Jump to content

Bunsen Air Heat Pump for domestic hot water


Recommended Posts

Looks like the Spanish/Portuguese imported direct system have risen above the parapet again................

 

Last time a couple of companies tried importing these, they got into hot water with the MCS, and had they approval withdrawn.  In essence, they are just an ASHP, with no fan on the external evaporator, and with that evaporator formed as a flat plate, rather than an air-blown finned array.  The interesting thing is that a lot were sold in Ireland a few years ago, and the owners were pleased with them.  I wanted to fit a double panel unit as our hot water system, with the panels mounted on the East wall.  I went down to Southampton to see the importer, who had a demo system running, and it was pretty impressive looking.  The really big show stopper is that there was zero technical data.  Not even the manufacturer (in Portugal) could provide really basic info on COP.  In theory, the efficiency should be higher at high DHW temperatures, because of the direct exchange between the refrigerant and the DHW, but the manufacturers were really cagey about letting me have any data.

 

In the end, the two companies I spoke with both dropped the product, and refused to supply it to the UK market, just because they couldn't get data from the manufacturer.  This was the last email I had about these "thermodynamic" systems, back in March 2013:

 

Quote

Jeremy.

 

Many thanks for your enquiry.  Unfortunately I am unable to answer your COP questions as the data cannot be reliably sought from the manufacturer.  The system looks very good on paper however over the past 12 months we have lost confidence in the product.  It has also been removed from the MCS list of approved products which further demonstrates a lack of positive performance data.  Therefore we have made a decision not to support this product.

 

Edited by JSHarris
  • Like 2
Link to comment
Share on other sites

I've been digging around and have found the independent test data from just after I'd decided to not go with these: http://www.narecde.co.uk/thermodynamic-panel-data/

 

Look carefully at the Coefficient of Performance (COP) data points.  The performance seemed worse than an immersion heater at times (COP less than unity) and even on good days the COP seems to have struggled to get much above 2, which is pretty dire, and far worse than I would have expected.  Our ASHP rarely drops below a COP of 3, but then it doesn't deliver water at such a high temperature.

Link to comment
Share on other sites

  • 5 months later...

I have had a Bunsen Air on my house for 2 months now and we are delighted with it. Switched the oil off to the hot water and the Bunsen does it all. It was set to Energy Saving, so we have 3 different temps each day which has worked perfectly so far.

 

Most of the heating is done in the day when our Solar PV covers all the running costs.

Many thanks to the Light Group for installing it for us, the system is great, the team were great and altogether we couldn’t fault them!

 

 

Link to comment
Share on other sites

27 minutes ago, Dhends said:

I have had a Bunsen Air on my house for 2 months now and we are delighted with it. Switched the oil off to the hot water and the Bunsen does it all. It was set to Energy Saving, so we have 3 different temps each day which has worked perfectly so far.

 

Most of the heating is done in the day when our Solar PV covers all the running costs.

Many thanks to the Light Group for installing it for us, the system is great, the team were great and altogether we couldn’t fault them!

 

 

 

Welcome.

 

Can you give any more info, like the measured and certificated COP under standard conditions (it will be on the paperwork), as I spent a lot of time looking into this product but failed to get any real data on performance. 

Link to comment
Share on other sites

I like the idea of them as they can be easy to install, and for very small house like mine, may be helpful. (This is not an invitation for LHG to contact me).

But I have always questioned the long term reliability of them and the performance in the UK.

I shall have a word with a Portuguese woman I know whose son works in the RE industry (wind turbines I think).  He may know something.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...