Recent content by LSA

Used this product in all of our grease exhaust design: "Zero Clearance to combustibles can be achieved with 1.5" of FireMaster FastWrap+ per the UL 1978 Test which is accepted by NFPA96 and the IMC 2003 or earlier." Great product and approved for use in Los Angeles.

R = 0.032 with 3 years experience after graduation R = 0.25 with 7 years experience since being in the HVAC industry

Let me take a stab at answering this. The ductulator provides friction loss per 100ft. At 2000CFM in a 14"DIA duct the friction is 0.32" per 100ft of duct. If your AC equipment is 100ft away and therefore you have 100FT of duct, your duct pressure loss is 0.32" A more simplified approach is...

Air change rate per hour (ACH) is determined by the Amount of Air exhausted and Volume of the room. For example, What is the ACH of my room (10'x10'x10') using an existing exhaust fan rated at 200 CFM? ACH = (CFM x 60) / Vol of Room ACH = 200 x 60 / 1000 ACH = 12 Most standards list...

The last 2 post are correct. Autocad is not a parametric modeler like ProE. It does not have the capabilty to change an object if you change the dimension. If you want to change the dimension of a line...you have to manually stretch or extend the line.

ESP should include items outside the unit. Items such as ductwork, elbows, transitions, filters outise unit, silencers, dampers, etc.

It is possible to have the H2 sensor activate a damper actuator but the important question is whether your local jurisdiction will allow it. Check with your building dept & fire dept.

Also, make sure the exhaust fan is of spark/explosion construction and the powered by emergency power (if available).

I agree with Walkes... Design a passive exhaust system to be activated when the H2 sensors alarms at 1% or 2% H2 concentration by volume and also shut down the AC system. During normal operation the room can be 100% recirculated. A simple formula we use to calculate the minimum required...

In out area, Liebert provides excellent customer service regardless of the size of the project. They help us out on projects that uses one 2 ton mini-mate just as thouroughly as a project that uses 20 mini-mates. We always specify Liebert unless the owner wants another manufacturer. I know I...

Here is some rule of thumb that may help. One nominal ton of Air conditioning = 12,000 BTUH One nominal ton of Air conditioning = 400 CFM Standard Office Building CFM per square feet = 1 to 1.2 Standard Office Building square feet per ton = 333 to 400 --------- So your 5 ton unit has a...

I agree with York. I would use an independent system, such as an split system (i.e. mr slim). They have their won control and can operate 24/7. Also, size your system for possible server expansion. You never know when they might consider adding more equipments.

JohnP has summed it up pretty well. However, in my opinion...I dont know what good it will do to ventilate 22cfm in a garage. I would consider increasing the amount to 50cfm. The undercut of the door can still support 50 cfm of transfer air from the adjacent space. for this small exhaust...

Thanks for the tip.

Static Pressure: A fan must overcome resistance when pushing air from the discharge of the fan through the duct to some final outlet. This resistance is known as static pressure. Static pressure in a typical duct run is caused by the velocity of the air, type of duct material, elbows/fittings...