Discussion ... ASHP(Air/Air) with Solar pv ....
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We've promptly come to the conclusion that life's too short to wait and decided to go ahead with a second unit just as soon as can be arranged.Coastalwatch wrote: »At the outset I'd followed this thread purely to supply additional heating in the spring and autumn just as Zeup had envisaged. I'll see how the ASHP performs in the coming months with perhaps a view to having a second unit installed next year so we too can reduce our FF use even further!
Rather than siting it in our bedroom, as originally thought, our installer suggested the small lobby positioned centrally in the bungalow.
On reflection it's a much better option, not that we spend time in there, but the doors to four rooms open from it. In particular the north facing bathroom which the unit would point directly at and so make nice and toastie. To one side are the two bedrooms and opposite those is the hall door. So, as suggested by the initiator of this thread, it's then merely a case of opening or closing doors to supply heat, or not, to adjoining rooms as deemed necessary. Admittedly that leaves the kitchen and a small ensuite which are unlikely to benefit from heat of either ASHP unit but otherwise we should have the option of heating the entire property by renewable energy. I don't believe we shall do away entirely with burning gas, we also have a gas hob, but should be able to significantly reduce our dependence upon it.
Further to this I've a small stocks and share ISA over which I apparently have no control or influence as to where its contents might be invested. Not now being happy with this, then come the appropriate time, I shall redeem and redirect into the resulting sum into renewables projects where possible.
And to think that less than a year ago we were happily pumping diesel into our Focus and switching the gas central heating on with little or no thought about the world we live in, so quite a transformation.
I blame Mart and Zeup entirely!East coast, lat 51.97. 8.26kw SSE, 23° pitch + 0.59kw WSW vertical. Nissan Leaf plus Zappi charger and 2 x ASHP's. Givenergy 8.2 & 9.5 kWh batts, 2 x 3 kW ac inverters. Indra V2H . CoCharger Host, Interest in Ripple Energy & Abundance.0 -
I am now looking to go down the route of adding an air source heat pump to provide space heating for our living room which is approximately 35 sqm. We have oil c/h and solar panels.
I have one or two questions which some of you might be able to advise on.
I have had the first surveyor out today and he mentioned RHI but I am not sure this will be applicable. Is it not a requirement that an ASHP must use a liquid to provide space heating? Has anyone received RHI for an air to air system?
He advised against wall mounting of the external unit because of vibration but I note that others have not had this problem. Has anyone had a problem with noise transmitted through a cavity wall?
Because of the distance from our distribution board I was keen to take a spur from a ring main - he is going to discuss with his electrician but would have preferrred a dedicated circuit to avoid overloading the ring main. I think we are talking about a 5kwh (output) unit. Thoughts?
What are they like to live with noise-wise in a living room?
Would one be aware of air blowing (drafts)with a unit situated on the wall above a settee?
Now the big one - has anybody calculated the payback period on their unit? In the summer when it is being used for aircon the electricity will most probably be free from our PV but at this time of year we use all our generation, the IBoost mopping up any surplus, so by using the unit we would be displacing other usage. (Does any payback calculation need to take into account maintenance costs?)
Any other advice will be welcomed.
KenNorthern Lincolnshire. 7.8 kWp system, (4.2 kw west facing panels , 3.6 kw east facing), Solis inverters, Solar IBoost water heater, Mitsubishi SRK35ZS-S and SRK20ZS-S Wall Mounted Inverter Heat Pumps, ex Nissan Leaf owner)0 -
Comments added in blue below.I am now looking to go down the route of adding an air source heat pump to provide space heating for our living room which is approximately 35 sqm. We have oil c/h and solar panels.
I have one or two questions which some of you might be able to advise on.
I have had the first surveyor out today and he mentioned RHI but I am not sure this will be applicable. Is it not a requirement that an ASHP must use a liquid to provide space heating? Has anyone received RHI for an air to air system?
As far as I am aware RHI does not apply to an Air to Air Heat Pump/Air Conditioner, but it should qualify for 5% Vat rate.
He advised against wall mounting of the external unit because of vibration but I note that others have not had this problem. Has anyone had a problem with noise transmitted through a cavity wall?
Ours is mounted on the outside of the wall behind our sofa in the lounge and we don't have any fibration problems. The unit is mounted on rubber spacers on the support brackets.
Because of the distance from our distribution board I was keen to take a spur from a ring main - he is going to discuss with his electrician but would have preferrred a dedicated circuit to avoid overloading the ring main. I think we are talking about a 5kwh (output) unit. Thoughts?
Ours in connected to a spur on the ring main. Although the unit may be 5kW output, the input for that is likely to be less than 1.5kW when running on max, as if you get an efficient unit they have a COP of between 3-5 depending on outside temp. Most of the time, ours is only drawing about 200 watts.
What are they like to live with noise-wise in a living room?
With ours there is a slight hum, but it is not intrusive.
Would one be aware of air blowing (drafts)with a unit situated on the wall above a settee?
