The most efficient portable Aircon - the Delonghi PACEX100

Screwdriva

After alot of research, we found the Delonghi Pinguino PAX100 consumes a max of 630Watts (measured) to provide 10000 BTUs of cooling. While portables are inherently inefficient in their design, especially single hose systems, I could not find another portable that comes close to this one in terms of cooling for the cost. 

Despite current electricity prices, we have been paying 30p for a full night's cooling. Daytime use ensures the PV system can cope with the input draw till the early evening. We purchased ours a few months ago on ebay for around £500 where a few examples are available. Thought I'd share incase anyone can't justify splurging for the full heat pump solution but needs to stay cool. 

Reed_Richards

10000 BTUs is 2.93 kWh.  You can't have Watts producing kWh; did you mean that 0.63 kWh of electricity removes 2.93 kWh of heat?  That would be a CoP of a bit less than 5.

QrizB

Reed_Richards said:

10000 BTUs is 2.93 kWh.  You can't have Watts producing kWh; did you mean that 0.63 kWh of electricity removes 2.93 kWh of heat?  That would be a CoP of a bit less than 5.

A "10000BTU a/c unit" produces 10000BTU/hr of cooling. It's a crazy way to measure them but it's what everyone uses.

And yes, that's notionally a COP of about 5.

Although the ErP label claims an energy input of 0.7kW for 2.5kW of cooling and an EER of 3.6.

I keep looking at portable split units (like this example, not a recommendation) but the price always puts me off.

Screwdriva

QrizB said:

I keep looking at portable split units (like this example, not a recommendation) but the price always puts me off.

We found this DeLonghi for sale last Autumn for £510 with a  4 year warranty included and jumped at it.

Reed_Richards

QrizB said:

Reed_Richards said:

10000 BTUs is 2.93 kWh.  You can't have Watts producing kWh; did you mean that 0.63 kWh of electricity removes 2.93 kWh of heat?  That would be a CoP of a bit less than 5.

A "10000BTU a/c unit" produces 10000BTU/hr of cooling. It's a crazy way to measure them but it's what everyone uses.

And yes, that's notionally a COP of about 5.

Although the ErP label claims an energy input of 0.7kW for 2.5kW of cooling and an EER of 3.6.

I keep looking at portable split units (like this example, not a recommendation) but the price always puts me off.

So a "10000 BTU a/c unit" means a 10000BTU/hr a/c unit or a 2.93 kW (of cooling) a/c unit.  But the label  says 2.5 kW so the 10000 BTU/hr capacity is somewhat nominal.  And the 0.7 kWh/60min on the label means 0.7kW (possibly as an average).  It's completely crazy.

People on this forum can get criticised for confusing kW and kWh and here are a/c vendors making exactly the equivalent mistake. 

ispookie666

Used to have AEG chilflex, very efficient and low running cost (not as cheap as split). But boy the noise was a bummer.  Sold it after 8 months 

2nd_time_buyer

We have an AEG Chillflex. It is the 9000 BTU version which also has a heat pump: AXP26U558HW.

It is quieter than the Delonghi Pinguino PAX100 (61dBA versus 64dBA sound power level). It is not quite as efficient at cooling (3.1 versus 3.6 EER). But unlike the Delonghi is also a heat pump with A*** efficiency (4.6 COP).

When testing the efficiency for portable AC units they don't fully include two big factors:

1) heat gain to room from the hot ventilation pipe

2) drawing cold outside air into the house

In heat pump mode you get the same inefficncies in reverse. The first point can be fairly easily mitigated by using insulated ducting. The second point can be the more significant and make a bigger dent in efficiency. In cooling mode where you have a 10 degrees difference between the inside and outside temperature (e.g. 22 versus 32 degree), this can equate to a 30 drop in efficiency when considering the house as a whole.

In heat pump mode the effect can be even more dramatic in colder temperatures where the inside/outside temperature difference can be upwards of 20 degrees. In this case the whole house efficiency can even be negative.

We use ours in a fairly specific way as it is used in our home office in the loft. Effectively it sucks all the heat from the house up into the loft during the day when the rest of the house is empty. With headphones on it is inaudible. The cooling is a secondary bonus but is more than sufficient when needed.

Overall we are pleased, partly because we only paid £180 for it secondhand. At anything like the RRP I would definitely be swayed towards a split unit.

Screwdriva

That's a nice looking portable! It does consume a couple hundred watts more than the Delonghi but the heating benefit more than makes up for that!

NoobSolar

Extremely grateful to you all for these insights.

Excuse my childish question. You explained that 'Despite current electricity prices, we have been paying 30p for a full night's cooling.' that means your property is drawing approx 1, or 1.1 kWh overnight to get this cost.

That indicates to me that the unit cannot be drawing 630w continuously, because if it was it would be something like. 630wh x 10 = 6.3kwh = 6.3 x 30p typical electricity rate = £1.89.

I assume from this that the unit is not on continuously, but cycles and draws variably?

2nd_time_buyer

NoobSolar said:

I assume from this that the unit is not on continuously, but cycles and draws variably?

Yes, assuming it can get down to the set temperature, it then cycles on and off around it. This is how most (all?) portable ACs operate.

However, most split units now use an inverter, so rather than cycling on and off, they can regulate the output depending how close they are to the set temperature. This is more efficient and also ensures the noise levels are more stable. Another advantage is that the start-up current is lower.

Screwdriva

NoobSolar said:

I assume from this that the unit is not on continuously, but cycles and draws variably?

This is correct and depends primarily on set  temperature and the ambient temperature in the room. One benefit of the lower input needed is that the rooftop solar system can cope with the compressor when the odd cloud or two gets in the way during the day.

Inverter based compressors are an incredible innovation that work really well on appliances that are always on or work for the majority of the year. A heat pump or fridge  as examples. Our Panasonic inverter fridge is going strong 10 years on, having paid for itself in energy savings over a conventional unit. 

The advantages of inverter technology become less clear on an occasional use device like a portable ac used for a few weeks each year. That said, the noise of an ac compressor cycling in and out is completely eliminated.