All our work will be Code 3 and houses are easier to hit than flats, has anybody done any Code 3 flats and what route did you take?

Solar panels, PV or MVHR?

It is almost impossible to get to 3 for a mid block flat -- this is a failing of the code so I would appeal to common sense and hope to win

A flat with one outside wall will always be very economical on heating for instance so improving the insulation to that wall though valuable does not get near enough.

Paul T. Your doing it all wrong.
Your approach is fine for Housing association flats but not great for owner occupiers. Nobody want to be part of a development where you are not in control of the bills. Even with heat meters fitted you still have a shared service charge for the boiler plant, etc. What end users want is conventional heating with control over the bills.
Try putting indivdual solar solutions or PV on flats!

There is a good solution that provides the answer. You need exhaust heat pumps. These use the waste heat from a central extract system to drive the heatpump. They have excellent COP and when run through the SAP programme give an excellent score. There is no need for bolt on renewables if you go this route. The occupier gets underfloor heating of radiators and is is total control of bills and temperature in the flat. Try the NIBE website for details. We have designed as couple of these schemes for sites in the North West

Hi delboy , I have worked out the costs - I do it daily for a living and I can assure that any sensible occupant would want low cost heating as apposed to their own expensive system.; As you say there are always service charges in place anyway.

Freedom Costs.

timeevans2000 I did not post to debate, just to inform from my actual experience of working on Code level 3 (and higher) flats- I have to say your approach is wrong by the simple fact that you have promoted a energy concentrating product rather than looking at a holistic solution. HRV systems come into play because they are the only system (as recognised by UK authorities and Passiv Haus) that reduce heat loss rather than trying to generate heat from other sources.

Heat pumps do not generate low cost, low carbon hot water - the only people who think so are using manufacturers data.

At the present time in the UK there is no heat pump (of any type - air source/exhaust air/ground source/water source) that can generate a COP of higher than 2.5 or 3.2 for domestic buildings; This is a clear statement in the SAP 2005 document (2008 revision) which is legally binding for use in SAP - SAP software that allows manufacturers claims is not compliant. - Please note this assessors who are entering inflated values - they are wrong.

(I should say that I do use heat pumps, but only in specific circumstances with a full knowledge of what they realy do).


What is wrong with housing association flats sharing a common low carbon/low cost heating solution and also providing the benefits to more of us? The English housing survey found that the type of occupant most likely to suffer from fuel poverty (and related deaths/illnesses) was living in a privately rented top floor flat in a pre 1984 conversion using electric storage heaters (and an immersion heater for hot water).

Looking forwards the housing association occupants have a far safer future regarding energy costs than those free to chose high cost alternatives.

delboy - I have looked at pv on flats for CfSH (we are assessors) and found:
1) The surface area is huge
2) The cost is huge


CIS in Manchester have clad their walls in pv - for new flat this should not be a huge marginal cost if it si used as part of an integral weather shield
There are balcony Solar HW systems (small evacuated tubes)

Peter,

You say the NIBE unit (the MVHR part) is not in SAP Appendix Q yet which means you can't claim MVHR credit in SAP. Is it not that you simply assume the default MVHR SFP and heat recovery efficiency? Therefore you can model it as a MVHR system in SAP, it's just that it will be an inefficient (default) one?

Olly

I've had this problem with MVHR units ( including a NIBE) and took it too NHER, after a couple of days they came back to me and said it was right despite the huge rise in DER but couldn't really explain why it was such a large rise other than well it's a big house. I now have to advise clients who are installing these more and more that they need to pick one off the Appendix Q even though they might not be the best ones - it's very annoying.

Well that got the debate going!!
Most Nibe heat pumps go into housing association flats. The technology is fridge type technology. Its a compressor. These have been around for ever. Hardly rocket science. The 8kw immersion heater is selectable. It can be inhibited to limit is to what ever you want. 2kw is a normal setting for flats. The use of this immersion heater is very infrequent. Usually when the property has been unoccupied for some time where no flat is cold.
As far as COPS are concerned I do not disagree, but remember that these use exhaust air as the heat source. Typical loads in flats are less than 5kw due to good air tightness and good thermal performance.
The commercial schemes we look at rarely stack up on renewables from a financial perspective.
EPCs are a joke as they push you towards VRF solutions that are electrically bias and away from gas. Reality is that mains electricity is 40% efficient and 35% once you take in to account distribution losses. Gas is far better from an energy point of view being 90% eff on a modern boiler. The whole renewables issue needs far more debate. The bottom line is that the system should be cost driven not fashion driven. Until that happens there will be no clear way forward. You would think with the way SBEM/EPCs work that the Government were pushing us towards nuclear power as every solution points towards electric heatpump solutions, but I dont think the government is that clever!

The EPC software is fundementally flawed and incredibily badly run by BSRIA. We get regular software updates that cause major problems on the project we are working on. The software updates land with no warning and can change the results we get by as mush as 16% either way. This means that some buildings go from as good result to a poor result or the other way for no reason!! From our perspective the whole process needs scraping and something far simpler introducing.
Ranting over for now!

does NILAN have a UK site?

Code 3 is easily acheived in different ways.
The questions are how much do you want to spend and do you care about the future and residents running costs.
We installed 260 Nibe EAHP back in 2007 in Leicester in 55-70m2 new build apartments.
Keeping the argument simple and ignoring SAP and CfSH consider the following.
Heat loss reduced to 1.0-1.8kw
Air tightness tested to 3-4.4m3/m2@50Pascals
Immersion heaters disabled
Average annual all Energy (electric) consumption 7,170kwh compared to an Build Reg all electric apartment at 11,775kwh
Conclusion- useful improvement but not good enough for the future. If you want to know more then e-mail me at david@carbonlegacy.co.uk