DAIKIN Drain Pump

[2007eng]

Greetings all.
I am carrying out the installation of more than 300 indoor unit and it is very important to know if there is a check valve in the indoor units (with drain pump) or not?

[Brian_UK]

They do not normally have a check valve as far as I know.

The discharge pipe from the unit should ALWAYS fall towards a the drain outlet.

The pump is not designed to pump against a large head of water.

[Toolman]

They do not normally have a check valve as far as I know.

The discharge pipe from the unit should ALWAYS fall towards a the drain outlet.

The pump is not designed to pump against a large head of water.

I agree with Brian UK , no check valves even on the cassette model as that has a pump but only to lift 300mm then gravity must be involved from there to the outlet of the drain .
If I was putting in 300 of something I would be expecting an answer
from the supplier or Daikin

[Makeit go Right]

There is some info here that might help, plus your local Daikin contact details etc.
http://www.daikinme.com/downloads/default.jsp

[2007eng]

They do not normally have a check valve as far as I know.

The discharge pipe from the unit should ALWAYS fall towards a the drain outlet.

The pump is not designed to pump against a large head of water.

Is that means it is unnecessary to install a check valve?

Why I want to install a check valve? To prevent the water back flow in multiple drain pipes case.
I want to discuss this point, Is it necessary to install a check valve?

[nike123]

Is that means it is unnecessary to install a check valve?

Why I want to install a check valve? To prevent the water back flow in multiple drain pipes case.
I want to discuss this point, Is it necessary to install a check valve?

No it is not necessary to install check valve.
You need to lay condensation pipes in order that you ensure proper drain of water from them by gravitation.
That mean that condenser pump only lift water column to higher point (approximately 0,5 m is max, consult commissioning literature) immediately at location of indoor unit and from that point it should drain itself by gravitation to collection point or collection pipe who must be at lower point.

[Refrigerologist]

When installing multiple drains and they 'tee' into drains from floor levels above, this can lead to a problem of water leaking from the fan coils on a lower level if a drain blocks elsewhere. Rare, but it does happen! I sometimes install a waterless trap HEPvO type into the condense drain if the indoor fan coil is located above sensitive equipment to prevent this from occuring. I always install this type of trap at the end of the condense drain before it enters a soil or rain water pipe.

[2007eng]

this can lead to a problem of water leaking from the fan coils on a lower level if a drain blocks elsewhere.

This is the reason of my check valve idea.

Your solution is very nice, but what is the solution if a drain blocks elsewhere in the floor central drain pipe while the situation of working of indoor pumps and one or more of them is off?

[Brian_UK]

Can you run separate drains from each floor to get around that problem?

[2007eng]

Can you run separate drains from each floor to get around that problem?

No I can't. But this is not solution. I am talking about a leaking from any indoor unit to another if a drain blocks elsewhere in the floor central drain pipe before it enters a rain water pipe.

[Brian_UK]

No I can't. But this is not solution. I am talking about a leaking from any indoor unit to another if a drain blocks elsewhere in the floor central drain pipe before it enters a rain water pipe.

Well then, run separate drains from each unit to a tundish adjacent to the main drain point. That way there will not be any interaction between the units.

Also, correct maintenance of the drains will/should ensure good performance.

[2007eng]

Well then, run separate drains from each unit to a tundish adjacent to the main drain point. That way there will not be any interaction between the units.

Also, correct maintenance of the drains will/should ensure good performance.

Nice Brian_UK, But I have 16 indoor units on the floor and I have 29 floors. What about cost?

[nike123]

Nice Brian_UK, But I have 16 indoor units on the floor and I have 29 floors. What about cost?

What kind of pipes you using for condensate drain?
I usulay using PP pipes for domestic waiste like this:
http://tinyurl.com/2xax6t

I usually starting with 32 mm diameters at Fan-coil and gradually raising diameter as number of connections raising (and for large AHUs) and applying same rules as plumbers for layout practice. No siphons and decline of 1% is mandatory. All branch connections to collector pipe must be from above. leak test at commissioning.
I don't have single case of pipe obstruction or leakage from day one of that practice (more then 10 years).

[2007eng]

I usually using PVC pipes starting with 25 or 32 and raising diameter as number of connections raising like u.
Our service area here about 50 cm from slap to false ceiling and we have a lot of works in this area I can't run separate drains from each unit.

[TRASH101]

When I have done office installations etc. I generaly ran a couple of main drains in (depending on void depth v drain length v unit drain height (modified by pump head where fitted).
The drain preferabley copper would be trapped and air broken before joining main drain or other. Individual air breaks for each unit would be achieved by sizing for 15mm or 22mm (depending on unit requirements) draining into open connections on the main condensate drain. If you size the main drain correctly, keep it rigid enough and ensure a good fall (I would suggest no less than 1:40) then you will have no trouble plus its easy to add rodding points and you can intorduce biocide and stuff at any or all the air breaks.

[Refrigerologist]

This is the reason of my check valve idea.

Your solution is very nice, but what is the solution if a drain blocks elsewhere in the floor central drain pipe while the situation of working of indoor pumps and one or more of them is off?

Generally all condensates are run in 32mm (11/4") pvc waste as per manufacturer's requirements, fall is minimum 1mm in 900mm.

The waterless trap solution will not cause you any problems elsewhere. If the main drain blocks then the water will back up in the pipe and find its way out of the lowest point, that is the lowest fan coil. Waterless traps can prevent this except for where a large column of water builds up in the main stack and reverses the bladder in the trap. But if the main stack blocks you would be in deep doodoo anyway!! Tundishes can be useful too, but you need to be careful, if a stack pipes back up. I have seen a couple of building flooded due to rain water pipes blocking and water pouring back out throught the tundish!

The main reason I use waterless traps is they do not dry out in the heating season, so we don't get foul odours coming out of the fan coils.

[Brian_UK]

Have you considered using a vacuum condensate removal system?

http://www.jetvac.ca/FAQ.htm

[2007eng]

Boget...Boget..!

[Brian_UK]

Boget...Boget..!

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[Josip]

Hi, Brian_UK

Boget...Boget..!

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maybe this...

http://www.urbandictionary.com/define.php?term=boget

Best regards, Josip

[2007eng]

Sorry I mean Budget.

[Matty]

Nice Brian_UK, But I have 16 indoor units on the floor and I have 29 floors. What about cost?

I do this set up day in day out...run a central pipe 1"1/4 from the highest point gradually falling until you t into a soil stack using a strap on boss...... then come off each unit in 3/4 pipe and drop off into the central pipe....

[Brian_UK]

Sorry I mean Budget.

OK, I wasn't sure whether to be offended or not

[2007eng]

OK, I wasn't sure whether to be offended or not

Don’t worry this is my mistake.Thanks .