Part L Building Regulations 2011

Chris Arch

muffler wrote: »

Keep up at the rear please :rolleyes:

I was talking about the wall insulation not the roof... I think that Beyondpassive means that the 100mm cavity insulation cannot be fitted on site for its certified performance.

This is of concern because I am using this system in a design just now and I intend to use it again.

If Beyondpassive is right, it means that the BBA certificates are flawed and British Standards for testing inadequate.

I am familiar enough with corruption within regulatory bodies not to ignore Beyondpassive's claim.

If this subject was already debated, just let me know where...

Chris Arch

sinnerboy wrote: »

Mod Warning to Chris Arch

"Watch your tone here. this forum is good place to discuss and learn if you use it properly. "

Chatting is what I am doing... Where was my tone inadequate? Please let me know...

sinnerboy wrote: »

Tips

- if someone goes to the trouble of providing you with a detailed link please read it before dismissing it as having "too many pages"

If you are talking about the 200 pages thesis... I am not an engineer and I cannot read it.

sinnerboy wrote: »

- read carefully what others have posted. Beyondpassive did not suggest anything with regard to BBA certification he simply expressed his expectation.

What did he suggest then? He is an expert in this subject this is why I am taking him seriously on this issue. If a material is certified to achieve a certain U-Value and if Beyongpassive pretends that this U-value cannot be achieved, then what do you understand there? Beyondpassive stated that the system of a 100mm fully filled cavity cannot achieve a much better U-value than 0.20. However the certified U-Value is much better than that...

sinnerboy wrote: »

- take sometime to reflect before posting again - or you will be given time in the form of a ban

Do you mean that you want me to stop questioning this 250mm cavity and stop questioning Beyondpassive's assertion?

Every post I send is the result of a process that can be called thinking. But as it seems that I am not welcome here... Then I will spare you the ban... There are plenty of other places to chat where I will be spared the moderators' bullying...

Regards

Chris

beyondpassive

Hi Chris,

100mm of this insulation gives a lamda of 0.16, depending on the block lamda, I have concerns that this is using Autoclaved Aerated concrete block and excludes cavity ties. That is why it is safer to ask for the lamda of the insulation alone. There are a number of types of conductivity and I use lamda 90/90 wher PIR (polyisocanurate) is 0.024,

Lamda 90/90 www.bbacerts.co.uk/pdf/BBAdatasheet_040i3%20(2).pdf
Typical insulations www.timsa.org.uk/TypicalLambda90Table.pdf

Chris Arch

Hi Beyondpasive... This is now much clearer... You are using the 90/90 U-Value, which is, to my understanding, not yet used in Part L 2011 nor by the manufacturers.

When will this 90/90 U-Value be officially used? One of the Documents that you provided is dated from 2010...

Also I found that one of the documents assumes the thermal resistance of PIR insulation to 0.020 and the other one to 0.022 while the manufacturer that I am specifying declares his PIR insulation to have a Lambda of 0.021. This appears very approximate to me...

Sorry to insist on this subject, but the documents provided state that the testing standards are changed as well as other assessments, confirming my presumption of inappropriate testing...

Thanks for answering my questions...

sydthebeat

fclauson,

please edit the previous post to make it legible

Chris Arch

fclauson wrote: »

see attched

HP just do not do it as for the DHW production you have to down rate the heat pump output (see DEAP manual)

Have you tryed an air to air Heat Pump as a secondary heating system coupled with an air to water Heat Pump as the primary heating system?

sydthebeat

Chris Arch wrote: »

Have you tryed an air to air Heat Pump as a secondary heating system coupled with an air to water Heat Pump as the primary heating system?

besides the extortionate cost of doing that.....

the secondary heating source only provides 10% of heat energy so using an air to air heat pump as secondary adds absolutley nothing to the renewable requirement.

Chris Arch

sydthebeat wrote: »

besides the extortionate cost of doing that.....

the secondary heating source only provides 10% of heat energy so using an air to air heat pump as secondary adds absolutley nothing to the renewable requirement.

I have used one with a gas boiler and 2 solar panels in a small detached house 2 years ago. The roof profile was not permitting to accommodate a third panel South that would have been required for compliance. The air to air heat pump did it.