That's where we have ours situated. In fact we moved the sofa to underneath it, because of warm flow of air from it.
Now the big one - has anybody calculated the payback period on their unit? In the summer when it is being used for aircon the electricity will most probably be free from our PV but at this time of year we use all our generation, the IBoost mopping up any surplus, so by using the unit we would be displacing other usage. (Does any payback calculation need to take into account maintenance costs?)
I estimate the payback period for ours to be about 7-8 years, based on the amount of gas we have saved since its installation. I have been told there is no maintainance required, apart from cleaning the filter of dust every few months. Easily done with a vacumn cleaner. Spring & Autunm are the most efficient times for making best use of available solar power.
Any other advice will be welcomed.
It is great to have during a Summer heatwave. Keeping cool for free.
Ken0 -
Hi Ken and thanks for your interest in the thread, I'm sure others more experienced will assist with their thoughts to your questions.I am now looking to go down the route of adding an air source heat pump to provide space heating for our living room which is approximately 35 sqm. We have oil c/h and solar panels.
Now the big one - has anybody calculated the payback period on their unit? In the summer when it is being used for aircon the electricity will most probably be free from our PV but at this time of year we use all our generation, the IBoost mopping up any surplus, so by using the unit we would be displacing other usage. (Does any payback calculation need to take into account maintenance costs?)
Any other advice will be welcomed.
Ken
With their help I've discovered just how useful and efficient ASHP can be. We've a full modern GSH system so you would think that with gas around 3.5p/kWh against electric around 14p/kWh that it would be a no brainer when it comes to which offers the best value when it comes to heating.
However, as stated earlier in the thread for every kWh of electricity used to power the ASHP anything between 3 and 6 times this value in heat energy is returned. Takes some getting your head around I know, I not sure I have yet, but it is fact.
Just to complicate matters even a modern gas system is not 100% efficient with the boiler being approx 90% so. Added to this will be the losses incurred in the pipework feeding radiators etc plus around 200 Watts of electricity is also required to power the flue fan and circulating pump all the time the system is running(pointed out by our Installer). Multiply this latter figure by those stated earlier, then ASHP would return about one kWh of heat for the leccy alone!
I've no idea what Oil fired heating costs are but suspect it is somewhere between the two. Afraid you'll need to do your own calculations upon this matter but would be surprised if oil worked out to be more cost effective. Plus of course some of your heat will be supplied by solar energy, not to mention a significant reduction in FF pollution.
I'm unsure about qualifying for RHI, although I do know that vat amounted to a 5% addition upon our bill for it's installation.
Our outside unit is mounted on the outside wall above the bedroom and makes less noise/vibration than that of the Gas boiler and pump similarly positioned. The latter being only a gentle intrusion and barely wakes us prior to the alarm when set. As for noise from the internal unit then once up to temperature output noise can be adjusted down to barely audible. As for over loading the ring main then while output maybe 5 kW, input will be significantly less than an electric kettle. Maybe 1500W at start up and considerably less after that. All the same there is merit to having a dedicated circuit for it and if you eventually feel the need for a second unit then it may be useful for this also.
As Zeup suggested earlier in the thread it is perhaps better to go for one of the higher spec versions, triple A rated if poss, over the lower spec units which only operate at one speed. Flat out!
Hope this helps.East coast, lat 51.97. 8.26kw SSE, 23° pitch + 0.59kw WSW vertical. Nissan Leaf plus Zappi charger and 2 x ASHP's. Givenergy 8.2 & 9.5 kWh batts, 2 x 3 kW ac inverters. Indra V2H . CoCharger Host, Interest in Ripple Energy & Abundance.0 -
I'll add my comments in blue (leaving white for any UK fans!) [Edit - make that red!]I am now looking to go down the route of adding an air source heat pump to provide space heating for our living room which is approximately 35 sqm. We have oil c/h and solar panels.
I have one or two questions which some of you might be able to advise on.
I have had the first surveyor out today and he mentioned RHI but I am not sure this will be applicable. Is it not a requirement that an ASHP must use a liquid to provide space heating? Has anyone received RHI for an air to air system?
My understanding is that it has to provide hot water and be the principle source of heating. And at around £1k hardly worth bothering anyway.
He advised against wall mounting of the external unit because of vibration but I note that others have not had this problem. Has anyone had a problem with noise transmitted through a cavity wall?
Ours is on a single wall, but it is the outer pantry wall, not living space, but not noticed any vibration. The mounting brackets do have rubber spacers on them between them and the unit.
Because of the distance from our distribution board I was keen to take a spur from a ring main - he is going to discuss with his electrician but would have preferrred a dedicated circuit to avoid overloading the ring main. I think we are talking about a 5kwh (output) unit. Thoughts?
Our unit came with a long lead and plug, so it just plugged in.
What are they like to live with noise-wise in a living room?
Would one be aware of air blowing (drafts)with a unit situated on the wall above a settee?
