FWIW:
Concerning the use of AC in back of the Gmc motor home. After being around
schools for the last 10 years in deep South Texas, some school busses in
this area have AC. I spend on average about 1hour of so a week going with
students to various locations In the community. It is hot most of the year
here and "I Love those Air Condition Busses"
After talking to the Transportation director on several occasions about this
very issues and drawing parallelism to school busses and our Motor homes. We
have concluded that if cost is not an issue then Ac unit running off of the
motor is great. And it works. In my observation Carrier has the best system.
They rely on massive (what ever is on the out side) unit with 12 V. Radiator
cooling fans. The units are placed on the bottom of the bus and air is
forced upward and 90 degrees out the side. On average is cost an extra $200
to $500 a year to keep these units running. Take a look at some school
busses for some idea. Most of these systems use 2 compressors. I consider
them just as noises as the roof air units.
In contrast we also have some busses with gensets and Roof airs on them.
They cost much less to operate. Around $100 to $200 a year.
Please understand thou these unit almost run year round. About 150 days a
year.
I to would love to be able not to run the genset on the highway.
Jack
1977 transmode
- -----Original Message-----
From: owner-gmcmotorhome
[mailto
wner-gmcmotorhome] On Behalf Of RickStapls
Sent: Friday, April 23, 1999 12:22 PM
To: gmcmotorhome
Subject: Re: GMC: A.C. Compressor (trivia)
> My system will use the A-6 as my sole compressor.
>
> On shorepower I will power it with a 2 hp 120 volt dual capacitor motor.
> Plans are to add a 2nd V belt sheave on a shaft extension screwed into
the
> 1/2" pipe threads on the front of the A-6 shaft.
Donald,
I like this idea, but my concern would be overspeeding the 120V motor
when
the 455 hits 4000 rpm with the AC on. I'd feel better if I could use dual
clutches or an overrunning clutch or sumthin'.
I'm enjoying this thread, and want to toss in a few ideas, FWIW:
1 What about supplying one (or even both) roof AC units with freon from
the A-6? Since they're already located in the "right" place (up high) to
suck out the hot air, and take up NO precious interior space, they might be
just the ticket. You'd have to replace the blower motor(s) with a 12V, or
feed it from an inverter, but otherwise it's just a matter of plumbing and
wiring. (Or so I think...?) Along this line, would it make any sense to
have the A-6 pump high-pressure freon to the roof AC(s), and use the roof
condenser(s) to expel the heat, keeping it out of the engine compartment?
Would this work?
2 OTOH, I too would like a lower, cleaner roofline (recalling squeezing
under a 9' 6" railroad bridge in Amherst, Mass, when last we visited my old
home area......). I too have been eyeing the oven as a possible location.
(I want a heater core in there as well.) There is space behind the built-in
wardrobe drawers where you might run a duct to pick up hot air off the
ceiling. Don't know if you could get past the drain vent stack, or if
there's room for a cold duct too, but maybe worth investigating.
3 I too have eyed the space over the refrigerator as a possible AC space,
but when I pulled my Norcold 462 ("...'tis neither hot, Norcold.") last
summer to convert it into a 463 (3-way), I discovered the space is pretty
limited up there. The curve of the roof brings it down close to the refer,
and I'd be leary of constricting the airflow through there. Maybe it's
possible.....
4. If you use a box fan in front of the radiator, remember they aren't very
weatherproof. Not only does it get road-splashed, but the dash AC
evaporator
drips its condensate on it (helps cool the condenser too). Stock GMC fan
probably consumes 10+ hp when hot and locked up. Don't mean to say it can't
be done, only it won't be easy.
5 One more location for a second (or third! Thanks for the idea,
netizens!)
evaporator is over the rear window (where GM put the optional fishing-rod
cabinet). You'd have to make sure it cleared the emergency exit ring on the
window, and plumbing and wiring would be long, but it's a little-used high
up
spot.
Just some brain-balls to bounce around....