Honestly they are expensive, but so are the solar panels and other sustainable heating systems. To my opinion and experience they were under-estimated in the previous version of the DEAP and probably in the new one as well. An air to air heat pump can warm-up a large part of small dwelling in about 10 minutes (providing that all internal doors are left opened). This is much more than the 10% attributed in the DEAP. I can't see solar panels being as efficient in Ireland.

sydthebeat

Chris Arch wrote: »

I have used one with a gas boiler and 2 solar panels in a small detached house 2 years ago. The roof profile was not permitting to accommodate a third panel South that would have been required for compliance. The air to air heat pump did it.

Honestly they are expensive, but so are the solar panels and other sustainable heating systems. To my opinion and experience they were under-estimated in the previous version of the DEAP and probably in the new one as well. An air to air heat pump can warm-up a large part of small dwelling in about 10 minutes (providing that all internal doors are left opened). This is much more than the 10% attributed in the DEAP. I can't see solar panels being as efficient in Ireland.

was it not possible to install a closer room heater which was wood dedicated?
That would have been a fracion of the cost.

If the heat pump is sufficient to heat the dwelling, then it is possible to include it as the primary heating source. With the panels as you have outlined it may have been possible that they would have sufficed to comply with renewable requirement.

Anyone using DEAP must understand that its basedon assumptions and algorithims designed as a basis to compared dwellings. It certainly does not offer specific results which take occupants actions into account.

Chris Arch

sydthebeat wrote: »

was it not possible to install a closer room heater which was wood dedicated?
That would have been a fracion of the cost.

If the heat pump is sufficient to heat the dwelling, then it is possible to include it as the primary heating source. With the panels as you have outlined it may have been possible that they would have sufficed to comply with renewable requirement.

Anyone using DEAP must understand that its basedon assumptions and algorithims designed as a basis to compared dwellings. It certainly does not offer specific results which take occupants actions into account.

A pellet stove would have required a long flue to be fitted due to the proximity of another dwelling 2 metres to the gable wall. Plus this is a small urban dwelling and the stove would have taken some space in the lounge or kitchen dinner. Last but not least, it was built for letting purposes and the air to air heat pump appeared much safer on a fire safety point of view. This was the client's choice but anyway I am not sure that a wood pellet stove would have provided compliance. You need to remember that these air to air heat pumps are up to 350% efficient.

Unless fitted with ventilation DUCT, they cannot be used as the main heating system. I never heard about such installation in a dwelling but I think it is used as such in offices and shops.

sydthebeat

Chris Arch wrote: »

A pellet stove would have required a long flue to be fitted due to the proximity of another dwelling 2 metres to the gable wall.

so?.... still cheaper than an air to air heat pump.

Chris Arch wrote: »

This was the client's choice but anyway I am not sure that a wood pellet stove would have provided compliance. You need to remember that these air to air heat pumps are up to 350% efficient.

theyre efficiency counts for very little renewables when inputted as secondry heating with electricity as fuel... as again, it can only account for 10%. I just checked an assessment right now and an air to air HP as secondry rose the renewable from 5.1 to 5.69.
whereas wood stove at 80% rose it from 5.1 to 6.79

thats a hugly expensive way of making up a very small amount of renewable.

Its certainly an option i wouldnt consider in view of all the other possibly better and lower cost options.

A wood stove of 80% simply offers a greater contribution. So if the A-A HP made up the difference then certainly the wood stove would have. Thats simple calculations.

Chris Arch wrote: »

Unless fitted with ventilation DUCT, they cannot be used as the main heating system. I never heard about such installation in a dwelling but I think it is used as such in offices and shops.

so to clarify, you specified an air to air HP with NO ducting ??? :eek: ... and this in a new build !!

Chris Arch

sydthebeat wrote: »

so?.... still cheaper than an air to air heat pump.

Some of us are interested with comfort... others with cheap solutions...

sydthebeat wrote: »

theyre efficiency counts for very little renewables when inputted as secondry heating with electricity as fuel... as again, it can only account for 10%. I just checked an assessment right now and an air to air HP as secondry rose the renewable from 5.1 to 5.69.
whereas wood stove at 80% rose it from 5.1 to 6.79

This dwelling was designed in Compliance with the 2008 regulations and we were also using 2 solar panels orientated South.

sydthebeat wrote: »

thats a hugly expensive way of making up a very small amount of renewable.

No... THis is a clever way to heat the dwelling in less than 10 minutes using a remote control... We call it technology...

sydthebeat wrote: »

A wood stove of 80% simply offers a greater contribution. So if the A-A HP made up the difference then certainly the wood stove would have. Thats simple calculations.

from what I remember the stove did not... but this was over 2 years ago and I have only kept the DEAP for the Air to air heat pump.

sydthebeat wrote: »

so to clarify, you specified an air to air HP with NO ducting ??? :eek: ... and this in a new build !!

