Heating and Cooling for the Next House - Solar - PV - Heat Pumps - AC

bhjm

Hi all,

I hope you all can share your wisdom and help me to steer in the correct direction. I am not native in English - so any grammatical error spelling mistake may be intentionally ;-P

Situation: I am buying a House for long term stay pot. 20+ years.
- House build 2008-2009
- apparently first Boiler
- 3 storey
- 4 Bedroom
- mid terraced
- garage detached to the house
- nearly all day at home 3-days during the week (working from Home)
- family of 4 (2 kids)

wish list - or we can call it possible options - I am open to most things around heating and cooling.

- Solar Thermal (water heating)
- solar thermal (house heating) - I consider this a very unlikely option.
- PV
- PV with Storage (Battery)
- AC (at least 1st and 2nd floor)
- any kind of Heat pumps. I understood that there are different types?
- infrared heating

below is the house and the Garage. House an Garage are facing South East as below. the spaces in the middle are the approx surfaces to be owned.

what are you thoughts on it?
- heating the water with Solar 
- heating the water with PV and then using the electricity?
- would a combination of PV & Infrared heating 
- currently I am hooked up on the Idea to put Solar on the House and the PV on the Garage
- I used to grow up with solar heated water in summer and winter

Any questions? please fire away.

Thanks !

paul991

think you would be better off maxing your solar pv ,no solar thermal and a electric water heater

Screwdriva

Looks likely that you will be able to install between 8-12 panels on that SE roof aspect. I recommend trying to fit the max # of panels at the highest Watt rating (eg. 550W). 

Forget about Solar hot water, infrared etc. Since you mentioned cooling, I would focus on Air to Air heat pump multi split units and a built Heat Pump Hot Water cylinder like the Mixergy iHp.  

You will need a battery and up to date insulation but once set up, you will be able to heat your home at a SCOP of ~4+ and your hot water at a SCOP of ~3.5, which will save you a considerable amount. 

Martyn1981

Same thoughts from me. Forget the solar thermal, it's no longer competitive with PV, and leccy (electricity) generation can be used to heat water if you need it.

Definitely max out the PV, but can you get power from the garage to your house, as they aren't physically attatched? Maybe you have a power cable (lights, socket etc), but could make PV tricky.

Being mid terrace, your heating needs should be much less, and hopefully the walls are well insulated. You can improve the loft if necessary. So, got to be heat pumps, at least I think so. ASHP connected to the current 'wet system' may be fine, but A2A as Screwdriva mentions, could be a goer, and then you get your AC too if needed.

You could also consider a 'hybrid system', a route I'm leaning towards. So keep the boiler for now, try to reduce gas consumption by installing the A2A units, and if that works well, which it has for us, then stage 2 .....

..... replace the old combi boiler with a much smaller gas boiler for heating, and then add a HPWH (heat pump water heater) (again as suggested). Also possibly add another A2A unit, depending on planning rules.

bhjm

Screwdriva said:

Looks likely that you will be able to install between 8-12 panels on that SE roof aspect. I recommend trying to fit the max # of panels at the highest Watt rating (eg. 550W). 

Forget about Solar hot water, infrared etc. Since you mentioned cooling, I would focus on Air to Air heat pump multi split units and a built Heat Pump Hot Water cylinder like the Mixergy iHp.  

You will need a battery and up to date insulation but once set up, you will be able to heat your home at a SCOP of ~4+ and your hot water at a SCOP of ~3.5, which will save you a considerable amount. 

thanks for your comment. What is SCOP?

bhjm

`Martyn1981 said:

Same thoughts from me. Forget the solar thermal, it's no longer competitive with PV, and leccy (electricity) generation can be used to heat water if you need it.

Definitely max out the PV, but can you get power from the garage to your house, as they aren't physically attatched? Maybe you have a power cable (lights, socket etc), but could make PV tricky.

Being mid terrace, your heating needs should be much less, and hopefully the walls are well insulated. You can improve the loft if necessary. So, got to be heat pumps, at least I think so. ASHP connected to the current 'wet system' may be fine, but A2A as Screwdriva mentions, could be a goer, and then you get your AC too if needed.

You could also consider a 'hybrid system', a route I'm leaning towards. So keep the boiler for now, try to reduce gas consumption by installing the A2A units, and if that works well, which it has for us, then stage 2 .....

