fan coil unit refurbishment

[petite27]

Hi all

I have recently been asked to carry out some refurbishments to 60 fan coil units with one of my customers and this is not my area of expertise. They are 4 pipe units with 3 speed fan. we are requested to change the motors, filters and inspect the condition of all the 15mm pipework valves, clean internally etc from the corridor connections.

The concern i have is that the customer has aready ordered the new controls and although they are thermostat type he is requesting i replace the 4way valves with a seperate electronic 2 way valve for for both the heating and cooling coils. this will effectively just be providing full on or fully off for each coil.

Does this sound ok, or would retaining the 4 way valves be most sensible.

also any good links for correct pipework connections to fan coil units as the valves and connections are different at every fcu..

[The Viking]

There is a big issue going from 4 port to 2 port valves.

4 port valves diverts the waterflow when not needed.
2 port valves shuts the waterflow off when not needed.

You see the difference?
Depending on what controls the pumps you might be OK...
Generally if the pumps are pressure controlled via an inverter it should work with 2 port valves.



.

[al]

4 way valves allow water to divert when valve is shut, a 2 way valve shuts fully and drives the pressure up in the system, a pressure transducer normally reacts to slow or shut off the pump. Leave the valves as 4 way, unless you can rebalance the system etc.

al