If you are trying to be funny... I will laugh with you ...

If you are serious then do your homework and you will find that small air to air heat pump do not require ducting and that they work very well when fitted in the entry hall providing heat at first floor as well as ground floor.

Whatever, I am not selling them and I will not insist further defending their qualities... I just think that you probably never tested any and that you are only afraid of the cost...

I am personely more concerned about solar panels cost and the amount of energy saving that they bring. In South of France people are hesitating to use them because they are not sure to have their money back from the energy that they will produce... In South of France they have plenty of sun with tempratures reaching frequently 40deg. Celcius... I know that we should not think only about finance and that redusing our carbon footprint should be a priority... But for achieving this I think that heat pumps are much more appropriate than solar panels in Ireland.

sydthebeat

Chris Arch wrote: »

Some of us are interested with comfort... others with cheap solutions...
.

and some of us are interested in giving our client informed options...

Chris Arch wrote: »

This dwelling was designed in Compliance with the 2008 regulations and we were also using 2 solar panels orientated South.
.

i have never said anything to the contrary

Chris Arch wrote: »

No... THis is a clever way to heat the dwelling in less than 10 minutes using a remote control... We call it technology...

no, its a very expensive "bolt on" solution to a problem that doesnt really exist. Remote control heat pump in a house that has a gas boiler... now thats laughable. Ever heard of a digital programmer?
Id be more intrested in giving my client financial comfort by offering a more economical, and as explained above, better solution.

Chris Arch wrote: »

from what I remember the stove did not... but this was over 2 years ago and I have only kept the DEAP for the Air to air heat pump.
.

well ive just explained to you above that it would offer a higher renewable yield.

Chris Arch wrote: »

If you are serious then do your homework and you will find that small air to air heat pump do not require ducting and that they work very well when fitted in the entry hall providing heat at first floor as well as ground floor..

this simply gets better and better

sydthebeat

chris, obviously you are singing the praises of using an air to air heat pump as a secondary heating source and fair dues to any client who can afford such luxury. You are entitled to stand up for your specification.

however, in my view, the vast majority of clients wouldnt be in a position to install such an expensive item given the obvious economic cost of it. There are far better and more economical solutions to this secondary heating issue

Chris Arch

sydthebeat wrote: »

and some of us are interested in giving our client informed options...

Well if your were reading my posts you would now that the clients prefered the heat pump from the stove... You should be more attentive...

sydthebeat wrote: »

no, its a very expensive "bolt on" solution to a problem that doesnt really exist. Remote control heat pump in a house that has a gas boiler... now thats laughable. Ever heard of a digital programmer?
Id be more intrested in giving my client financial comfort by offering a more economical, and as explained above, better solution.

Have you ever tryed one? If so you would not compare it with a stove... It is just not comparable... I think that you are making a judgement on something that you never tryed before...

I have used stoves in other projects... Considering the cost of the pellets to be burnt compared to the electricity used by the heat pump and the 500euro purchase difference is fast reduced...

Have you informed your clients about this issue?

Poor Uncle Tom

If money isn't a barrier, why not advise the clients to build in an equatorial climate, job done.

Chris Arch

sydthebeat wrote: »

chris, obviously you are singing the praises of using an air to air heat pump as a secondary heating source and fair dues to any client who can afford such luxury. You are entitled to stand up for your specification.

however, in my view, the vast majority of clients wouldnt be in a position to install such an expensive item given the obvious economic cost of it. There are far better and more economical solutions to this secondary heating issue

an air to air heat pump cost approx. 1,000 euro + VAT, all included. If you count the stove price + flue + arrangement to protect the walls from overheating... the difference of cost on a small dwelling is about 0.3% to 0.2%...

sydthebeat

chris, believe it or not yes i have seen air to air heat pumps in practise. and yes im definitely not convinced by them. They suit a construction method with such a low energy demand, that its actually more economical to use the cost of that technology in an alternative manner so as to negate any need for them in the first place.

just a simple point to you... did i mention the word "pellet" anywhere in my posts?

im not trying to argue with you here because i know your not for turning, im simply making sure that if someone reads this that dont think that a-a Heat Pumps are a necessary / suitable source of secondary heating.

