Large Air handling Equipment Dehumidification / Litres Per Hour ?

[deluxairhead]

Hi guy's

I'm just new here so bear with me so as I can get up to speed please !

My question is I've been on line looking for information
re : air handling equipment calculation's and the amount of moisture removed, but cannot find anything really that gives me litres per hour rates !

Doe's anyone know where to go to find this out does Trane have any spec's on their equipment ?

" Hope you can help ! "

Deluxairhead

[carlfoster]

Is this on a system already running? I ask because you can plot the temperature and humidities of air on and air off on a psychrometric chart to get the moisture removal.

[frank]

The equation for calculating kg/hr is :

kg/hr = (Vol x delta kg/kg x 3600)/ sp Vol

where:
Vol = Volume of air (m3/s)
Delta Kg/kg = Difference in Moisture content of air before and after cooling process
3600 = Constant to convert between Hr/sec
sp Vol = (Specific Vol(start) + Specific Vol(finish))/2

All details obtained from Psychrometric Chart

[deluxairhead]

Hi guys

Thanks for the heads up Frank I think I'll be able to get a calculation together, cheers again !

Wayne / Deluxair

[frank]

Thanks for the response/feedback Wayne.

[Abby Normal]

You can plot entering or leaving conditions on a chart

You can also convert latent cooling capacity into mositure removed.

Take about every 1060 btu of latent heat as a pound of condensate.

Not into converting to joules and kg for you at the moment. it

[Sandro Baptista]

The equation for calculating kg/hr is :

kg/hr = (Vol x delta kg/kg x 3600)/ sp Vol

where:
Vol = Volume of air (m3/s)
Delta Kg/kg = Difference in Moisture content of air before and after cooling process
3600 = Constant to convert between Hr/sec
sp Vol = (Specific Vol(start) + Specific Vol(finish))/2

All details obtained from Psychrometric Chart

Frank,

I would consider the sp Vol and the air volume at the inlet of the cold coil. At this point you know exactly what's the mass flow (this value is invariable, not influencied by the temperature).

[Gary]

A bucket and a stop watch?

[Sandro Baptista]

yes that's right Gary

[frank]

Frank,

I would consider the sp Vol and the air volume at the inlet of the cold coil. At this point you know exactly what's the mass flow (this value is invariable, not influencied by the temperature).

But the mass flow IS influenced by the temperature.

As I said, all data taken from the Phsychrometric chart. When you plot the cycle out, there is a difference (kj/kg) on the mass flow lines.

[Sandro Baptista]

Frank,

If you can measure the volume flow at the inlet of the cold coil at a know temperature you already know the mass flow. Then based on the temperature and H.R. on point 1 and point 2 you can calculate the massflow of moisture that goes out (condensed water).

I'm sorry I didn't understand what you mean with "there is a difference (kj/kg) on the mass flow lines".

kg is kg of dry air not total mass.

[dougheret0]

You can find detailed instructions in my book on how to calculate the process line of an air conditioning system on a psychrometric chart. The book is HVAC Design Manual – A Mechanical Designer’s Guide to Design of Small Commercial and Institutional HVAC Systems and is available for free download at my web site, www.nettally.com/doughert. See chapter 7 for psychrometric calculations and how to avoid moisture problems in an air conditioned building.

The replies you already received are correct, so what you will get from my book is a more complete guide to psychrometrics.

[Gary]

Or you can use a bucket and a stop watch.