Coil Output - any ideas?

JimGPE_3

Okay, first the easy stuff. The fan rpm is not significant.

Usually one runs air through a coil at or about 500 fpm, so 33 sqft x 500 = 16500 CFM. Over 8000 sqft floor area, this is 2 CFM/SqFt outside air, which is a LOTTT of outside air. WAAAAY more than is required by code for a common or garden variety office building. Probably not correct.

Suggestions:

Get the air handler make, model, serial number and contact the manufacturer for more data - e.g. the airflow the unit was designed for.

See if the owner has any drawings on this system. Look up the capacity in BTUH's or CFM's and air in and out temps.

Get an airside contractor to measure the airflow.

Measure inside free area h & w of the supply duct after the transition from the unit discharge and post the size. That will translate into a ballpark CFM.

Once you get CFM, load in BTUH = CFM x (Tout - Tin) x 1.08.

You don't have nearly enough info, and these are questions you get to ask!!!! I've been doing this for 25 years, and I would have to ask them.

Good luck.

Terry

glycol isolation

I have been asked to design a system to isolate a make up air coil from the rest of the system (Glycol isolation). The building is a small office complex 4 stories, aprox 2000sq ft per floor.

I am having difficulty determining the btu capacity on this coil as my customer has given me little to no information.

The Coil is 44" x 108" (33 sq ft), fed with 180F Glycol solution. No CFM, only motor RPM (1725) :,(

Can anyone help me in determining to POTENTIAL btu load required by a coil this size?

ANy Help would be highly appreciated...

Terry T

Terry

Manufacturer Info

I did find out that it is a SiROCCO Type: V Size 318. No other specs. Not finding anything on search for "Sirocco" Has anyone ever heard of this make ?

*twidling thumbs*

PS - Man you guys reply fast!

Terry

JimGPE_3

> I did find out that it is a SiROCCO Type: V Size

> 318. No other specs. Not finding anything on

> search for "Sirocco" Has anyone ever heard of

> this make ?

>

> *twidling thumbs*

>

> PS - Man you

> guys reply fast!

>

> Terry



No good. Never heard of SiROCCO. Absolutely not drawings available? Are you bidding this competitively?

How about that duct size?

Just to give you a perspective, if this really is a common or garden variety office building, International Mechanical Code calls for 7 people/1000 sqft, and 20 CFM/Person, or .14 CFM/SqFt outside air. A far cry from the 2 CFM/SqFt given above.

I'm clueless. This guy HAS to give you more info.

JimGPE_3

No good. Never heard of SiROCCO. Absolutely not drawings available? Are you bidding this competitively?

How about that duct size?

Just to give you a perspective, if this really is a common or garden variety office building, International Mechanical Code calls for 7 people/1000 sqft, and 20 CFM/Person, or .14 CFM/SqFt outside air. A far cry from the 2 CFM/SqFt given above.

I'm clueless. This guy HAS to give you more info.

As a last ditch effort, what size and material pipe goes to the air handler now?

Terry

impressed

Thanks for all the help so far. This job is not being bid as per sai. My Customer has the job and I will be supplying the material to isolate unit via HE (glycol). But I do want to ensure that my design will infact provide adequate without overkill.

I have asked the Contractor to get me the Duct Size,pipe sizes, Etc. and expect answer this week.

The system he is working on is very old and the owners are tight (little money in coffers). It would have been prudent for them to do a COMPLETE retrofit otherwise..

Thanks again for the help !

Regards,
Terry

Dan Peel

Try this..

Run a heatloss on the building and set up for flows and temp drops based on this information. How many rows in the coil, how's it headered and what's the # of fins per inch? You're working with a huge (by my standards) coil size - is it an old steam coil or hot water? Enjoy...Dan

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

JimGPE_3

With all due respect,

He did say this is a makeup air coil. To me that means 100% outdoor air for ventilation or makeup.

Makeup air load is a function of only the amount and temperature of the outside air. A building load would not be illuminating, unless there is something here I don't understand. Which would not be the first time....

Dan Peel

The whole question

I just re-read and you are correct. Missed the makeup last time round. Thanks, Dan

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"