Why it doesn't matter if your heat pump isn't level.

I'm going early on this one, i thought you might all be busy watching the football on Sunday night.

I recently posted that I had some amazing adjustable feet from Kevin Carling for my heat pump which meant I could get it level, despite not having a concrete base. The heat pump police went bezerk and said if the unit wasn't level it would be disastrous.

What actually happens if your heat pump isn't level??I thought I would look into it.

First off heat pumps do look better if they are level, the photo above is of a fella I used to work with, Hes stood in front of a condenser compound. As you can see none of the units are level, they look awful and they are working perfectly. It was taken in Seoul, South Korea on a night our with the engineers who actually design and build these heat pumps. We pissed ourselves with laughter, they said "its ok, the kits running. All is good". What would they know?.

So lets actually look at what's in the box and what happens if its not level.

The tin work, all the covers and grilles, they dont care if they are level or not, they are just bits of tin and plastic

The fan motor and blade, again this is securely mounted in the unit and will operate perfectly well even if they are put in upside down. Fans can be mounted at any angle.

The refrigerant coil (evaporator in a heat pump) condenser in an air con unit. All refrigerant coils like to have liquid refrigerant entering in the bottom, and vapour leaving at the top, so if they were upside down they would moan a bit, but not being level makes no difference to them at all, they are just coils of pipe.

The water to refrigerant heat exchanger, the water is pumped so it doesn't care if its level or not, neither does the water pump itself, water pumps work whatever angle you put them in. The refrigerant side of the plate is the same as the refrigerant coil, it will work ok level or not.

The electronics, The printed circuit boards literally couldn't care less what angle they are installed in, so they dont have to be level either.

blimey we are running out of options here.

And finally the compressor. The compressor is basically a motor and a pump inside a black steel box, in domestic fridges the compressors are free floating in the shell, the motor etc is suspended on springs, If you take the compressor out your fridge and shake it you can hear the bits bashing around inside. This is done for quietness as the compressor lives in your kitchen. No one has done this in a heat pump or air-conditioning unit for centuries. The motor is hard mounted (welded) into the shell so it doesn't move around at all.

The bottom 1/3 of the compressor shell contains oil, like engine oil in your car, this is used to lubricate the moving parts. If you were to hang the unit upside down........

You wouldn't be the first, the oil would not lubricate the compressor properly and the compressor bearings would fail, fairly quickly. But its ok it would be covered by warranty until the manufacturer saw the install photos.

But if the compressor was just not very level it would have little to no impact on the oil level. In fact compressor come with quite a bit of spare oil in them, reason being the oil mixes with the refrigerant and gets carried around the refrigeration circuit. When they make the unit they have to overfill the compressors to make sure there is enough oil in the compressor body to lubricate when a load of the oil is traveling round the circuit.

So as long as the unit isn't upside down even the compressor doesn't really care if its level or not, I return to the picture at the top. The developers of the kit say its fine.

"Whoa hang on", says the pub expert, "I had a domestic fridge once which we laid on its side and I was told if you put it upright you couldn't turn it back on for 24 hours".

Its actually not bullshit. This is true. The reason is if you lay any refrigeration system on its side the oil can run out of the discharge, or outlet pipe of the compressor working its way into the refrigerant system. If left long enough all the oil ends up in the pipework.

When you get home put it upright and plug it in, the compressor starts and there is no oil in the crankcase so it runs dry. The oil has to go all the way round the system before it gets back to lubricate the compressor. This can take a few minutes by which time the compressor is ruined.

So 2 things to take from this:

Don't lay a fridge / heat pup /air conditioning on its side, but if you do put it upright for a few hours before starting it up. And yes that is a man on a push bike with a fridge on his shoulder, google it, its amazing.

And

Getting the unit level looks nice, but it isn't essential and it doesn't harm the unit.