..... replace the old combi boiler with a much smaller gas boiler for heating, and then add a HPWH (heat pump water heater) (again as suggested). Also possibly add another A2A unit, depending on planning rules.

thanks a lot !

has PV become much more efficient in recent years?

Garage and House arent physically attached correct. And there is currently NO electrical connection to the garage. There is a pathway from the garden to the Garage - I was thinking to have a connection put in regardless of PV etc for an electric car to be charged in front of the Garage and to have electricity in the garage too. Would this change something? I hope :-)

Walls - taking this from the EPC. Wall Cavity wall, as built, insulated (assumed) below is the rating from the EPC. Do these number add up? What do you think?

what is ASHP & A2A? - sorry these abbreviations confuse me.

what is stage 2 you are mentioning?

regarding planning rules, is there currently in place etc? or would this somewhere in the deed mentioned?

So let`s take Solar Thermal of the list. We are left with the following.

- AC  (is this the Air to Air) unit / split units you are referring to?
- PV with or without battery
- downgrading the Water Boiler

Jonboy1889

Screwdriva said:

Looks likely that you will be able to install between 8-12 panels on that SE roof aspect. I recommend trying to fit the max # of panels at the highest Watt rating (eg. 550W). 

Forget about Solar hot water, infrared etc. Since you mentioned cooling, I would focus on Air to Air heat pump multi split units and a built Heat Pump Hot Water cylinder like the Mixergy iHp.  

You will need a battery and up to date insulation but once set up, you will be able to heat your home at a SCOP of ~4+ and your hot water at a SCOP of ~3.5, which will save you a considerable amount. 

Am I right in thinking that more powerful panels are basically just bigger? At a similar ratio? Ie a 400W panel is effectively c75% the size of a 550w? So per square meter you don’t get much more power? It’s better to configure panels based on what you can fit rather than going for the max size? Ie you might be able to fit more smaller panels meaning higher KW overall than less larger ones given a limited space.

Screwdriva

Jonboy1889 said:

Am I right in thinking that more powerful panels are basically just bigger? At a similar ratio? Ie a 400W panel is effectively c75% the size of a 550w? So per square meter you don’t get much more power? It’s better to configure panels based on what you can fit rather than going for the max size? Ie you might be able to fit more smaller panels meaning higher KW overall than less larger ones given a limited space.

Spot on. In some installations, clever installers can fit a similar # of 550W panels, which are primarily 55cm longer/taller but not wider. This is when the total generation really shoots up!

Waywardmike

Bear in mind that 550W panels being significantly larger are also significantly heavier.

Residential installers may not have the necessary equipment or even desire to hoist them 2+ floors onto your roof.

Martyn1981

bhjm said:

`Martyn1981 said:

Same thoughts from me. Forget the solar thermal, it's no longer competitive with PV, and leccy (electricity) generation can be used to heat water if you need it.

Definitely max out the PV, but can you get power from the garage to your house, as they aren't physically attatched? Maybe you have a power cable (lights, socket etc), but could make PV tricky.

Being mid terrace, your heating needs should be much less, and hopefully the walls are well insulated. You can improve the loft if necessary. So, got to be heat pumps, at least I think so. ASHP connected to the current 'wet system' may be fine, but A2A as Screwdriva mentions, could be a goer, and then you get your AC too if needed.

You could also consider a 'hybrid system', a route I'm leaning towards. So keep the boiler for now, try to reduce gas consumption by installing the A2A units, and if that works well, which it has for us, then stage 2 .....

..... replace the old combi boiler with a much smaller gas boiler for heating, and then add a HPWH (heat pump water heater) (again as suggested). Also possibly add another A2A unit, depending on planning rules.

thanks a lot !

has PV become much more efficient in recent years?

Garage and House arent physically attached correct. And there is currently NO electrical connection to the garage. There is a pathway from the garden to the Garage - I was thinking to have a connection put in regardless of PV etc for an electric car to be charged in front of the Garage and to have electricity in the garage too. Would this change something? I hope :-)

Walls - taking this from the EPC. Wall Cavity wall, as built, insulated (assumed) below is the rating from the EPC. Do these number add up? What do you think?

what is ASHP & A2A? - sorry these abbreviations confuse me.

what is stage 2 you are mentioning?

regarding planning rules, is there currently in place etc? or would this somewhere in the deed mentioned?

