I have been to several sites over the past few months where they have complained of units not holding temperature because they have left the doors open on cabinets and walkins, because they think they can use it like an aircon unit to cool down their working area.

After asking staff on site if they're leaving the doors open and them saying no, I have ended up changing fans and controllers, increasing defrosts cycles only to find that the evaporators still freeze up.

On visiting a site for a third time, I noticed that the doors were in fact being left open as I first suspected, I contacted the site managers and let them know of my findings and to inform the staff of the necessity of keeping the fridge doors closed. Except when taking things out, cleaning and stock taking, where they should be switched off. And also that the previous calls are not re calls and are chargeable due to the way that they have been using the fridges and not being honest about leaving doors open.

Over the following weeks the problems were still the same, the units weren't holding temperature, because the evaporator coils were freezing. So I bypassed the door switches on the cabinets, and wired timers into the the walkins controls, so if the doors are open for longer than a minute, the compressor shuts off.

The calls that I'm getting now are exactly the same, the units aren't holding temperature so they had turned them off. I returned to two of the sites and there was nothing wrong with the units, they started to pull down as soon as I switched them on, and they held temperature with no further problems.

Then I got an email from the sites facilities contractor informing that they had received a complaint about the way the refrigeration units were not being looked after, and stating that I had broke the law by allowing the fans to run whilst the fridge doors were open.

They went on to say that the units were not designed to operate this way, and I had ho right whatsoever to modify the design. And by doing so adding an unnecessary heat load to the cabinet causing a non compliance with TEWI, and they were going to inform REFCOM of my actions!

I thought about this and then realised that they had misconstrued the TEWI regs, and what I had actually done was no different from what an aircon unit does when a door or window is opened causing an extra heat load to the system.

I emailed them back and informed them of my reasons of bypassing the door switches, and in doing so I was actually reducing the TEWI by making sure that the fridge doors are always kept shut when access to the fridges are not required. And in fact it was no different to an aircon unit. I also informed them that their annual leak check and service must be well overdue, and that I wanted to see records of past leak checks and services to make sure they were doing their bit and complying with TEWI.

I haven't had a response from them and I have heard nothing from REFCOM, I don't think that I will. It amazes me though when other trades poke their nose into things they do not fully understand, and try tell you that you don't know your job, and then try cause trouble for you.