RE: Water vs. Glycol Heater Performance

["R. Cummings" <cumm@flash.net>]

At 07:29 PM 1/4/99 -0800, you wrote:
>Now how about Siera coolant?
>Avi
>
>-----Original Message-----
>From:	owner-quattro@coimbra.ans.net [mailto:owner-quattro@coimbra.ans.net]
>On Behalf Of R. Cummings
>Sent:	Monday, January 04, 1999 9:59 AM
>To:	quattro@coimbra.ans.net
>Subject:	Water vs. Glycol Heater Performance
>
>Just to give you an idea of the difference in performance between 50/50
>glycol/water and plain water, assume 200 cfm of air at 0f and 3 gpm coolant
>at 180f (not a bad assumption going down the road). A typical heater core
>with a face area of 52 sq. inches will deliver 32,800 btu/hr with water and
>31,600 with 50/50 glycol/water. The discharge temperature of the air would
>be 151.5f with water and 146.1f with 50/50.
>
>Bob Cummings 87 Coupe GT
>
Good question Avi. A number of our customers are switching to propylene
glycol. Our calorimeter heater core testing still uses ethylene glycol so I
have no definitive numbers. I will say that some heavy duty vehicle testing
done on Baker grade last summer did not show degredation with propylene glycol.

My point really was that if someone is having heating problems, it is very
unlikely due to the composition of the coolant. It is much more likely to be
reduction of coolant flow due to crud in the heater core, water valve  not
fully open or collapsed heater hose.

Bob Cummings 87 Coupe GT