desuper heater coil causing me problem

[pocketbikeuk]

i replaced my desuper heater coil with a longer and tighter wound one but now it takes my system 5 mins to pull down as im guessing it cant get a high enough pressure to condense the r290 or that it is slowing down the refrigerant flow so much that it takes ages to pull down to temps when the compressor is cold but when it is warm pull down times are fine around 15sec. i guess i need to remove the desuperheater or make it smaller i also find that load temps arent that great with the new coil does this mean that a oversized condenser would also be bad for a system my condenser is 24cm wide and 19cm high but it never even feels warm i expect nearly all the heat is being removed by the desuperheater which is nice and warm. any comments on this are much appriciated. :)

[craig588]

Why are you using one in a single stage?

[boardy]

Why not? I have 1 on my S/S aswell. Loads of the guys I know have them on aswell.

Seems to stop the massive temp difference between load and idle temps pretty nicely.

Boardy

Edit: I am using a 402/23 blend which may have something to do with it.

[pocketbikeuk]

Why are you using one in a single stage?

just to remove vibration and they look cool but il remove the whole thing 2nite and see the difference. dont they help with high pressure gases like 402 and 410?

[MeltedDuron]

that is exactly why we use them! high pressure gasses need all the help they can get

[Gray Mole]

2 reasons to use a coil on a single stage...

1. to remove vibration if you don't have much of a run of pipe

2. to assist the condensor in a system where it's not enough to condense the refrigerant

Propane hardly needs much cooling to condense nicely, so adding a desuperheat coil is a completely un-needed, and this I think really illustrates the problem that over condensing can give.

Yes, they can 'look cool' but that's not what they're used for really :p:

hehe

Gray

[pocketbikeuk]

2 reasons to use a coil on a single stage...

1. to remove vibration if you don't have much of a run of pipe

2. to assist the condensor in a system where it's not enough to condense the refrigerant

Propane hardly needs much cooling to condense nicely, so adding a desuperheat coil is a completely un-needed, and this I think really illustrates the problem that over condensing can give.

Yes, they can 'look cool' but that's not what they're used for really :p:

hehe

Gray
cool well im gonna unbraze it and when i buy some 410 from srwonline then il put it back in

[expansionvalve]

I have never come across these cooling coils before apart from on these forums, but can see the reasons why they help, I'd just find a good size condenser instead, maybe oversize and fit condenser fan speed switches to keep head pressure at a sweet spot but I guess for size, you guys like to keep things small and compact.

If you think you are overcondensing a little how about fitting some speed controller to the condenser fan, or a high pressure switch switching the fan on and off a certain pressure/temperature,.

just a passing thought.

[Jort]

yeah but a high pressure switch only brings the manufacturings cost up.

just a VR on the 12V 120MM fan is good enough:)

[expansionvalve]

Agreed, it may bring the costs up but it's another toy and some more wires to play with..

[Jort]

Agreed, it may bring the costs up but it's another toy and some more wires to play with..

if you take it that way yeah your right.

played some with the wires today at school :stick: (i can't see any wire's anymore this week) :p:

its from a chiller:
http://www.belgium-coolingsolutions.be/Gip2/spaghetti.JPG :eek:

[Carlz0r]

I have never come across these cooling coils before apart from on these forums, but can see the reasons why they help, I'd just find a good size condenser instead, maybe oversize and fit condenser fan speed switches to keep head pressure at a sweet spot but I guess for size, you guys like to keep things small and compact.

If you think you are overcondensing a little how about fitting some speed controller to the condenser fan, or a high pressure switch switching the fan on and off a certain pressure/temperature,.

just a passing thought.
Would you call a 12"x13" condensor overkill for r290? :p:

[expansionvalve]

That will teach me to read a bit better :slap:

[LukeXE]

2 reasons to use a coil on a single stage...

1. to remove vibration if you don't have much of a run of pipe

2. to assist the condensor in a system where it's not enough to condense the refrigerant

Propane hardly needs much cooling to condense nicely, so adding a desuperheat coil is a completely un-needed, and this I think really illustrates the problem that over condensing can give.

Yes, they can 'look cool' but that's not what they're used for really :p:

hehe

Gray

Do you mean, that if I have got too big condenser (really big, 16''x21'') in 1 stage with r290/r744 inside, it could be worse than smaller condenser ? I have desuperheater coil too, and temperatures really sucks (It's very bad handling load)

High pressure --> 150psi
Low pressure --> 3psi

[Jort]

yeah because you don't have enough pressure before the captube or txv :)

[Icy]

But you should be able to fix that by also using a large compressor right?heh
So i guess if you have a small compressor and a huge condenser its not good... but if you have a large compressor and a huge condenser it should be ok(better).

[LukeXE]

My compressor is probably 3/4HP or 1HP, so it`s powerfull :)

Maybe I`ll try to raise the pressure by adding more co2 or change gas to r22 or 507 ?

[expansionvalve]

yeah because you don't have enough pressure before the captube or txv :)

Not having enough pressure granted:)
but i'd still play with condenser fan speed control before I mucked about with and started removing bits.

[wdrzal]

All you need is 2 to3 degrees of sub-cooling so you have a liquid head at cap tube.If liquid is present pressure is irelavant except to its effect on mass flow.

why are you putting co2 is a ss?

[LukeXE]

All you need is 2 to3 degrees of sub-cooling so you have a liquid head at cap tube.If liquid is present pressure is irelavant except to its effect on mass flow.

why are you putting co2 is a ss?

That question is to me ?

Because I`m talking about my cascade, about her 1 stage ;) I have subcooling on it, cap tube is all freezed.

[Blaster]

All you need is 2 to3 degrees of sub-cooling so you have a liquid head at cap tube.If liquid is present pressure is irelavant except to its effect on mass flow.



very well put

ill just add, the higher the load the higher the mass flow u need :)