So let`s take Solar Thermal of the list. We are left with the following.

- AC  (is this the Air to Air) unit / split units you are referring to?
- PV with or without battery
- downgrading the Water Boiler

Hiya, sorry for throwing so much at you, and all the abreviations, I'll run through your points in order, and also try to include as many abbreviations I can think of, that you may come across whilst chatting on here. Hope I'm, not being patronising, as your english skills are excellent, but many terms will reflect common British slang so I'll deliberately throw in as many as I can think of:

First, yes, PV has become more efficient. My 2011/12 installs are around 15% efficient, now you'll be getting 20(ish)% panels. And whilst that's 'only' a 5% increase from 15-20%, it's a 33% increase in output/generation. For physical size, my older 235Wp and 250Wp panels would now be equivalent to panels in the range of 350-370Wp (and rising). Also costs have fallen over the last decade, hence why solar thermal has fallen out of favour.

[The rating is power output at peak (p), since performance varies not just by sunshine, angle and clearness of sky, but also air temp and wind, which affect the panel temp and output).

Second, the garage. Assuming you are allowed to run a cable (have some sort of rights), then that's a good idea. You might consider a small consumer unit (CU) in the garage, and you could have a separate PV system that feeds back into that CU, and then back down to the house. It may be possible to connect the garage and house panels together, but that will involve a long DC (direct current) cable run, which may be too much trouble. If you think the garage roof is worth considering, then I'd suggest making sure the planned cabling is large enough and takes account of your plans. Nothing serious here to consider, just best to build it with the necessary capability. In fact ..... leaping ahead now, if you want to get a BEV (battery electric vehicle) in the future, then you may want to consider a meaty power cable from house to garage, capable of 7kW+.

Thirdly, walls, I'd assume from the age of the property that it has insulated walls (front and back), and that's a good EPC rating. I'd also assume that the loft is 'well' insulated, but since 2008/2009, recommendations keep rising, so probably worth checking how much insulation there is, and topping up. This is one of the simplest and cheapest ways to reduce heat loss.

Fourthly, ASHP and A2A. The most commonly referred to heat pumps are air source heat pumps (there's also ground source and water source). So that's a large unit outside that provides hot water for your 'wet' heating system and a tank of hot water for washing etc (DHW - domestic hot water). A wet system is one that uses water, typically feeding radiators (you'll see the abbreviation 'rads' used a lot) and/or underfloor heating. As you say the property has a boiler, then that will be GCH (gas central heating), using rads.

A2A is air to air heat pumps, or often called air con. The modern units can operate as heat or cold. So some of us have installed one or two, and use excess generation from the PV panels to help heat the house when heating needs are lower - typically we refer to these as the 'shoulder months', perhaps Mch and April and September and October. But PV and A2A may be able to top up heating in colder months, on sunny days.

Lastly, stage 2. Sorry for the confusion, I meant that for myself, stage one is the rollout of two A2A units, which has helped reduce our gas consumption. And I'm considering (and you may want to think about it), stage two, which instead of replacing the GCH system with a full ASHP (as it's tricky for our house), to further reduce our gas consumption by replacing the current boiler which heats the rads and DHW, with a much smaller boiler*, that only heats the rads. I would then add a HWHP tank (a hot water heat pump tank) that provides the DHW from electricity (leccy). And also, possibly, add a third A2A unit.

*Much smaller boiler, as ours was installed nearly 25yrs ago, and since then we've managed to massively improve the house, and reduce heating needs. Then reduced GCH needs further with the A2A units.

Oops, almost forgot your planning question. I mentioned planning as you will need PP (planning permission) if the ASHP outside unit is within 1m of your boundary (3m in Wales). You also need PP for the A2A units (apparently  ).

Screwdriva

Waywardmike said:

Bear in mind that 550W panels being significantly larger are also significantly heavier.

Residential installers may not have the necessary equipment or even desire to hoist them 2+ floors onto your roof.

I'm not sure what you meant by significantly but I'm aware that the difference is < 6 kgs between a 550W and 410W panel from the same brand. This should be a non-issue for any installer.