REFLECTOR: Cabin Heating

Thu, 29 Jan 2004 20:50:58 -0500

Thanks for the info Chuck.  I'll give it a try.

Jack
----- Original Message -----
From: "Chuck Jensen" <cjensen@dts9000.com>
To: <reflector@tvbf.org>
Sent: Thursday, January 29, 2004 8:26 AM
Subject: RE: REFLECTOR: Cabin Heating

> The strip of duct tape will certainly slow down the total air flow some,
but
> it may not improve heat exchange much.  Where the duct tape strip sets on
> the oil cooler face, the fins behind the tape have minimal opportunity to
> add warmth to the air.  At the same time, the velocity of the air on both
> sides of the tape may well be higher, thus negating its ability to grab
heat
> on it's way by.
>
> A better solution may be to get a cloth bag filter (pool supply places
have
> them; they are used all the time for water processing) and cut rectangular
> patches the approx. size of the front side of the cooler.  Use white duct
> tape to secure the edges (but don't intrude onto the front of the cooler
> much if you can help it).  The white duct tape and white bag filter will
> virtually disappear.  Put two layers on for your first test.  That will
> markedly slow down the air flow while allowing nominally 100% of the
cooler
> to be exposed for better heat exchange.
>
> You can further adjust engine oil/cabin temp by adding/removing layers.
For
> a day in the 40-50F you may remove all but the first layer, for <0C day,
you
> might add a third or fourth layer.  It's manual but it looks good and
works
> will.
>
> Chuck
>
> -----Original Message-----
> From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
> Behalf Of jack davis
> Sent: Wednesday, January 28, 2004 10:08 PM
> To: reflector@tvbf.org
> Subject: Re: REFLECTOR: Cabin Heating
>
>
> I have done exactly this (i.e., fabricated a flapper valve that directs
all
> incoming air into the cabin).  You get very good heat when the engine is
> running at 65% power or above and when the outside temperatures are above
> about 15 degrees F.  Below that temperature, it is a bit cool in the
cabin.
> I also place a strip of duct tape across the front side of the oil cooler
> (as Duane Swing suggests).
>
> Jack
> ----- Original Message -----
> From: "Jim Sower" <canarder@frontiernet.net>
> To: <reflector@tvbf.org>
> Sent: Wednesday, January 28, 2004 4:01 PM
> Subject: Re: REFLECTOR: Cabin Heating
>
>
> > It sounds like most of what we need is already in place.  My 173FG has
the
> front oil
> > cooler in a plenum.  The input to the plenum is the NACA in the nose,
and
> it exhausts
> > out the bottom of the plenum.  I have a 2" duct out the back of the
plenum
> going to
> > the cabin foot warmers (could be larger and go to more places).  As it
> stands now,
> > only the (tiny bit of) exhaust from the oil cooler that doesn't go
> overboard goes into
> > the heat system.  I aim going to make a flapper valve that can cover
> either the outlet
> > to the cabin completely or the overboard opening completely or anything
in
> between.
> >
> > If it's really cold, I'll block the overboard vent and the only air that
> passes
> > through the oil cooler will be whatever the outlet to the cabin will
> permit.  Air flow
> > will be much reduced and therefore much hotter.  If I don't need that
much
> heat, I can
> > crack the overboard vent which will increase flow through the cooler but
> reduce flow
> > into the cabin (the rest going over the side).  I can keep venting the
> overboard vent
> > more and more until I have the cabin vent blocked and all the air the
> cooler will pass
> > going over the side.  One flapper valve, a plenum that's already there,
no
> additional
> > oil coolers.  I may have to make a new plenum so the flapper will fit
> between the
> > cooler and cabin outlet bulkhead and be big enough to cover the
overboard
> vent, but
> > that's not rocket science.
> >
> > Limiting air flow to the hot air I need should make for enough delta-T
to
> heat the
> > cabin, and increasing air flow as my heating requirements go down will
> tend to match
> > increased oil cooling requirements.
> >
> > Just a theory ... Jim S.
> >
> > Dave Black wrote:
> >
> > > Scott,
> > >
> > > > I think if you had the nose oil radiator and an inside one for cabin
> > > > heating you could easily run them in series, much easier plumbing.
> > > >
> > > > Then close off the cabin heat outlets on the oil cooler duct.  If
your
> oil
> > > > is too cool just close the flap(that used to direct the air into the
> cabin)
> > > > a bit thus reducing the flow through the radiator and raising the
oil
> > > > temps, good for the engine and for the passengers too.
> > >
> > > You may be on to something! It would be stone simple plumbing. And I
> believe
> > > it would be a huge improvement over the standard nose cooler only
> > > installation.
> > >
> > > I see two drawbacks:
> > >
> > > 1) The total length of the oil line. The longer the line, the more
> 'congealed
> > > oil plug' effect you have in cold weather. But now that I think of it,
> with
> > > this system, there'd be absolutely no need to leave the original
cooler
> in the
> > > nose. Rather, it should be relocated to the engine compartment. Hence
> the
> > > total plumbing could be MUCH shorter than the standard system.
> > >
> > > 2) The cabin heater would always be hot, even in summer. However I'm
> certain
> > > that with some clever design, most of the unwanted heat from the cabin
> heater
> > > during the summer can be contained, blocked from entering the cabin,
or
> ported
> > > overboard. Heck, if the unwanted heat can be eliminated efficiently,
the
> cabin
> > > heater could even be used during summer as an auxiliary oil cooler.
> There are
> > > certainly times when that would be a good thing.
> > >
> > > All-in-all, I believe two coolers in series with no valves is a big
> > > improvement over the standard system. Certainly it'd be a very simple
to
> > > plumb, and cabin temperature control becomes a matter of controlling a
> blower
> > > motor and flapper(s).
> > >
> > > I guess a flapper valve located in the cabin floor could direct hot
air
> either
> > > back into the cabin or overboard. It needs to work quite effectively
to
> keep
> > > the cabin from getting hot in summer. But I'll bet it could be done.
On
> the
> > > other hand, putting a bypass valve around the cabin heater would keep
> the heat
> > > out too.
> > >
> > > Hmmm...
> > >
> > > Dave Black
> > > Shortwing RG
> >
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