Airflow for strong ultra 80 with smaller kw lamp

[Dennis Fung]

I got a pair of Ultra 80 lamp house for a new art house cinema, however it was too bright and the exhust fan requires 700 cfm for each.
I have to turn off the digital projector cool down first and power up two 35mm projector later. Not really nice for opearation.

Just wondering if I change the xeron lamp into 3 - 5 kw lamp power, is it possible to lower down the exhust air requirement for each lamphouse?
Or no matter how powerful for the lamp power, I should stay 700 cfm?

Thanks!

[Steve Guttag]

You can lower the exhaust...but...the air flow switch will likely not stay up. The Ultra-80 is presuming a larger lamp though we used them over the Super-80 in all installations, even for 3KW lamps. You might consider getting in-line fans for the film machines like the Fantech FG8XL, or whatever may be available where you are located with similar specifications. Then install dampers so you can close down what you are not using. So, if you are using digital, turn on the first film projector/lamp and open its damper...once the digital has cooled, close its damper and open the second film and turn it on. Alternately, get a variable speed exhaust that can be set to increase exhaust as more systems are on line.

[Harold Hallikainen]

I think a temperature controlled variable speed fan would be interesting.

[Steve Guttag]

Way over complicated Harold. Probably a two-speed fan would be sufficient (or two presets on an inverter drive. Go to high speed when film is running and normal speed if just digital. Normally, we just recommend two exhaust systems, sized appropriate for the equipment in use.

[Mark Gulbrandsen]

While 700 CFM may be ok with an Ultra 80 because of it's aux blower on top of the lamphouse., it was not nearly enough for a Super 80 running a 4kw lamp. On those, 1200 CFM gave much better 4kw lamp life.

[Gordon McLeod]

It is virtually impossible to draw 1200cfm of air through a 8" round duct

[Mark Gulbrandsen]

It is virtually impossible to draw 1200cfm of air through a 8" round duct

We usually used an FG10XL blower through 10 inch duct And, according to my air flow meter it was spot on.. The quickest way to crispy wiring in any Strong lamphouse is to use too little exhaust.

[Gordon McLeod]

The vent on super 80 is 8"and the size of the air inlet restricts what passes through the airflow maxs at around 800cf

[Steve Guttag]

We usually used an FG10XL blower through 10 inch duct And, according to my air flow meter it was spot on.. The quickest way to crispy wiring in any Strong lamphouse is to use too little exhaust.

And from the Fantech sheet:

Fantech.JPG

Looks like the FG10XL tops out at 589cfm and that is right at the inlet with no restrictions on the top. Most use the FG8XL which tops out at 502cfm...and as Gordon points out, the 10x8 reducer will put a restriction on the FG10XL so you won't get all 589.

1200cfm on a 4K lamp is absurd and would whistle like the dickins. All duct work would likely be popping and fussing at the immense pressures involved and would require stiffeners to avoid collapse.

About as much as I've gotten through an 8" (200mm) duct is about 800-900 cfm. Kinoton's fan was at about 800cfm on their 2-7K lamphouse. That was good up to 6KW, easily. I'd specify 900cfm open-end to allow for the HVAC not allowing for restrictions and to avoid pressurizing the stack.

For the Ultra-80, I think you need something like 700cfm to satisfy the air flow. You could modify that to allow a lower air and for 3KW, 500-600cfm should be sufficient (all are open-end measurements, not fully connected with sensors within the duct and wires on the outside.

[Mark Gulbrandsen]

A theater I serviced back in the 1980's had a big go around with Osram not making good on warranty claims because Osram claimed the lamps were run at too hiigh a temperature.. After some negotiation with them they actually sent out a field service guy to look things over, and he found insufficient air flow to be the cause. The exhaust system at that site was completely revamped to meet their requested spec which was 1200 cfm + / - 50 cfm. I also compared my air flow meter to the HVAC crew's that did the work and they were both very close. Now I may be wrong on the fan even being a Fantech at that location, was a long time ago. But the net 1200 CFM that was cooling them now fixed the issue. No premature lamp failures after that. In all my own installations I used either an FG-8XL, or FG-12XL blower because I got really tired of repairing WW Grainger blowers..

[Steve Guttag]

The problem with the Osram lamps, particularly in the '80s was the Osram lamps. Not the cooling, not the inrush current, not the shipping company. When the chain I worked for switched to Christie (Ushio) lamps, all of the problems evaporated. We did a shoot out of Osram, Christie, ORC and I think Conrad-Hanovia. All the same lamp in essentially the same equipment...Super Lume-X running 2KW. The Christie lamps just trounced the competition. Not only did they not have the issues but they held their brightness better and didn't darken like the rest. They covered their warranty hours and then some. We also didn't need the warranty claims like the others.

I did other Christie vs Osram shoot outs even decades later...NEVER did Osram beat Christie/Ushio.

[Mark Gulbrandsen]

No arguement at all that Ushio is the best lamp, but the exhaust upgrades did take care of the early failure of the 4kW Osram lamps. When I was running my.own.supply in Chicago, I sold Hanovia and ORC lamps and actually had very little trouble with both brands. Some one else in Chicago already had the Ushio dealership wrapped up.