Chris Arch

sydthebeat wrote: »

chris, believe it or not yes i have seen air to air heat pumps in practise. and yes im definitely not convinced by them. They suit a construction method with such a low energy demand, that its actually more economical to use the cost of that technology in an alternative manner so as to negate any need for them in the first place.

just a simple point to you... did i mention the word "pellet" anywhere in my posts?

im not trying to argue with you here because i know your not for turning, im simply making sure that if someone reads this that dont think that a-a Heat Pumps are a necessary / suitable source of secondary heating.

I never said that... It is just an option that you appear to dislike...

Do you honestly think that solar panels are more efficient than heat pumps when used in Ireland?

I am not talking about the DEAP compliance but with real experience taking into consideration life time of the equipment, purchase and installation and energy saving?

sydthebeat

ok seeing as you want to continue this......

Chris Arch wrote: »

Do you honestly think that solar panels are more efficient heat pumps when used in Ireland?
?

why are you comparing the HP to solar panels? my argument is the comparison of wood stove and an air to airheat pump... please keep up.

Chris Arch wrote: »

I
I am not talking about the DEAP compliance but with real experience taking into consideration life time of the equipment, purchase and installation and energy saving?

i do not honestly believe that an electric piece of technology like a heap pump will in any way outlast a traditional arrangement of a wood stove...

we all know how much energy bills are going up.. electricity defintely is not immune.... wood as a fuel is not subject to carbon tax ....

see here for fuel cost comaprisons

please note very closely that day rate electricity delivered cost of a KW of energy in the standard band B is €0.257

compare that to a standard wood briquette of €0.077.

i rest my case.

Chris Arch

sydthebeat wrote: »

ok seeing as you want to continue this......

sydthebeat wrote: »

why are you comparing the HP to solar panels? my argument is the comparison of wood stove and an air to airheat pump... please keep up.

because you seem to be accepting solar panels as a green technology for producing energy while criticising the cost of a heat pump. As already explained, I think that value for money, heat pumps are more interesting.

sydthebeat wrote: »

i do not honestly believe that an electric piece of technology like a heap pump will in any way outlast a traditional arrangement of a wood stove...

Agreed, but there you deliberately ignore all the positive that can be produced by a heat pump.

sydthebeat wrote: »

we all know how much energy bills are going up.. electricity defintely is not immune.... wood as a fuel is not subject to carbon tax ....

see here for fuel cost comaprisons

please note very closely that day rate electrucuty delivered cost of a KW of energy in the standard band B is €0.257

compare that to a standard wood briquette of €0.077.

i rest my case.

Following your argument we should all use stoves as a primary heating system, because they have a longer life time than oil or gas or electric boilers or heat pumps...

I looked at the link that you provided:

Delivered energy cost, cent per kwh, 6.41 cents for pellet bag and 25.7 cents band B electricity.

The stove is 80% efficient meaning that out the 1 kwh produced only 0.8kwh heat the house while the heat pump is 350% efficient and out of the 1kwh of electricity, it produces 3.5kwh to heat the house.

We have a stove which produces 0.8kwh for 6.41 cents to heat the dwelling and a heat pump which provides 3.5kwh at 25.7 cents. This is equivalent to 8.02 cents per kwh for the stove and 7.35 cents per kwh for the heat pump (air to air system). The heat pump foot print is nearly 4 times lesser than the stove and the cost is about 0.67 cent cheaper for the output kwh.

Unless you can buy a bulk of wood briquettes the heat pump is cheaper per kwh. One think is sure, the stove may be cheaper, but in relation to the carbon footprint there is no comparison.

Chris Arch

While using a 98% efficiency gas boiler as a primary heating system, the air to air heat pump reduces the CPC when used as a secondary heating system while the stove is increasing it...

This is the interest of the air to air heat pump...

I will stop there for today...

Good evening.

brickee

Are these Part L regulations just infact guidelines and the idea to get as close to them as possible because they still keep the same minimums as pre 2011 -2008 just with better U Value's to aim for.

BryanF

brickee wrote: »

Are these Part L regulations just infact guidelines and the idea to get as close to them as possible because they still keep the same minimums as pre 2011 -2008 just with better U Value's to aim for.

brickee,
as the name suggests their 'regulations' :eek:

they are set-up to acknowledge (to some degree) that each house is different and so they have moved away from a set of u-values towards an overall assessment that requires compliance. that's why we've been hounding you to do a provisional BER, and then the fun starts:)

as you have started your build already, you will probably be working to the 2008 regs although you should have someone advising you of this!!!!

this is one of the many problems with our building legislation/ Building control system at the moment...

muffler

brickee wrote: »

Are these Part L regulations just infact guidelines

BryanF wrote: »

brickee,
as the name suggests their 'regulations' :eek:

Indeed they are.

