Cooling all 23 feet with the Dash Air - can it be done? Dual System?

[dave silva]

The consensus seems to be that it's very hard to get the dash air to properly cool the entire coach when it's really hot.

I live in North Carolina so it will be REALLY HOT in about 8 weeks and it will stay that way for four months.

So, which is the biggest and best Sanden compressor i can install?

I already have an aux dash unit to blow the cold out a little better. What else?

I'm thinking a rear AC unit from a conversion van.

Apparently the system makes enough BTUs. The problem is distributing the cold air.

Somebody must have worked through this.

Long range plan is to replace the generator and roof air with batteries and a minisplit but in the interim the coach would be more useful if i could
make it comfortable in August.
--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

 

[Keith V]

II put a 2nd system in under the couch that runs off the enine AC, worked great but not it appears the compressor failed
________________________________
From: dave silva
Sent: Tuesday, March 15, 2022 1:25 PM
To: gmclist
Subject: [GMCnet] Cooling all 23 feet with the Dash Air - can it be done? Dual System?

The consensus seems to be that it's very hard to get the dash air to properly cool the entire coach when it's really hot.

I live in North Carolina so it will be REALLY HOT in about 8 weeks and it will stay that way for four months.

So, which is the biggest and best Sanden compressor i can install?

I already have an aux dash unit to blow the cold out a little better. What else?

I'm thinking a rear AC unit from a conversion van.

Apparently the system makes enough BTUs. The problem is distributing the cold air.

Somebody must have worked through this.

Long range plan is to replace the generator and roof air with batteries and a minisplit but in the interim the coach would be more useful if i could
make it comfortable in August.
--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

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[jim kanomata1]

Go to our web site and see the correct unit and mountings and hoses,

> II put a 2nd system in under the couch that runs off the enine AC, worked
> great but not it appears the compressor failed
> ________________________________
> From: dave silva
> Sent: Tuesday, March 15, 2022 1:25 PM
> To: gmclist
> Subject: [GMCnet] Cooling all 23 feet with the Dash Air - can it be done?
> Dual System?
>
> The consensus seems to be that it's very hard to get the dash air to
> properly cool the entire coach when it's really hot.
>
> I live in North Carolina so it will be REALLY HOT in about 8 weeks and it
> will stay that way for four months.
>
> So, which is the biggest and best Sanden compressor i can install?
>
> I already have an aux dash unit to blow the cold out a little better.
> What else?
>
> I'm thinking a rear AC unit from a conversion van.
>
>
> Apparently the system makes enough BTUs. The problem is distributing the
> cold air.
>
> Somebody must have worked through this.
>
>
> Long range plan is to replace the generator and roof air with batteries
> and a minisplit but in the interim the coach would be more useful if i could
> make it comfortable in August.
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

--
Jim Kanomata ASE
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[tyler]

Raleighite here - done Florida a few times and beach plenty for heat experiments.

My list of thoughts in no particular order:

- expectations. You already know it will be hot. another Raleighite I know simply does not camp in the summer. not a show stopper for me
- start with coach cool. I load up with camper in my known shade if daytime departure
- plan around heat. the 100+ degree days headed west into the sun that generates stories like one I have should simply have been avoided. but
schedules, family, etc said that was the day to go. it wasn't.
- 23 seems better than my 26 in theory, less to cool
- I run roof air as complement. that extra generator gas is cheaper than any mods I might ever do to the dash air. if your house system is not
working, I would put money there first
- pull the curtain behind the front seats to isolate front cabin if dash is basically good. this works well if not driving into the sun
- I pull my window shades on the sunny sides. that helps a good bit. some coaches don't have this, but it is simple to improvise if not
- I have a 6 inch 12 volt fan on the floor (like a trucker dash fan) between the front seats that blows at my legs. most of my dash air shoots
straight out of the center and the little extra fan actually gets it to me
- I am thinking about adding directional, in line, booster fans to make the above extra fan semi-permanent. like a bilge blower that I could aim right
from that center vent.
- my coach exterior is white
- if coach is keeping up with just dash air while driving, when i stop I will park awning side to the sun open it and run generator and roof air. dash
can't recover from the heat soak, so sometimes 20 minutes of gen will prevent a few hours of gen
- put a small silver windshield sunshade strategically if sun hitting driver side. of course keep visibility where you need it
- drive slower when you go under an overpass to maximize highway shade (ha, .1 seconds of relief)
- take precautions against vapor lock, simplest usually is an auxillary in line pump near the gas tanks. what is hotter than riding with a struggling
dash ac? sitting outside a non running coach on that same day

--
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC

 

[john r. lebetski]

I’m fortunate to have a 77. I can keep the living area comfortable with exception of rear lounge with dash air. I run it on NORMAL so 100% fresh air
is bring brought in and the 65 MPH ram air effect gives more flow than REC. This creates a slight positive pressure in the coach so any leaks are not
allowing hot humid air in. Even in the rear lounge the humidity is removed. When in REC you get more of a reversion loop up front. Usually use fan
speed 3 which with ram effect gives about same flow as Hi and REC on the highway. Only in extreme humidity does REC help by reducing latent heat.
When driving into sun mid day in the desert, yes the roof air may be needed from 2-5 PM only to overcome the sun load. Still have R12 in dash.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[dave silva]

More research and I am pretty convinced this is totally doable with a second evaporator in the rear.

THere is an off the shelf unit for van conversions for around $400 but i think something from a Suburban would be doable.

My coach will be used more for traveling than camping. Like a bog car- i don't want the generator and the roof air running and drowning out my
rolling history lectures to my kids.

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

 

[ken & dennis 2013]

I haven't seen it mentioned in this thread: R12 cools better than R134a;
and, Duracool (or equivalent hydrocarbon) cools better than either.

Ken H.

> More research and I am pretty convinced this is totally doable with a
> second evaporator in the rear.
>
> THere is an off the shelf unit for van conversions for around $400 but i
> think something from a Suburban would be doable.
>
>
> My coach will be used more for traveling than camping. Like a bog car- i
> don't want the generator and the roof air running and drowning out my
> rolling history lectures to my kids.
>
>
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

 

[dave silva]

> I haven't seen it mentioned in this thread: R12 cools better than R134a;
> and, Duracool (or equivalent hydrocarbon) cools better than either.

Yeah, that's a given. My system was converted to 134 by the Coop ('cuz they have to) but I'll put in duracool.

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.