Air to Water heat pump added to solar heating system

[rt29781]

We have added a Trianco Air to Water heat pump to our Solar heating system.  The Trianco just requires connecting to a power source and the underfloor loop. I have added a PVC heat exchanger to the tank made from 10cm soil pipe and 40mm water pipe.  This appears to work at this early stage.  We would need 20 m of 28mm copper in a loop to get rid of the maximum 12kW output of this heat pump.  The fact is at low air temperatures the heat pump only puts out about 6kW.
  The heat exchanger was a pig to get leak tight but I got there.  I made it from cheap PVC pipe rather than Copper because of cost.  The Trianco is attached to the heat exchanger and the solar circuit using two 1 metre long 1inch diameter flexible hoses. I ran the system overnight and used our Resol Deltasol M to monitor the heat pumps output into our underfloor system.  The outside temperature was between -2 and -3C.  The underfloor heating was on in three rooms total area 80 m2.  We also have our air to air Mitsubishi system working in the lounge during the day.  See our blog (see footnote) for a graph of last nights output, a picture of the heat exchanger and a diagram of the system.  The pictures are too big to add to the post...tried shrinking them....  Any comments welcome. There has been no solar gain for days.  We are also putting in a woodburner but due to late delivery of the flue that is not in yet.

[EccentricAnomaly]

Any comments welcome.

Looking at this reminds my why I don't normally look at your otherwise quite interesting blog.  Loading a few megabytes of pictures going back to September 2006 just to see the last entry or two is bonkers.

[brackwell]

ref your air/air Mitsubishi. This is the one i have set my heart on  and wondered how you get on with it.  Some would say that air/air is useless when it gets really cold but it seems a much better alternative to changing my gas boiler circa £2000 + which would give me a pay back time of about 20yrs !

Ken

[rt29781]

Hi Brackwell,  The Mitsubishi air to air heat pumps were fitted when we bought the house.  They work great but obviously when it is -3C outside they they don't give much heat.  thye also only heat from the knees up so the floor is freezing which makes you feel colder than you are hence why we have an air to water heat pump.  With the temperaturs you have in the UK at the moment I am not sure they would give you much heat.

Hi Eccentric Anomaly, I spend a very small amount of time posting on the blog, other more pressing jobs.  With fast internet it loads fine and I expect most people have that.  You can't please all of the people all of the time and things could always be better.  If you want the info it's there.  No one forces you to read it and the format will stay the same.  For people wanting to know the history of what we are doing a chronological list is fine.  Positive comments accepted not sure I want to be taught to suck eggs .

[rt29781]

Yesterday we had some sun.  This boosted the underfloor heating and made the 80 m2 we are heating cosy.  Here is a link to the information on our blog:
http://smartfrance.blogspot.com/2010/01/yesterday-we-had-hazy-sunshine-for.html

The link should just load the page of interest rather than the whole blog.  If you want the whole blog the footnote has the link.  I am most impressed that it was so easy to combine the air to water heat pump with the solar heating system.  Previously I had hoped to use a water/water heat pump from Navitron.  However water to water heat pumps are very choosy about the input temperature they can cope with and sometimes the solar output temperature gets to 40C. 

[rt29781]

Yesterday we had some sun.  This boosted the underfloor heating and made the 80 m2 we are heating cosy.  It was so warm the heat pump was not required in the afternoon.  The cop was much improved too as the outsde temperature was 9-10 C.  Here is a link to the information on our blog:
http://smartfrance.blogspot.com/2010/01/yesterday-we-had-clear-skies-and-so.html

The link should just load the page of interest rather than the whole blog.  If you want the whole blog the footnote has the link. 

[dhaslam]

The input temperature is very important for the air to water heat pump for both output  capacity and efficiency.   The electricity used seems to stay much the same  at different input  temperatures.  If you can devise a way to keep the input air temperature over 7C  the output would almost double compared to the input being 10C lower.     I am going to make a fairly elaborate seasonal  heat store but a relatively small underground  pipe loop would do to temporarily store heat if there is sun during the day.         

[rt29781]

Hi DHaslam,

We have an underpool loop of 25mm irrigation piping that returns a temperature of 15C so will hook that up to a pex loop in front of the heat pump and see if that helps.  Not sure how long that can supply heat for but won't cost anything to try. We also have 45 tonnes of water in the swimmiing pool that I can extract the heat from  In winter the pool is at a constant 8-10 C.  The outside air temperature is 13C today and the house is cooking.  All the internal doors are open.  All this for 2.5kW of electricity per hour that costs us nothing because of the electricity we sell back to EDF from the PV.  So I will experiment a bit.  We always planned to use a heat pump and having taken the plunge and bought a Trianco S1200 I am very happy so far. We can use the Resol Deltasol M to control a circulation pump to feed low grade heat to the PEX loop in front of the heat pump.  So it will be a cross between a ground source heat pump and an air source one......  I would rather use a pex loop than a metal heat exchanger as PEX is freeze proof...

Some sun today but mostly cloud,  Even so any solar input is a welcome extra,

[rt29781]

This is yesterdays output with a graph from open office which does recognise the timeline and an explanation of the heat pump performance.

http://smartfrance.blogspot.com/2010/01/this-is-output-from-solarheat-pump.html