Coach heaters and A/C

[George F. VerDuin]

Greetings to the two groups I watch.

A few hours ago I posted a speculative solution based on a personal problem.
It began a thought process that brings me to asking opinions...

I'm a newbie to my 1995 BMC-37 late last summer. I've spent the time
since purchase going over performance measurement and reading in the
20lbs of manuals and other paperwork that came with the coach. Throw in
some "major" maintenance items by the pro's. We are about "there" in
considering ourselves to be happy RVers in our Bird.

Focusing on the dash heating/cooling feature driven by the engine, the
equipment came to us in poorly performing condition [not so much as to
dissuade us from purchase], without owners manual, maintenance
procedure, or standard measurements of good-performance. By inspection,
the dash air handler seemed to be as supplied by Bluebird.

By disassembly we discovered a 90% reduction in air flow by "dirt" that
could not pass thru the evaporator core. We also found a clean heater
core largely because the hot/cold damper always operated in the "cool"
position and restricted the flow thru the heater core by maybe 95%. The
screens installed at both the outdoor and indoor air passages was fine
enough to stop a seagull but certainly not a mosquito nor cockroach.
There are no filters and access to the two cores for cleaning is only by
taking the unit apart.

I say all this in belief that our Bird is state of the art for 1995.
This is not a complaint and by reputation I expect others share our
experience. I do wonder however if we are missing an after market
opportunity.

If many of us experience the same problem I just went thru, then one
preventive solution is to find an after market filter unit that can be
easily cleaned or replaced periodically. I'm not much in favor of
tearing the unit down again because it is labor intensive and too easy
to cause other damage. Yes -- it may have taken 16 years to reach this
condition, but consider the previous years of "marginal" performance
while it is working up to it's really bad state.

I'm delighted to find this group with a focus near the coach I own. I
also recognize we all have a different personal tolerance for "marginal
performance" and threshold when we "initiate repair". I really doubt
that this is a 1995 BMC only type issue.

I don't want to cause folks to tear their air handler apart. I do want
to find out if there are known sources for rectifying manufacturer
oversight or after market improvements. I do like my Bird, but it is
now 2012 and many things have had opportunity for discovery and
improvement since 1995 that I'd like access to.

Any thoughts?
George