Film-Tech Forum ARCHIVE: Modifying Cooling on a Super Hightlight

This is topic Modifying Cooling on a Super Hightlight in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jeremy Weigel (Member # 4208) on 04-07-2007, 03:07 PM:

Has anyone tried modifying the forced air lamp cooling system on a Super Highlight console? It just seems to me that the single air spout at the front of the bulb doesn't provide enough air flow over the bulb.

Posted by Mark Gulbrandsen (Member # 72) on 04-08-2007, 09:20 AM:

You didn't say if it is a Highlite or Highlite 2, the 2 also has a front mounted blower below the schnood. If your exhaust was properly set up the normal internal cooling is usually adaquate for up to a 3kw lamp. The exhaust should be 900 plus cfm for a 2kw and 1500 plus for a 3-4 kw. These are minimum specs I reccomend. If there is very little air comming from the internal exhaust then check the small squirrel cage blower to see if the wheel vanes are clogged with dust, this happens and is common. Disnmantle an clean at least once a year, more often if you're in dusty conditions. also oil the motor while you're at it. A few drops of 30 weight non-detergent in each hole is good.

Mark

Posted by Jeremy Weigel (Member # 4208) on 04-08-2007, 05:08 PM:

Hi Mark,

Its a Super Highlight (1988). I was looking to modify the cooling to something like how Strong has them now with the whole back end of the reflector boxed in with the high velocity blower(s) to push air from back to front over the bulb. I am also looking into mounting higher velocity updraft blowers aswell.

Posted by Mark Gulbrandsen (Member # 72) on 04-08-2007, 05:22 PM:

Could be done but it would cost$$. The more important aspect is thestack blower. That alone will increase lamp life drastically when its adaquate.

Mark

Posted by Jeremy Weigel (Member # 4208) on 04-08-2007, 07:23 PM:

"Stack blower"? Are you refering to the updraft blower on the roof?

Posted by Mark Gulbrandsen (Member # 72) on 04-08-2007, 08:43 PM:

Yes...

Posted by Jeremy Weigel (Member # 4208) on 04-08-2007, 08:46 PM:

Gotchya. [Big Grin]

Posted by Jeremy Weigel (Member # 4208) on 05-14-2007, 03:31 PM:

quote: Mark Gulbrandsen
The exhaust should be 900 plus cfm for a 2kw and 1500 plus for a 3-4 kw.

Hey Mark,

What size of air duct are you using to get 900+ cfm. My Super Hghlights (1988) have a 6" exhaust with flex transitioned to an 8" metal tube up to the mushroom blower. I had my HVAC tech take a look at the setup and he said it would very unlikely to move 900cfm (approx. 2 tons) through this size duct. He recommended transitioning from the 6" directly to to at least a 10" duct all the way up.

Posted by Gordon McLeod (Member # 33) on 05-15-2007, 08:30 AM:

Every elbow foot of pipe piece of flex introduces static pressure on the system loading the fan and as such reducing total CFM
It is virtualy impossible to move 900 CFm through a round 6" opening

Posted by Mark Gulbrandsen (Member # 72) on 05-15-2007, 04:56 PM:

We always spec. in 8" or 10" duct depending on how long the run is and the lamphouse wattage. We prefer the blowers mounted inside because outside maintainance is ONLY NEEDED in the winter when its blowing 60mph.

Mark

Posted by Louis Bornwasser (Member # 3063) on 05-15-2007, 07:05 PM:

Yes, indeed. My theatres once had pitched roofs and outside exhausts. We learned quickly that INSIDE blowers are best. A pitched roof with 1/2 inch of ice is no thrill when you have to tie down the extension ladders that allow you up-the roof. (Note that failures occur ONLY in cold weather.) Louis

Posted by Jeremy Weigel (Member # 4208) on 05-15-2007, 11:36 PM:

What kind of inside blower do you use?

