or something???

Wazza

 

[vagt6]

Wazza, if your heater control valve is turned off (thus stopping the flow of heated water to the heater core) your heater shouldn't blow hot air. The air duct for the heater picks up air from the front of the car so the air coming out of your heater ducts shouldn't be significantly hotter than the ambient air temperature.

At least that's how it works on my MK III Midget. Even in traffic in hot weather, I don't note any hot air coming out.

I say keep the heater core, just in case you want to drive on a cool evening.

 

[Billm]

The air coming in when the heater core is turned off is fine and not too much hotter than the outside air for about the first 20 miles or so of a drive, after that the underhood temperatures (guessing about 160 degrees or so) start to soak through the heaterbox (it is just one sheet of black steel, no insulation) and heat up until you will think that it is a blast furnace on a hot day with a long drive (like 500 miles across central Montanna in the summer last week).
The insulation really does help on longer drives in hot weather. On the MG Experience someone recently made an adapter from a baking pan to replace the heater box and just get the air into the footwells with far less metal, sounds like that works too but I want to keep my heater in place for the near constant winters that we have here in Seattle (like now).
BillM

 

[BugeyeNJ58]

On mt BE 1275 I have the heater removed. I've got a rubber tube running from the heater valve up to the radiator. I keep the valve open as the flowing water seems to help keep the water temperature down.

Does anyone have any sort of "Dual Flow" Setup? If I put the heater/core back into the care, I want to be able to either run the water back to the radiator, or run it through the heater box. Anyone running anything like that?

 

[RickB]

Awww Bill, it's supposed to warm up today - it should reach 72!!
I know that's about 50 degrees lower than what it was in our cars coming across the midwest, but hey it's not winter.
Though, I may turn on the seat warmer if I go out in the Midget today...

I think the Frost King duct insulation would work perfectly inside the heater box. It's only about 1/8 inch thick and it's very good insulation (for being so thin).

 

[nomad]

BugeyeNJ: The subject came up a while ago but don't know what became of it. I'm sure that you could source a 3 way valve from some plumbing supplier. To feed the bypass back to the rad you could use a siamesed bottom hose to replace the top hose or you could drill and tap your water outlet for a fitting.

Kurt.

 

[BugeyeNJ58]

Thanks Kurt. Don't mean to hijack this thread, but I found this on the forum that addresses what I was asking. https://www.britishcarforum.com/bcforum/ubbthreads.php/topics/735073/1

 

[middie]

Thanks for clearing up the heater confusion for me. So it looks like it is a good idea to put some insulation on the inside walls of the heater box to stop it transferring the engine bay heat.

I was only thinking of the heater duct bringing in air, didn't even think of the heat being generated around the engine area. Goes to show that you only have to ask the "gurus" on the forum to get a great answer.

Wazza

 

[Billm]

Interesting to see what the factory racing cars used to keep the driver's feet cooler-
Look about 3/4 of the way down and see that the vent hose bypasses the heater area and dumps straight on the driver's feet.

https://fantasyjunction.com/cars/1104-Aus...Racing%20Engine

BillM

 

[RickB]

So is there just a hole cut in the top of the footwell then?
Think they put a screen in the front of the hose to keep small furry creatures out? I would.
I like this design, it's simple and you could just make a blanking plate and cover it for the winter re-routing your intake hose to the heater.
Summer time just do the the opposite.

I am a big fan, and would like to subscribe to your newsletter.