Rick Staples
'75 Eleganza
Louisville, CO
Concerning the use of AC in back of the Gmc motor home. After being around
schools for the last 10 years in deep South Texas, some school busses in
this area have AC. I spend on average about 1hour of so a week going with
students to various locations In the community. It is hot most of the year
here and "I Love those Air Condition Busses"
After talking to the Transportation director on several occasions about this
very issues and drawing parallelism to school busses and our Motor homes. We
have concluded that if cost is not an issue then Ac unit running off of the
motor is great. And it works. In my observation Carrier has the best system.
They rely on massive (what ever is on the out side) unit with 12 V. Radiator
cooling fans. The units are placed on the bottom of the bus and air is
forced upward and 90 degrees out the side. On average is cost an extra $200
to $500 a year to keep these units running. Take a look at some school
busses for some idea. Most of these systems use 2 compressors. I consider
them just as noises as the roof air units.
In contrast we also have some busses with gensets and Roof airs on them.
They cost much less to operate. Around $100 to $200 a year.
Please understand thou these unit almost run year round. About 150 days a
year.
I to would love to be able not to run the genset on the highway.
Jack
1977 transmode
- -----Original Message-----
From: owner-gmcmotorhome
[mailto
wner-gmcmotorhome] On Behalf Of RickStaplsSent: Friday, April 23, 1999 12:22 PM
To: gmcmotorhome
Subject: Re: GMC: A.C. Compressor (trivia)
> My system will use the A-6 as my sole compressor.
>
> On shorepower I will power it with a 2 hp 120 volt dual capacitor motor.
> Plans are to add a 2nd V belt sheave on a shaft extension screwed into
the
> 1/2" pipe threads on the front of the A-6 shaft.
Donald,
I like this idea, but my concern would be overspeeding the 120V motor
when
the 455 hits 4000 rpm with the AC on. I'd feel better if I could use dual
clutches or an overrunning clutch or sumthin'.
I'm enjoying this thread, and want to toss in a few ideas, FWIW:
1 What about supplying one (or even both) roof AC units with freon from
the A-6? Since they're already located in the "right" place (up high) to
suck out the hot air, and take up NO precious interior space, they might be
just the ticket. You'd have to replace the blower motor(s) with a 12V, or
feed it from an inverter, but otherwise it's just a matter of plumbing and
wiring. (Or so I think...?) Along this line, would it make any sense to
have the A-6 pump high-pressure freon to the roof AC(s), and use the roof
condenser(s) to expel the heat, keeping it out of the engine compartment?
Would this work?
2 OTOH, I too would like a lower, cleaner roofline (recalling squeezing
under a 9' 6" railroad bridge in Amherst, Mass, when last we visited my old
home area......). I too have been eyeing the oven as a possible location.
(I want a heater core in there as well.) There is space behind the built-in
wardrobe drawers where you might run a duct to pick up hot air off the
ceiling. Don't know if you could get past the drain vent stack, or if
there's room for a cold duct too, but maybe worth investigating.
3 I too have eyed the space over the refrigerator as a possible AC space,
but when I pulled my Norcold 462 ("...'tis neither hot, Norcold.") last
summer to convert it into a 463 (3-way), I discovered the space is pretty
limited up there. The curve of the roof brings it down close to the refer,
and I'd be leary of constricting the airflow through there. Maybe it's
possible.....
4. If you use a box fan in front of the radiator, remember they aren't very
weatherproof. Not only does it get road-splashed, but the dash AC
evaporator
drips its condensate on it (helps cool the condenser too). Stock GMC fan
probably consumes 10+ hp when hot and locked up. Don't mean to say it can't
be done, only it won't be easy.
5 One more location for a second (or third! Thanks for the idea,
netizens!)
evaporator is over the rear window (where GM put the optional fishing-rod
cabinet). You'd have to make sure it cleared the emergency exit ring on the
window, and plumbing and wiring would be long, but it's a little-used high
up
spot.
Just some brain-balls to bounce around....
Rick Staples
'75 Eleganza
Louisville, CO
