If I had a dollar for every comment I’ve read over the years about the terrible/non-existent heaters in old air-cooled VWs, I’d be…a few thousand dollars richer. How odd; I managed to stay quite warm in mine, during the then-colder winters of Iowa in the “Little Ice Age” of the early ’70s.
But then I read the owner’s manual, apparently unlike all those cold former VW drivers:
There it is: crack open the vent window, for the very obvious reason that the essentially air-tight VW body will keep the warm air from being blown in by the engine’s cooling fan. It may sound counter-intuitive, but if you’re familiar with just how air-tight a VW is, it makes all the sense in the world.
It’s quite different in a water-cooled car, as the air in the car’s body (or fresh air) is circulated through the heater core, over and over. And the great majority of cars were anything but air-tight, although that’s largely irrelevant in this case.
There’s nothing intrinsically about air-cooled engines that should keep them from supplying plenty of heat to the car. Air cooled engines throw off heat just like water-cooled ones. It’s a bit simpler and probably a bit more efficient to tap the hot coolant for a heat source via a liquid-air hear exchanger (heater core) than to channel the cooling fan’s output into the body, either directly (prior to 1963) or via heat exchangers (1963-on “fresh air heat”). There’s several things that can go wrong to affect a VW’s heat output.
DougD, who sent me the scan from his ’63’s owner’s manual, also sent me this shot of two VW heat exchangers, the original (right) and an aftermarket one (left). Guess which one is going to be substantially more efficient in extracting the heat from the exhaust? Heat control cables can break, freeze, or become disconnected. The heat travels from the engine to the front via channels in the body’s sills. If they rust out, heat will of course leak out. And if any of the various ducts and/or engine tin (cooling shroud) is damaged, removed, or not connected properly, heating will be impaired negatively.
But if it’s all working, it works well. In the Vintage Review of a ’53 VW by Tom McCahill that we’ve posted here, McCahill extols the VDub’s heat during a major New England blizzard in his usual flowery prose: “The heater was giving us Palm Beach weather while all hell was cutting loose“.
And I just read another one (which I wasted 20 minutes finding again) that praised the VW’s heater.
VW did offer an optional gas-fired heater, which created an instantaneous blast of hot air. These were not uncommon in really cold locales, like parts of Canada and Scandinavia.
And yes, the center defroster outlet added in 1966 did help, augmenting the output of the original two corner outlets. The issue of the inside of the windshield frosting up from the passenger’s breath was a real one, on cold mornings, due to the proximity of the windshield to their faces.
And to placate freezing American VW drivers who didn’t read their owner’s manual, a fan was also added in 1968, and then a two-speed version in 1971 along with outlets behind the rear side windows. Cracking the vent windows was now no longer necessary.
VW was a pioneer in having standard heating at a time when heaters in water cooled cars was either optional or not even available. The first series of prototypes in 1938 (VW38) had no heating system, and had to use catalytic windshield heaters. Folks didn’t drive as much in the winter back then, and bundled up if they did. But the final series of prototypes of 1939 (VW39) used the otherwise wasted hot air of the cooling system, and channeled it into the body. It was something of a sensation at the time, to have such a low priced car with standard heating, another way in which the VW was vastly ahead of its time.