Posted by Mark Gulbrandsen (Member # 72) on 05-16-2007, 07:09 AM:

Grainger 7C038 for up to 2kw... sized up with similar series blowers for up to 4kw and over that wattage the radial series bowers produce more air movement but are quite expensive. If you get just the 7C038 blower without motor Emerson makes a ball bearing motor that fits so you don't have to use the crappy Chineese bushing style motor Grainger supplies. The Chineese motor Grainger sells runs VERY hot! The Emerson makes this into a non-maintainance issue.

Mark

Posted by John Walsh (Member # 168) on 05-16-2007, 12:48 PM:

I was talking to an HVAC guy about xenon exhaust in a larger multiplex. He suggested that it might be better to design the system such that, say, half of the exhausts where ducted together and install a closet-sized air handler large enough. For some redundancy, half would be on one system, half on the other. When the cost of labor to frame out each hole in the roof, a buy and wire separate blowers for each projector, reduced maintaince etc. was added up, the idea did make some sense.

Posted by Richard Fowler (Member # 893) on 05-16-2007, 01:05 PM:

I did the return air closet idea on a multiplex upgrade in an old structure. All the air handlers for the auditoriums where located on the projection floor so building extra exhaust closets for the lamphouses where cost effective. Dampers where used to balance the system and has been trouble free in the past 22 years with excellent bulb life.
Every new or used Highlight we worked on where modified to eight inch prior to install. Older units with no reflector air chamber we would upgrade the wimpy muffin fan in the sheet metal support; end result better bulb life and less reflector pealing. We also had a $2.50 fix for the focus problem on the older units. [Wink]

Posted by Mark Gulbrandsen (Member # 72) on 05-16-2007, 01:29 PM:

We've also done cost comparisons over several jobs in past years but the thing about having even two central systems for say a 12 plex is that if one goes down on a Friday night you loose half the shows in the place till an HVAC guy can get there. Have done it both ways and cooling either way is good but over the years I still find myself going back to blowers mounted inside and for each booth for better insurance. The cost savings is nill if one whole side of the place goes down on a weekend.

Mark

Posted by Jeremy Weigel (Member # 4208) on 05-16-2007, 02:09 PM:

quote: Richard Fowler
We also had a $2.50 fix for the focus problem on the older units.

Please share. Have an idea of my own, but haven't tried it yet. It is quite anoying since the vertical and focus controls interact with that single pin holding the anode mount.

Posted by System Notices (Member # 2357) on 04-26-2010, 01:07 AM:

It has been 1075 days since the last post.

Posted by Jeremy Weigel (Member # 4208) on 04-26-2010, 01:07 AM:

Well, I finally got around to cutting the original 6" exhaust to an 8" opening using a jigsaw to do the cutting.

The back of the opening was kept in place while shifting the opening towards the front of the console and keeping it centered left and right.

I picked up the 8" collars (removed the adhesive foam seal that would have been exposed to the lamp) from Home Depot and ordered the 8"x8' semi-rigid aluminum flex ducting from Ace Hardware Outlet. Total cost of materials was about $150 and roughly 1.5hrs labor/console. I taped up plastic to the underside of the opening to catch the shavings/scraps and covered the projector head as well.

Pulling an average 850cfm now and the top of the console is considerably cooler to the touch. I have 4 of these consoles still in use with one now pulling just over 900cfm, but it has only about a 3ft run from the roof to the top of the projector.

Here are some pics of the first console I modified.

Posted by Jeremy Weigel (Member # 4208) on 04-27-2010, 09:37 PM:

Forgot to mention that I also boosted the internal air flow as well by stacking 2 of the fans together. It was a bit tricky to do, but worth it.

Posted by Richard Fowler (Member # 893) on 04-28-2010, 05:53 PM:

Stacking muffin fans works....we used to replace it with a small plenum box with a squirrel cage fan with much greater CFM....no more bulb or reflector peeling problems. Our $2.50 fix on the focus shaft was a shaft collar and leaf pressure springs....

Posted by Jeremy Weigel (Member # 4208) on 04-28-2010, 11:04 PM:

Hey Richard,

You wouldn't happen to be able to get pics of that focus fix?