The information that has been shared with you is really very useful. It is interesting to learn from the experience of other people, From my experience I would say it's really important to have a good ac system in your house, at the beginning I've thought it does not make much sense to use an expensive one because there is no much science to do, it's just an ac system that blow's you air in your house or blows it out, but I've made the biggest mistake in my renovation process, the ac system could not manage the air volume I've needed and there was a much higher temperature in my house, I was sweating all day and all night, I had to call some local contractors [url=https://www.livesg.com.au/air-conditioning/brisbane/][color=#000000]LIVESG[/color][/url] if I remember it right. I had to pay for a new Ac system but it worths every penny.

Hi

That is a very interesting post.

I am afraid there is a lot of nonsense talked by plumber, PV panel installers and just about anyone involved. they just don't understand the physics of what they are trying to achieve. And nobody at all, wants to understand the potential of Solar Thermal in this country.

[u][b]There are a few things that could do with being unpack in this that I don't think are quite true.[/b][/u]

Firstly that a heat pump increases the energy yield by up to about 3 time. So whereas an infrared heater will take in 1kW of electricity and output 1kW of heat and heat pump will take in 1kW of electricity an emit about 3kW of heat.

Secondly the microwave boiler thing makes no sense to anyone in the industry that I have spoken to. Again it is just a different way of turning energy into heat. It will take in 1kW of electricity and output 1kW of heat. So the only gain that you have over a heating element is that there is nothing touching the water. So nobody can explain how the physics of the thing are better.

Thirdly 1.2kW of solar is well worth doing. If you work really hard you will get the vampire load / base load of terrace house down to about 400w so most of the day you would be exporting or storing 800W of electricity.

Fourthly modern standard plaster board is NOT insulated. I am afraid your builder was pulling your leg. However, I do think you are right that going crazy on wall insulation doesn't achieve a huge amount contrary to what the EPC brigade will tell you. But if were were re-boarding external walls we would use some degree of insulation by default even if building regs don't require it. 

Fifthly most radiator charts massively oversize the radiators.

I don't understand why there was a conversation about using a heat pump with a thermal store? It isn't an absolute requirement. I don't have one.


[u][b]Things that are pretty essential in my experience[/b][/u]

Insulate as much as you can.

Install really good windows - there are windows and there are windows. Some of the 1980's double glazed windows really are not that good at all and should be replaced. It is particularly things like the coatings on the glass and the seals that have really moved on.

If you possible can, use UFH - it is massively more efficient with either gas or heat pumps or solar.

If you do have a small area for solar panels it is worth thinking about solar thermal as opposed to solar PV as it has a much higher energy density. But this does need a thermal store cylinder. However, the cylinders can be quite tall and thin so they don't necessarily take up that much footprint. 

A proper control system that controls all the individual radiators on a time/temperature basis is essential. That way you can turn bedrooms down in the day, have the kids rooms coming warmer earlier and fade out the heating in the living spaces and kitchen in the evenings as the spaces go out of use. Don't forget to aggressively control corridor temperatures as well at night. I tend to prefer not to turn radiators or UFH totally off but to set the temperature to drop to 16C: that way there isn't a condensation issue to contend with. The other side of it is that if you let a big zone go right down in temperature it takes a massive boost of energy to heat it back up which may be hard on a sensibly sized heat pump system. So it is essential to think about the load on the heat pump and when a zone starts to heat to turn something else off to balance that.

Heat pumps alone are not a terribly good solution. My preference is to use them in a hybrid heat pump/gas/solar thermal setup. For the vast majority of the time a relatively small 6kW heat pump heats my house just fine so it massively reduces the carbon footprint: most of the time the gas boiler does nothing. But I do also have a small 24kW gas boiler - it is about half the size the most plumbers would insist was needed. It is a real world solution that reduces my gas consumption by about 80% but I still have the ability to heat things up fast. The gas boiler simply sits downstream of the heat pump and is set for an output temperature of 55C and if the heat pump alone achieves that then the boiler doesn't come on.

Coupled with a decent area of PV solar panels on the roof. Most of the day time this setup is running zero emission as it only needs 2kW of electricity which the panels massively exceed even on a dull day. I have not bothered with battery storage, as it is not particularly good value, or a thermal store. It is a matter of being pragmatic and looking for ideal retrofit solutions isn't terribly realistic. I honestly don't think 100% heat pump is the solution for a terraced house. That is unless electricity prices in the UK drop substantially.

