might be stupid Rad question

[Gutternutz]

Wondering... will a 120mm X 60mm deep rad be equivalent to a 240mm x 30mm thick rad??? Thanks

[machiningguy]

DR0023 v1
©PBA Energy Solutions Ltd
3
3.
Heat/Cooling
load capacity
This method calculates water volume in heating and cooling systems based on heat load capacity
.
This
is ONLY valid for Commercial installations, as Domestic boiler
s
can be significantly oversized for
the property.
With this method
the
thermal capacity
(k
W)
of the boiler/
chiller
should be known.
Heating systems formula
kW x 0.014
= m
3
m
3
less
%20
=
Estimated
Water Volume in the system
By applying the
kW x 0.014 = m
3
formula the m
aximum
water volume
of the boiler
is calculated;
then
subtract 20%
(typical heat engineering boiler sizing
tolerance margin
)
to give the
estimated
water volume in the system
.
In making this calculation i
t
is very
important to know
the
accurate
kW
heat capacity
of the active
boilers. For example there may be a primary
boiler is the main feeder and
a sec
o
ndary/backup
boiler. The
c
alculat
ion must use the
kW
of
the
heating needed for the bu
i
lding, and exclude backup
and capacity tolerances.
NOTE:
20% is a typical boiler capaci
ty tolerance margin, but this may vary. This exact boiler capacity
tolerance may be available in the original Heat Engineering calculations.
EXAMPLE
S
E
xample
1
The system has one
1400 kW
boiler
.
1400
k
W
x
0.014
=
19.
6 m
3
19.
6 m
3
-
%20
=
15.
68 m
3
e
stim
ated water volume in the
system.
Example 2
T
he system
has two boilers which are working together,
(both are 1400 kW).
In this situation the
total k
W
(the working load)
of the
boilers
must be used in the formula
(1400 kW + 1400 kW)
* 0.014 =
39.2 m
3
39.2 m
3
-
%20 =
31.36 m
3
estimated water
volume in the system.

Here's another Doosie

Sensible Heat

The sensible heat in a heating or cooling process of air (heating or cooling capacity) can be calculated in SI-units as

hs = cp ρ q dt (1)

where

hs = sensible heat (kW)

cp = specific heat of air (1.006 kJ/kg oC)

ρ = density of air (1.202 kg/m3)

q = air volume flow (m3/s)

dt = temperature difference (oC)

Or in Imperial units as

hs = 1.08 q dt (1b)

where

hs = sensible heat (Btu/hr)

q = air volume flow (cfm, cubic feet per minute)

dt = temperature difference (oF)
Latent Heat

Latent heat due to the moisture in air can be calculated in SI-units as:

hl = q ρ hwe dwkg (2)

where

hl = latent heat (kW)

ρ = density of air (1.202 kg/m3)

q = air volume flow (m3/s)

hwe = latent heat of vaporization of water (2465.56 kJ/kg)

dwkg = humidity ratio difference (kg water/kg dry air)

estimate humidity with the Mollier diagram

Or for Imperial units:

hl = 0.68 q dwgr (2b)

or

hl = 4840 q dwlb (2c)

where

hl= latent heat (Btu/hr)

q = air volume flow (cfm, cubic feet per minute)

dwgr = humidity ratio difference (grains water/lb dry air)

dwlb = humidity ratio difference (lb water/lb dry air)

1 grain = 0.000143 lb = 0.0648 g
Psychrometric chart

Total Heat - Latent and Sensible Heat

Total heat due to both temperature and moisture can be expressed in SI units as:

ht = q ρ dh (3)

where

ht = total heat (kW)

q = air volume flow (m3/s)

ρ = density of air (1.202 kg/m3)

dh = enthalpy difference (kJ/kg)

estimate enthalpy with the Mollier diagram

Or - in imperial units:

ht = 4.5 q dh (3b)

where

ht= total heat (Btu/hr)

q = air volume flow (cfm, cubic feet per minute)

dh = enthalpy difference (btu/lb dry air)

Total heat can also be expressed as:

ht = hs + hl

= 1.08 q dt + 0.68 q dwgr (4)
Example - Heating Air

An air flow of one cfm is heated from 32 to 52oF. Using (1) the sensible heat added to the air can be expressed as:

hs = 1.08 (1 cfm) ((52 oF) - (32 oF))

= 21.6 (Btu/hr)

Sensible Heat Load and Required Air Volume Chart

Sensible heat load and required air volume to keep the temperature constant at various temperature differences between make up air and room air:

Sensible heat and required air volume

Sensible Heat Load and Required Air Volume Chart (pdf)

Latent Heat Load and Required Air Volume Chart

Latent heat load - humidifying and dehumidifying - and required air volume to keep temperature constant at various temperature differences between entering air and room air are indicated in the chart below:

Latent heat and required air volume

Latent Heat Load and Required Air Volume Chart (pdf)

SHR - Sensible Heat Ratio

The Sensible Heat Ratio can be expressed as

SHR = hs / ht (6)

where

SHR = Sensible Heat Ratio

hs = sensible heat

ht = total heat (sensible and latent)

Calculate Water Volume
GENERAL
For many closed water and recirculating open cooling systems, the system volume is needed to determine the amount of inhibitor or biocide that is needed for accurate chemical treatment. To calculate water volume, some of the old “rules of thumb” such as five times recirculation rate just are not accurate enough for most applications. For systems where the estimated volume is greater than 10,000 gallons, an easy method to determine actual system volume uses addition of a known concentration of molybdate, measurement of system molybdate concentrations, and a calculation to obtain an accurate volume measurement.