Ours is in the conservatory so warms/cools through the adjoining door, but the noise is tiny unless the fan speed is higher than 3 (goes to 6), but even then not too bad. Great for sitting/standing under when you get back in from hot or cold.
Now the big one - has anybody calculated the payback period on their unit? In the summer when it is being used for aircon the electricity will most probably be free from our PV but at this time of year we use all our generation, the IBoost mopping up any surplus, so by using the unit we would be displacing other usage. (Does any payback calculation need to take into account maintenance costs?)
Same as ASB, in fact one of his posts opened my eyes to the increased savings as I was comparing solar powered leccy to gas consumption, but even on dull days (like yesterday) I can use the HP instead of GCH for whole house, so whilst the leccy bill is going up for the living room, and might be more than the gas savings for the living room, I'm also saving gas elsewhere.
Regarding payback - I suspect ours has already managed it as I really don't like being hot for 48hrs+ without a chance to cool down, so the A/C use for over a month this year probably saved me from going insane during 'that' heatwave.
Any other advice will be welcomed.
Not sure about this, can't decide if it's right or wrong, but I went for a cheap unit where I can't reduce output when PV is low. At first I regretted my decision to penny pinch, but then started to think (as per previous comment) that whilst I might import more leccy, it's providing heat at gas prices thanks to the COP, so I save a bit of capital cost, but heat more from import, but get more comparatively well priced heat ....... not sure what's best, but no longer think I made a bad decision, just a choice between two options.
KenMart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW). Two A2A units for cleaner heating.
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
They show as red on my screenMartyn1981 wrote: »I'll add my comments in blue (leaving white for any UK fans!)
NE Derbyshire.4kWp S Facing 17.5deg slope (dormer roof).24kWh of Pylontech batteries with Lux controller BEV : Hyundai Ioniq50 -
They show as red on my screen
Congrats, you passed the test ..... <cough>
Monkey see (blue) monkey say (blue), at least my little monkey brain still managed to choose red.
Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW). Two A2A units for cleaner heating.
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
Hi guys,
I am wondering if anyone would be so kind as to comment on the first quote I have received please. I am particularly interested in your thoughts on cost but if you are familiar with these units and are able to comment on noise levels or efficiency that would be much appreciated.
Supply & Installation of 1 no Mitsubishi HI SRK35 Inverter heat pump wall mounted system £1096
+ 5% VAT
Or
Supply & Installation of 1 no Panasonic CS-FZ35UKE Inverter heat pump wall mounted system £975
+ 5% VAT
External Unit at approximately 3m high on side wall. Power supply from local internal socket with cable clipped externally to outdoor unit position.
Sound pressure levels are quoted as
25 - 33 - 38 dba for the Panasonic unit (L-M-H)
19 - 26 - 30- 40 for the Mitsubishi unit (UL- L - M- H) both internal
Panasonic 3.84 (0.80 - 4.40)kw heating capacity EER/COP n/a
Mitsubishi 4.0 (0.9 -4.8)kw heating capacity EER/COP 3.47/4.00
I am veering towards the Mitsubishi because of its UL option for low noise.
ThanksNorthern Lincolnshire. 7.8 kWp system, (4.2 kw west facing panels , 3.6 kw east facing), Solis inverters, Solar IBoost water heater, Mitsubishi SRK35ZS-S and SRK20ZS-S Wall Mounted Inverter Heat Pumps, ex Nissan Leaf owner)0 -
I don't know enough to comment on models, but the prices are nice. I assume from the names that they are 3.5kW output, and thought I should add that that's what I went for.Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW). Two A2A units for cleaner heating.
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
Hi guys,
I am wondering if anyone would be so kind as to comment on the first quote I have received please. I am particularly interested in your thoughts on cost but if you are familiar with these units and are able to comment on noise levels or efficiency that would be much appreciated.
Supply & Installation of 1 no Mitsubishi HI SRK35 Inverter heat pump wall mounted system £1096
+ 5% VAT
Or
Supply & Installation of 1 no Panasonic CS-FZ35UKE Inverter heat pump wall mounted system £975
+ 5% VAT
External Unit at approximately 3m high on side wall. Power supply from local internal socket with cable clipped externally to outdoor unit position.
Sound pressure levels are quoted as
25 - 33 - 38 dba for the Panasonic unit (L-M-H)
19 - 26 - 30- 40 for the Mitsubishi unit (UL- L - M- H) both internal
Panasonic 3.84 (0.80 - 4.40)kw heating capacity EER/COP n/a
Mitsubishi 4.0 (0.9 -4.8)kw heating capacity EER/COP 3.47/4.00
I am veering towards the Mitsubishi because of its UL option for low noise.
Thanks
Here are some details for the Panasonic models.
https://aircon-online.co.uk/product/wall-mounted-fz-type-standard-inverter-%e2%80%a2-r32-gas/
The COP ratings for both appear to be 25% lower than the Toshiba models Z & we have.0
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