Be careful what you measure.

Finally I've finished project impossible. The job where I installed an 8 year old, low temperature air source heat pump straight onto a 51 year old heating system in a badly insulated 1930s semi, without changing any rads or any pipe work. The aim was to prove its not very hard to install heat pumps Afterall.

Last weekend we fired it up for the first time. Now anyone can try a crazy experiment like this but it would be much better if we measured the performance of the system and see how it all works using online heat and electric meters.

I was extremely lucky with this as Marko Cosic helped me by providing me with 4 heat meters and an M Bus electric meter to measure everything during the trail.

To start with we measured the old gas boiler and hot water cylinder, the performance was predictably appalling, you can see the figures from my blog a few weeks ago. Once the heat pump was ready we re tubed the same meters and set them up as follows:

Meter 1 is in the main flow out of the heat pump, using a 28mm diameter meter with wireless comms. We also have a 22mm meter across the Sunamp measuring what heat goes into it from the heat pump. We have one across the output of the Sunamp to see what comes out and another one across the Showersave - Waste Water Heat Recovery more on these as we get the figures.

So using a little arithmetic we can work out where the heat is going and how well each bit works. IF you are a cop geek we can give you this info but all we are interested in is how much money does it cost to run.

The heat meters are bloody amazing, you get a meter which any fool can cut into the pipework using standard compression fittings, if you can fit a valve you can fit the meter. Look at this below. they even come with fibre washers.

Next you have a sensor pocket which looks like a 22mm ball valve with a hole in it. Using an o ring provided you screw in the sensor and that's it. If you are an idiot (I was) and the meter sensors are the wrong way round you can swap them in a few seconds.

Once the meters are in you tell Marko what serial number meter does what, its easy the number is on the front of the meter and then it starts counting.

And then the genius bit happens.

Marko sends you a magic box, you plug it in the mains and that's it. Some how the meters know its there adn tlak to it, it then talks to Marko and it ends up on the internet. I have literally no idea how this works but I dont care, it just does. Its perfect for idiots who dont know who an Ip address is.

The last bit is to wire in the electric meters, these go in the distribution board just like an MCB. the only extra is you have to run a 2 core cable from the meter back to Markos magic box, the meters are not wireless, yet.

Once wired in, (the sparky doesn't even have to get the wires the right way round, it sorts that out too). Marko can see energy in.

So in brief we now know power into heat pump,

Heat saved by shower save

Heat into Sunamp

Heat out of Sunamp

Heat out of the heat pump

and finally heat into the house.

All figures will be published for anyone to see. But spoiler alert cop is 3.8 for the last 2 weeks. Not bad for an old unit running old rads, on old pipework.

In summer we will install a new high temp heat pump and might change the odd rad, but if we do we will measure the progress and publish it. There is no guessing or speculation on this job.

I'm keen to prove that Heat pumps are actually really simple when you know how, (all you have to do is get the air out). They are and always have been just boilers that live in the garden.