PROCEDURE
1. Estimate the system volume by measuring the sump of the tower and the water level in it. Multiply the number of cubic feet of water by 7.5 to get the number of gallons. Then add 10-20% additional water for piping, etc.

2. Estimate the amount of Q-TRACE 10 required to obtain molybdate concentrations in the range of the molybdate test method being used. One gallon of Q-TRACE 10 in a 10,000 gallon system will develop a molybdate residual of 21.5 ppm as MoO4-2 (Molybdate) or 14.4 ppm as Mo+6 (Molybdenum).

For example, to measure 3 ppm as MoO4-2 in a system containing 25,000 gallons, add 0.35 gallons of Q-TRACE 10. (One gallon of Q-TRACE 10 in 25,000 gallons provides 8.6 ppm MoO4-2 [21.5 ppm MoO4-2 X 10,000 gal/25,000 gal = 8.6 ppm}; to obtain 3 ppm MoO4-2, 0.35 gallons of Q-TRACE 10 would be required [1 gallon Q-TRACE 10 X 3 ppm /8.6 ppm = 0.35 gallons].)

3. Begin the system volume measurement. First run a molybdate test on the recirculating water to determine if any molybdate is in the system. If a open recirculating system is being tested, it is best if there is no load on the system and the blowdown is closed. Next, add the pre-measured amount of Q-TRACE 10 to the circulating water in an area where good mixing can occur. The water should then be allowed to circulate and mix for 30 minutes and a second test for molybdate run. Continue testing molybdate every 15 minutes for another hour or until the molybdate results have stabilized. In most cases, the results will be stabilized after no more than three tests and testing can be discontinued at that point in time.

CALCULATION AND INTERPRETATION OF RESULTS

Sysem. Vol. gals = [(4470 added gals)*359,712]/ppm Na2MoO4 measured

Once a know volume of Q-TRACE 10 has been added to the system and thoroughly mixed, the molybdate residual should be measured and plugged into the following formula:

(Q-TRACE 10 added in gallons) X 599250 = System Volume in Gallons
(PPM Molybdate tested in System)

1 PPM Sodium Molybdate = 0.6 PPM Molybdate = 0.4 PPM Molybdenum

SAMPLE CALCULATION

Let’s suppose we have a system where the tower that is 24 ft long, 12 ft wide, and has 18 inches water in the sump.
1. 12’ x 24’ x 1.5’ x 7.5 gal/cu.ft. = 3240 gallons water in the sump. Adding another 10-20% for water in the system, the estimated system volume is about 3800 gallons.

2. If one gallon of Q-TRACE 10 were added to this system, 56.6 ppm of MoO4 would be developed. (21.5 ppm MoO4-2 X 10,000 gal/3,800 gal = 56.6 ppm MoO4). To develop only 3 ppm MoO4, add 6.8 ounces of Q-TRACE 10 (1 gallon X 3 ppm/56.6 ppm = 0.05 gallons or 6.8 ounces).

3. Assuming the MoO4 in the system is measured at 3.4 ppm, then true system volume can be calculated: 3.4 ppm MoO4 / 3.0 ppm MoO4 = 1.13 So, volume is 1.13 X 3800 gal. = 4307 gallons.

0.05 gal F4470 x 10.43#/gal = 0.5215#
0.5215#


Using Salt to Determine System Volume:

GENERAL
For many closed water and cooling tower systems it is good to have a close idea of the volume of water in the system so the amount of inhibitor or biocide needed to adequately treat the systems can be determined. Some of the old “rules of thumb” such as five times recirculation rate just are not accurate enough for most applications. Thus, a very simple salt test can be performed to give very accurate estimates.

PROCEDURE
To conduct the test, ordinary salt can be purchased from the grocery store or, if a lot of tests are to be run, 50 lb bags can be purchased from a chemical distributor. It is best to estimate the number of gallons in a system to select an amount of salt which will give a reasonable result. Typically, it is best if about 1 lb. of salt is added for each 1000 gallons of water in the system. A good starting point for estimating is to measure the sump of the tower and the water level in it. Then multiply the number of cubic feet of water by 7.5 to get the number of gallons. Then add 10-20% additional water for piping, etc.

