Where does all the heat go ??

Me CMC has the 'factory' heat box hook up on the tub. From there it goes somewhere and ends up at the outlet by your feet. In the process the air looses all the heat, put a blower on it and now I get faster cool air. I ran a hose forn the heater box to the inside of the car - will burn your finger, real hot. How can there be that big a heat sink in the 4' or so the air travels in the stock duct? Any creative ideas for rerouting air flow channels??
Tks Bill

Bill, on pan-based cars the standard heater channels are part of the VW pan itself. They may be leaking and/or insulating them may help. Even when a VW was new the heat/defrost was pretty marginal, even after they went to the "fresh air" system.

Also, make sure the heater box valves open and close properly (the ones operated from your cockpit heater on/off control), and check the connections from heater boxes to chassis heater channels.

George,

Just a correction. The heater channel on a VW was not on the pan. It was the section of the body under the doors which the pan bolted to.

Right you are about the heater channel, which means the replica builders do their own thing for heater channels.

I would check all my air connections. First, the heater boxes, then the tube that goes into the pan. I'm like you, if it is sealed up I can't understand how you are loosing all the heat??? It may take a little longer to warm up to you, but it should get there. It sounds like you are getting airflow. Maybe a thin insulation right where the channel goes. Now the tubing on the CMC is real guage metal, not the thinner metal that beetles had. However, these pans are about 12 shorter, so there you go? I'm in Texas, so a little heat goes a long way. In fact, my Speedsters don't cool down from August until February 8).

Thanks guys! Like you, I don't really understand it. Have good air flow our the exits in the interior. Thot adding a blower would up the velocity and give less time for heat transfer - probably one of the last times I'll bother to think. I'm still showing ~ a 30 deg. temp rise over ambient temp. 50 to 80 is ok but 10 to... well you get the idea. I may move the heat entrance around to the bulkhead by the rear of the door opening eliminating the heater channel, have lotsa heat from a hose from the heat box out dumped to pass. compartment. Could try to get it pass for carry on luggage and move it deep in the heart of TEXAS too and the heck w/ the heater.

Bill,
You didn't hurt anything with the new blower, as you are still adding the same amount of heat to the air as it passes the heat exchangers. You may even be picking up a bit more heat than before, if you are extracting more heat from the exhaust (due to your reduced temperature rise). However, comfort is also determined by perception- in the same way that a 70 deg home heated with a heat pump doesn't feel as warm as a 70 deg home heated with a gas or electric furnace. Discharge temp is important, and sometimes less air feels less "drafty". There isn't really anything wrong with a heating system using heat exchanged from the exhaust- but you can't transfer the heat again (back to the great outdoors) before you discharge the air into the cabin of your car. The solution to your problem is insulation. If it isn't practical to insulate your frame rails, connect your heat exchanger outlet tubes to a more insulating duct- maybe a piece of tubing with armaflex insulation. If you can keep from heating the frame of your car, you can heat the interior, and you'll be a lot happier.

Stan
Yup thought about that - real vs.preceived heat thing. Stuck my dark room thermometer in the heat duct outlet and thats where I came up with the 30 deg. rise. Didn't trust my hands evaluation. The metal in the ducts must be really heavy duty so maybe if you drove 50 mi or so it would eventually heat up. Don't know the temp from the hose I Mickey Moused into the pass. area, but it gets hot enough you sort involuntarily move your hand out of the way, prretty toasty. Looks like I either cut a hole in the existing dust work and insulate or figure an alternate route for heater ducts.

Bill, what blower kit did you install, and where inline did you put it? Im interested in doing the same thing. Eddie

Eddie
Got the blower at a VW show/swap meet. Think it's some varient used on VWs at some point in time. It's just a squirrel cage blower with two outlets. Mounted it on the 'frame rail' between the engine and passenger compartment and ran one outlet to the input on each heaterbox, not using engine cooling air at all. As a interesting (?) sidelight, there apparently is a high pressure area where the blower is mounted as I get air moving through the heaterbox and into the car with the car in motion and the blower shut off. Maybe my interior is sooo bad it just sucks, dunno, I just tighten bolts and wire wires.
Bill

Eddie, there are relatively small 12V in-line bilge blower fans for boats and I think some of them are even two-speed. Might work for boosting a replica Speedster heater system. My IM has the 3-speed fan and heat/defrost control all mounted under the dash.

Thanks for the info guys. Has anyone tried the heater booster kit made by Barneys Import Parts, that is advertised in Hot VWs? If so please report. Eddie

Bill,

It sounds like you have a wide open heater channel. You may need to slide some flex hose through the heater channel to the front of car. I suspect this may be hard to do. It may be something which can only be done with body off pan. With air flow when all heat is off and such loss of heat it just sounds like you are sending heat to the wind.

You could search the archieves for "Heater" or "Blower". We had several web site posts last year that had actual photos of booster kits. Also, the bilge pump web site George mentioned were listed. I remember surfing there and was impressed. They were reasonable and would mount right where the tubes enter the pan. Then you just shortened your flexible tubes from the heater boxes to the pan, putting them on the bilge pump inlets. It was a really slick setup and it had to add a volume of air.