Re: Howard's 47 Custom project
Posted by HH56 On 2013/8/28 11:44:59
Gator, thanks for the encouragement. As mentioned, this whole AC idea running ducts overhead in the 47 is all still a big maybe. Am not liking the idea of making holes in the headliner but haven't come up with an alternative either -- yet.
In thinking about how the ducts might work, I have done some very unscientific measurements which you might find interesting. Ordinary DVM with 20 amp capacity -- but not a precision unit -- and a cheapo anemometer using the meters per second scale held centered in air flow about 6" from louver. Power was supplied by a 50 amp battery charger for convenience.
The test "mule" was a gutted hangon unit I had on hand made by Nostalgic Air. It is a typical modern 12v dual shaft blower with a shunt type motor. High, Medium and Low fixed speeds. I did the measurements at 6v and 12v. The unit ran OK at 6v and didn't see any sign of unhappiness or overheated motor -- but it wasn't on for more than 5 minutes at any one time either. Since it has four 2 1/2" inch outlets, had to get creative for testing. Will admit right off there is a lot of inefficiency in the duct connections and testing method so the air measurements are more a comparison, not a firm value.
Here are some numbers using the dual 1" ducts with a louver on one side only. The other two are connected and air is free flowing. All 4 ducts are 12 1/2 foot.
6v Low = 2.8A Air flow 2 m/s --- 12v Low = 3.7A and 3.1 m/s
6v Med = 3.6A Air Flow 2.7 m/s --- 12v Med = 4.9A and 3.5 m/s
6v High = 4.9A Air Flow 3.1 m/s --- 12v High = 6.8A and 5.8 m/s
For comparison, air flow at both voltages with the normal 2 1/2" AC duct supplied for use with the unit and the same dual 1" ducts as was present in first tests still connected and free flowing. The large duct is about 5' shorter than the dual 1" ducts.
Low 5.4 and 6 m/s
Med 6.1 and 9.7 m/s
High 7.7 and 11.4 m/s
My conclusion is dual 1" ducts would provide a gentle air flow at the front and maybe equivalent of a single 1 3/4 inch. I would not want to try and cool the whole car with just those.
Attach file:
(29.79 KB)
(36.00 KB)
(35.64 KB)
(26.71 KB)
In thinking about how the ducts might work, I have done some very unscientific measurements which you might find interesting. Ordinary DVM with 20 amp capacity -- but not a precision unit -- and a cheapo anemometer using the meters per second scale held centered in air flow about 6" from louver. Power was supplied by a 50 amp battery charger for convenience.
The test "mule" was a gutted hangon unit I had on hand made by Nostalgic Air. It is a typical modern 12v dual shaft blower with a shunt type motor. High, Medium and Low fixed speeds. I did the measurements at 6v and 12v. The unit ran OK at 6v and didn't see any sign of unhappiness or overheated motor -- but it wasn't on for more than 5 minutes at any one time either. Since it has four 2 1/2" inch outlets, had to get creative for testing. Will admit right off there is a lot of inefficiency in the duct connections and testing method so the air measurements are more a comparison, not a firm value.
Here are some numbers using the dual 1" ducts with a louver on one side only. The other two are connected and air is free flowing. All 4 ducts are 12 1/2 foot.
6v Low = 2.8A Air flow 2 m/s --- 12v Low = 3.7A and 3.1 m/s
6v Med = 3.6A Air Flow 2.7 m/s --- 12v Med = 4.9A and 3.5 m/s
6v High = 4.9A Air Flow 3.1 m/s --- 12v High = 6.8A and 5.8 m/s
For comparison, air flow at both voltages with the normal 2 1/2" AC duct supplied for use with the unit and the same dual 1" ducts as was present in first tests still connected and free flowing. The large duct is about 5' shorter than the dual 1" ducts.
Low 5.4 and 6 m/s
Med 6.1 and 9.7 m/s
High 7.7 and 11.4 m/s
My conclusion is dual 1" ducts would provide a gentle air flow at the front and maybe equivalent of a single 1 3/4 inch. I would not want to try and cool the whole car with just those.
Attach file:
(29.79 KB)
(36.00 KB)
(35.64 KB)
(26.71 KB)
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=130306