First, run a chloride test on the circulating water to obtain the base chlorides in the system. If a tower system is being tested, it is best if there is no load on the system and the blowdown is closed. Then, a pre-measured amount of salt is added to the circulating water in an area where good mixing can occur. The salt solution should then be allowed to circulate and mix for 30 minutes and a second test for chlorides run. Then continue to test the chlorides every 15 minutes for another hour or until the chloride results have stabilized. In most cases, the results will be stabilized after no more than 3 tests and testing can be discontinued at this point in time.

CALCULATION AND INTERPRETATION OF RESULTS
Let us suppose we started with a tower that was 24 ft long, 12 ft wide and had 18 inches water in the sump. Thus, using the formula above, 12 x 24 x 1.5 x 7.5 = 3240 gallons water in the sump. Then, since there is likely another 10-20% water in the system, a dosage of 4 lbs salt should put the results in a decent range so this dosage is added to the sump near the suction for the circulating pumps. Prior to the addition, the chloride test on the water was 48 ppm (as chlorides) or 80 ppm (as sodium chloride). NOTE: It is very important to know whether the test being used measures chlorides as Cl or as NaCl.

After circulating for 30 minutes, the second test gave a chloride content of 110 ppm (as Cl) or 183 ppm (as NaCl). Then, 15 minutes later this result increased to 116 ppm (193 ppm) and then a third test showed 114 ppm (190 ppm). It can then be assumed the results had stabilized so the chlorides had increased by 116 - 48 or 68 ppm (as Cl) or 184 - 80 = 104 ppm (as NaCl).

Therefore, since 1 lb salt per 1000 gallons should increase the sodium chloride content (NaCl) by 120 ppm or the chloride (as Cl) content by 72 ppm, the amount of water in the system is calculated as follows:
Theoretical sodium chloride increase 120 ppm/actual increase 113 ppm x 4 lbs = 4,248 gallons, or
Theoretical chloride increase 72 ppm/actual chloride increase 68 ppm x 4 lbs = 4,235 gallons.

NOTE: The above differences are due to rounding of the numbers (NaCl = 60% Cl). Thus, for calculating the biocide additions or closed system inhibitor additions, a good safe estimate for system content would be 4500 gallons.

I hope this was helpful

[Gutternutz]

[fuji]

I believe in general surface area matters more. A slim 240 will beat out a thick 120 even when slim is push and thick 120 is push/pull

What I'm not sure about though. Does a 420 beat out a 480. A 420 has more area 140 * 420 vs 120 * 480. But how much of that is lost due to 3 fans vs. 4 fans.

[Necrodead]

I like to use this page to compare most radiators: http://www.xtremerigs.net/2015/02/11...nd-2015/all/1/

Every rad is a little different and performs differently at different fan speeds and setups. Although, the difference is pretty small when it comes to thickness, so I usually go for thin rads to save space and money. Actually sometimes thicker rads will perform worse than their thin counterparts at slower fan speeds, especially when not in push/pull config.

What I have come to realize from experience is that the cooling is really dependent on your fans and speed of those fans, and that radiator choice has a lot less to do with cooling. I'm not saying there isn't a difference, however better fans with more static pressure will increase your cooling more than say buying a thicker radiator.



as you can see at a relatively normal speed like 750rpm there is only 40 more watts of power dissipated for a radiator more than 2x thicker. (alphacool monsta vs EK SE) and this is an extreme case. In fact the Hardware labs nemesis GTS is only 30mm thick and only dissipates only 10W less than the 80mm(?) thick alphacool monsta. And if you look at the 1850rpm chart, the thicker monsta rad underperforms the 60mm alphacool rad of the same design, but normally that is not the case, but it does prove my point that thicker is not always better.

[DazMode]

Dual will beat single.

[Gutternutz]

K thanks for the replies. Ummm I can get a NexXxos Monsta Full Copper Radiator 240 for $80, EK pastel white was run through it... not sure about that liquid and if there are any problems with it, but anyways, is a DDC enough to push through that rad? Seems awfully thick.

[DazMode]

Monsta is less restrictive than some of smaller rads.

[Gutternutz]

Thanks Daz... turns out that rad won't even fit my case hahaha... just gonna get one off of you =) March break sale? Might just wait cause I'm gonna be ordering a lot of stuff

[Gutternutz]

Another question... Alphacool - NexXxoS XT45 Full Copper 240mm VS. DarkSide - Dual LP240 Extra Slim Radiator VS. EK-CoolStream PE 240

[Hooded]

Darkside LP240 best bang for your buck.

[Gutternutz]

Thanks. If I can't do a push pull, would you recommend a thicker rad?

[Hooded]

Only if you're trying to cool a CPU and a GPU. A second rad be it a 120 or 240, would give you better results than push-pull or a thicker rad

[Gutternutz]

Doing just a CPU loop.

[Gutternutz]

Huh.. after pricing everything out... I am better off going with a Daz kit, or EK predator... go figure. Hopefully Daz will supply kits for AMD AM4.