The other solution that works well, if you don't mind a blown air system, is to use a ducted air condition system such as the Daikin Eazyzone System. Air -> Air heat pumps are inherently more efficient that Air -> Water heat pumps at the usual range of London temperatures. It is all down to Delta T which is the temperature difference  that the heat pump is over coming. Based on an external temperature of 5C and a room temp of 21C:-

Air -> Air  about 15C
Air -> Water about 50C
Ground -> Water about 43C 

So air -> air heat pumps win that competition hands down. The main advantage with ground source is when it gets really, really cold and also that as there is no external fan they are quieter.


 

That is so helpful thank you.
We aren’t looking to do as extensive work ad you but your experience is really interesting.
Let me see if I can work out how to message you directly then I can email you direct.
Thanks once again for your reply

hi,

Happy to share - but more a case of frustration I'm afraid. Your circumstances may differ.

[b]Solar panels[/b] - reached out to Wandsworth Council and 2 suppliers. 
- Need planning permission due to conservation area article 4 restrictions - approx £1.2k! And you can pay for pre-advice. Not sure how this aligns with Wandsworth's net-zero pledge!?
- Both solar providers said it wasn't worth doing because we can't use the front roof due to Planning regs and the 4 panels we could fit on the flat roof weren't worth doing.
- Deesolar and EHC were recommended to me.
https://www.deegesolar.co.uk
https://echgroup.co.uk

[b]Ground source heatpump[/b]
- Like many houses in the area we have Thames Water pipes running underground through the back garden, so that was a no. You need a fair amount of ground space and room for a hot water tank.

[b]Air source heat pump[/b]
- Requires larger radiatiors and a hot water tank. We did the math, but don't have the bare wall space.

[b]Infrared[/b]
- Again requires larger radiators and are better position on the ceiling. As we were lowering the ceiling height this wasn't an option. I actually bought a smaller stand alone infrared heater from Herschel and I like it! However there is v little infrastructure on this in the UK. I did find a centre in Swindon with eco retrofit advice including infrared, but didn't get that far out of town.
https://www.herschel-infrared.co.uk
https://www.nsbrc.co.uk/whats-on/our-workshops/eco-workshop/

[b]Internal wall insulation[/b]
- Is really expensive and because it means you lose square footage my suspicion is that it reduces the value of your property. We insulated the new loft and some external walls, but mostly this was in line with building regs. Our builder didn't think the Spacetherm was worth it because standard plaster board is now insulating.

[b]Floor insulation[/b]
- Fitting thermal insulation under the wood flooring has made a signficant difference and is very noticeable on the ground floor (no underfloor heating)
https://naturalwoodfloor.co.uk/product/accessories/underlay-floor-protection/technics-6-underlay-15-07m2-per-roll-34db/

[b]Materials[/b]
- We didn't go with the Haro flooring because there were issues with availability. However we did use a cork tile on the kitchen walls for sound and heat insulation, which worked really well and looks gorgeous.

https://puretreecork.com/product/33408
https://www.amorimwise.co.uk/products/cork/inspire-700/fashionable-antique-white-1

These people might be worth getting in touch with:
https://retrofitworks.co.uk

Good luck! Will be interested to know how you get on. 

Wishing those microwave boilers would come onto the market soon!





 

Hi - sorry you didn’t get any replies to your post last October. I’m looking to do a similar project with a Victorian house. I wondered if you’d be happy to share any more about your experience. Thanks very much.

hi,

We are starting a house refurb in Jan (loft conversion, new kitchen, windows, flooring) and we're keen to do what we can to make it energy efficient, low carbon, and to use sustainable materials.

One option we're looking at is [b]infrared heating[/b]. It seems more popular in Europe than here. I'd be interested to know if anyone has any experience of either panels or wall films, such as this:

https://nexgenheating.com

We looked at an air source heat pump but don't have space for a water tank.

We're insulating where we can but do not have the space to loose to internal wall insulation throughout the house. We like the option of using [b]Spacetherm[/b] wall board instead of plaster board. Again is anyone has experience wit this, I'd love to know.

https://www.proctorgroup.com/projects/spacetherm-wallboard-bristol

For flooring, we're looking to use a Haro cork composite which looks great, and is sustainable, but again quite an unknown in terms of durability.

https://www.wood2u.co.uk/haro-cork-floor-corkett-arteo-xl-oak-portland-invisible-brushed-permadur-finish-537263-cork-flooring.html

I'd love to hear from anyone who has worked on a similar project, I don't really have budget for professional advice. The price has already gone up a lot, due to Brexit!


Thanks!