LW4000-weeping-temperature settings-air lift doors?

[MDrost1]

Hello,
I live in west Michigan where the winters are schizophrenic to say the least. I have a LW 4000 about 40 feet from my equipment room, well insulated trough with heat tape(3 watt I believe)floor heat(though an under sized boiler, but keeps ice from forming) and air lift doors.

I was wondering if anyone can give me advice as to how to set my "weep" settings once the doors come down for the winter. I am tentative to mess with them too much as I don't want a freeze up.

For folks in similar conditions with similar setups, what do you do? Currently I have my weep turn on at 40 degrees to constant weep. That's probably over kill, but I have no idea what the thresholds can be pushed. Your advice and expertise would be much appreciated!

 

[GoBuckeyes]

Are you saying with two doors and floor heat you weep your machine constantly once the outside temp is below 40?

We run M5's with only one door and get away with blowing down the machine with air after a wash. Thats good down to about 15-20 degrees. Once the temp drops to that we switch to hot weep which is pulsed.

We run our L4000's with one door and pulse weep that with hot water because we only have a single compressor for two units.

If I were you, I would simply blow the machine down 3 times with high pressure air after a wash. I would also set up a weepmiser to come on when the outside air drops to around 15 and then run its program based off of your in bay air temp. At midnight when nobody is washing and your doors haven't cycled Ill bet your bay is toasty warm, no need to be full on weeping water for no reason.

 

[MDrost1]

Yeah, I think you understand my dilemma.

First things first. With two doors, floor heat and the LW 4000 cycle weep to ambient bay temp, I should be good with no freeze ups? I am cautious : ).

Also, how do you have the blown down setup? Curious how that works. Thanks!!!

 

[gearhead]

I run M5s with Air Lift roll ups on each end. I have my weep set @ 35 deg. and it is intermittent down to around 30 deg? Not positive on that because the bay temps haven't been that low since I added the doors. Never have issues with freeze ups. As long as you can monitor bay temps you should be good. If the bays get too cold, then you weep a little. That's when I bump the floor heat a little. I also keep an eye on the entry/exit pads for icing. May have to adjust for that also. Some owners prefer to just crank up the floor heat and leave it. I like to run it as low as possible without weep or pad icing.

 

[MDrost1]

Where are you guys located? Out of curiousity.

 

[koliver]

Weep is controlled by the bay temperature probe. The on and off times for the cycled weep system are as follows:

DEGREES BELOW WEEP SET POINT AMOUNT OF TIME WEEP WATER ON/OFF
less 0 degree F always off
1 deg. - 3 deg. F 288 seconds off, 32 seconds on
4 deg. - 6 deg. F 256 sec. off, 64 sec. on
7 deg. - 8 deg. F 224 sec off, 96 sec. on
9 deg. - 11 deg. F 192 sec off, 128 sec. on
12 deg. - 13 deg. F 160 sec off, 160 sec. on
14 deg. - 15 deg. F 128 sec off, 192 sec. on
16 deg. - 17 deg. F 96 sec off, 224 sec. on
18 deg. - 19 deg. F 64 sec off, 256 sec. on
20 deg. - 21 deg. F 32 sec off, 288 sec. on
more 22 deg. F always on

 

[gearhead]

Central Ohio

 

[MDrost1]

Gotcha. This is great info. I suppose I should have asked how far the IBA is from your eq room as well. My IBA is about 40 feet.

 

[gearhead]

My farthest bay is 32ish feet from the mech room. I'm assuming you are concerned about the plumbing in the troughs by the question being asked. I use a temp gauge with a min max read out to monitor my trough temps. I check it in the mornings to see what the low temp is over night. I have pipes that run from the floor heat boiler that go thru mine and always have good heat there. You may be able to monitor the same way. With the doors and the floor heat, Your bay(s) will be good if the floor heat is working properly. Your weep then becomes your back up if the doors and/or the floor heat fails. The critical point becomes the path to the bay(s). The troughs. They must be kept warm. If you cant do that then you are forced to weep. So if your heat tape can accomplish that, your good to go. The heat in my troughs never goes below 40 degs. I also have one of those remote weather station temp gauges you get at the big box store to monitor attic temps to let me know when to start worrying about the troughs. Cheap and works well.

 

[MDrost1]

Gearhead,

Thanks for the advice. I did put a wireless temp gauge in the trough at the end where it meets the IBA bay. Today we officially reach the teens. I am going to keep an eye on the temps. All is going well for now. Thanks for your help!