Evap fans spinning the wrong way?

[marc5180]

I got sent to a site today to fit a new evap fan motor on a walk in cooler on R22 since the old one had burnt out.

There are 2 evap fans side by side i only replaced the one of them.

After i had replaced the fan and switched it on i noticed that the fans were not pulling the air from the back of the coil and blowing it out into the room but were in fact pulling the air from the room over the motor and onto the coil, with the airflow coming out of the back of the coil and blowing onto the coldroom wall which was about 8 inches away (see picture)

Since the airflow was blowing onto the wall, i noticed that even after a few hours the wall had become dirty (see pic)

The fans are single phase anti clockwise rotation fans and are going the way that they are made but i think they shouldn't have anti direction motors fitted.

I understand that the fans should run counter flow to the refrigerant but i don't think they do.

Anyone ever come across this?

[monkey spanners]

I think the evap has been fitted the wrong way round, lots of those little evaps blow through the coil whereas all the big ones suck through, looks like a searle unit, have a word with climate technical tomorrow and see.

Jon

[Brian_UK]

I agree with MS, unit mounted the wrong way round.

[multisync]

In the old days it was often done to fit the evap to blow against the back wall. It stopped the cold dry air blowing directly onto the produce

The evap is a searle the fan guards are the clue. If you've fixed it I would move on as it's been like that for years.

[Gingerair]

3+1, Cooler fitted wrong way round. It'll work, just have crap air distribution in the room. Tell them to make sure the area around the cooler is clear & keep the door shut.. :(

[marc5180]

Well thats a new one to me.

It did seem to cool the room down and all the pressures/temps were fine but the fact that the back wall was gtting dirty was something that made me question it.

As suggested i'll leave it be.

[nike123]

They are spining as they supposed to spin. As others alredy said, evaporator is fited 180° wrong way and fans side should be near cold-room wall as on this picture.

http://i40.tinypic.com/14o9e1s.jpg

You could fit evaporator properly or try to reverse fan rotation direction by changing main and auxilary winding on condenser (if they have same resistance) but I am not sure that that will produce same air flow across evaporator, and I am sure that air distribution in cold-room will be very bad in upper portion of cooler. If it is positive temperature, some air deflectors could be fited to direct air flow upwards.

[1torr]

Yep, its been put up the wrong way round

[Gary]

The easy way to reverse it is to get fan blades with the reverse pitch... but I would leave it as is.

[tony--1]

The easy way to reverse it is to get fan blades with the reverse pitch... but I would leave it as is.

dont change anything thats the way they were fit in the old days . start messing around with blades . just asking for problems .

[nike123]

thats the way they were fit in the old days .
You are kidding! Or you not?:eek:
Who, whit at least ounce of brain, will fit evaporator to blow air directly in wall behind evaporator.
That was fitted by some moron who saw evaporator like that first time in his life, and was so much blind that can not be able to see mounting instructions which coming inside packaging and was acting by his "rich experience" since all "normal" evaporators are fitted with fans at front of evaporator.

Thanks Good that "old days " are history now! Or did they not?