Posted by Tom on April 9, 2006, 3:32 pm
I have a direct loop. Water is taken from my 75 gallon tank from the
bottom and returns from the collector at the top.
I live in Los Angeles away from the ocean, so I have typically lots of
sun and it's rare that we would have days in the 40's. Mid 50's to mid
60's is usually typical for the winter in the San Fernando Valley,
although we get many days in the 70's and 80's.
With the condensation problem, on a day when it reached almost 90
degrees and in full sun the Gobi was making 120 degree water with
absolutely no usage of hot water in the house, so no cold water was
entering the loop.
I guess what I would like to see optimally is a system that recovers
quickly. If 140 is going to be my ceiling then I would want to get back
to there ASAP.
Did it seem odd to you that the gobi has no seal between the glazing
frame and the collector. That's 28 linear feet of potential escape route
for heat, unless aluminum against aluminum held by sheet metal screws is
and effective seal. I emailed the manufacturer last night to ask them
about this but Heliodyne has never returned an email, not one, so I'm
not holding my breath.
Posted by SJC on April 9, 2006, 5:09 pm
I think that they purposely did not seal the glazing with neoprene =
because of the
expansion/contraction problem. They want to keep the rain out, but when =
inside goes up to 150F and expands they want it to go out.
By open loop, do you mean it is a drain down system that is connected =
water main, or? I can see in S Cal you would get 60-70F days this time =
and the delta temperature would be more like 60-70F. If you look at the =
you might get your tank from 120F to 140F in a day with no water used.
Depending on air temp at night, the tank could lose as much as 1 =
degree F per hour, so for
18 hours it might lose 18 degrees F. These are just rough numbers, but =
you can see that they would
be necessary to calculate one 4 x 10 collector and a 75 gallon tank that =
uses maybe half that
per day and the city/well water is let's say 60F.
Heliodyne should be able to tell you if one 4 x 10 collector is =
enough for a 75 gallon tank.
I have always throught one collector might be adequate for a 40 gallon =
tank. But that depends
on feed water temperature, air temperature during the day and night, =
water usage, sun angle,
latitude, positioning and other factors.