Walk in cooler without defrost

[VTP99]

[QUOTE=Navy06;14937321 you will always need a defrost on any system.[/QUOTE]

[Tommy knocker]

Stick a tstat of a walk in cooler in the coil? What? You should never do that! Return air is where the bulb should be at, t-stat set to cut out at 32 degres in ice water(calibrate). The numbers don't always match up. Super heat at 10-12 degrees with 4 x 30min defrost. The lowee cutout will ensure proper food temp coming out of the w/i/c. These defrost are needed in the south, with the warner air and high humidity situations. This is an off cycle defrost. You should be good, but if they call back with a warm box. Take the timer and be done with the call.

Never is a big word. Personally I prefer bulb in coil over timer on WIC for all the reasons 2SAC said. More reliable better control. Not saying timer is wrong at all but in my 23 years in this field I have found it less effective then bulb in coil.

[MicahWes]

I have seen maybe 5 (standard TXV style) walk-ins with sensing elements in the coil in maybe nearly 1000 walk-ins. WHY are sensing elements in the coil more reliable with better control? Why don't all the WIC manufacturers use this system of control if it is hands down superior? Cost certainly isn't the concern.

[Tommy knocker]

I have seen maybe 5 (standard TXV style) walk-ins with sensing elements in the coil in maybe nearly 1000 walk-ins. WHY are sensing elements in the coil more reliable with better control? Why don't all the WIC manufacturers use this system of control if it is hands down superior? Cost certainly isn't the concern.

In 90% of WICs it's not nessisary nor is a defrost timer. But 10% of them will be let's say special. Prone to frosting up for non refrigeration system issues. The bulb in coil is a more effective way to control this frosting because it will shut comp off at the onset and start comp as soon as coil reaches cut in temp,too warm for frost to exist. Where as a timer is all about timed cycles. Prop door open 10 minuts after a defrost cycle on a humid day and a service call and manual defrost are likely.

[Capz]

T-stat bulbs in coils function just as a refer unit using a Ranco low pressure control switch for temperature control as you might see on smaller/older reach-in's. I've experimented with either/or on 10' pizza make tables and the large retarders and compared watching suction temps. It's kind of neat and a good study in refrigeration theory.