I think brickee may be confusing the regs with the technical guidance documents which, as it says on the tin, are for guidance.

BryanF

muffler wrote: »

Indeed they are.

I think brickee may be confusing the regs with the technical guidance documents which, as it says on the tin, are for guidance.

indeed

but i fear there's more to this than a misunderstanding over the difference between legislative and guidance documents

brickee

BryanF wrote: »

brickee,
as the name suggests their 'regulations' :eek:
that's why we've been hounding you to do a provisional BER, and then the fun starts:)

as you have started your build already, you will probably be working to the 2008 regs although you should have someone advising you of this!!!!

this is one of the many problems with our building legislation/ Building control system at the moment...

OK after alot of reading and nothing sinking in it seems its a bit of a minefield and I will have to get this BER in and have a word with him set out my guides to make sure I'm on the right track cause one thing I've noticed from my reading is its not clear there is no one right way.....

sydthebeat

Chris Arch wrote: »

I looked at the link that you provided:

Delivered energy cost, cent per kwh, 6.41 cents for pellet bag and 25.7 cents band B electricity.

The stove is 80% efficient meaning that out the 1 kwh produced only 0.8kwh heat the house while the heat pump is 350% efficient and out of the 1kwh of electricity, it produces 3.5kwh to heat the house.

We have a stove which produces 0.8kwh for 6.41 cents to heat the dwelling and a heat pump which provides 3.5kwh at 25.7 cents. This is equivalent to 8.02 cents per kwh for the stove and 7.35 cents per kwh for the heat pump (air to air system). The heat pump foot print is nearly 4 times lesser than the stove and the cost is about 0.67 cent cheaper for the output kwh.

Unless you can buy a bulk of wood briquettes the heat pump is cheaper per kwh. One think is sure, the stove may be cheaper, but in relation to the carbon footprint there is no comparison.

chris im afriad your understanding of carbon footprint is flawed. carbon foot print does not begin when the electricity enters your property.

our national grid system works on approx 33% efficiency... basically, for ever 3 kwhr of energy that goes into our power stations, we get 1 kwhr of energy in return.
That is why we have a primary energy conversion factor of 2.7 for electricity in DEAP.
In simple terms that completely reverses your maths above which you purport that the heat pump is cheaper to run than a wood stove.
Make not bones about it, we all pay for this inefficiency in our electricity bills.
Also, dont be fooled that electricty is somehow a clean fuel? we still are heavilty reliant on fossil fuels for our national grid system.
This can also be seen when you change your secondary fuel source from wood to electricity... your carbon value actually goes up!!!
the carbon emmission factor for electricity is 0.643 kg / kwhr
the carbon emmission factor for wood logs is 0.025 kg / kwhr

thats means that wood is 25 times cleaner than electrcity. Do you understand this?

so to summerise... if you choose an electric heat pump over a wood stove as your secondary heat source in order to met building regulations:

1. you get less renewable input from the heat pump than the stove
2. it costs you more per energy unit to run the heat pump
3. it costs more to install the heat pump
4. you produce more carbon by the heat pump than the stove.

I think that tidies it up nicely.

Chris Arch

sydthebeat wrote: »

chris im afriad your understanding of carbon footprint is flawed. carbon foot print does not begin when the electricity enters your property.

our national grid system works on approx 33% efficiency... basically, for ever 3 kwhr of energy that goes into our power stations, we get 1 kwhr of energy in return.
That is why we have a primary energy conversion factor of 2.7 for electricity in DEAP.

Ok... I knew that there is now nuclear in Ireland, but I was not aware of the poor eficency of the grid... Where did you obtain the 33% figure from? Do you mean that only 33% of the energy produced by burning solid fuel is transmitted in the grid?

Also it must be noted that some of this electricity is generated by wind turbines and does not produce carbone emmissions in contrary to a stove that does...

It would be stupid politics to improve houses efficiency, cars efficiency and so on without improving the grid efficiency... Isn't there a big effort by the government to connect wind turbines to the grid? aren't we talking about a much efficient grid in the future?

Why did the previous DEAP software version reduced my CPC when using a heat pump as a secondary heating system while raising it when using a stove for the same purpose? I haven't tryed the new version but it should have a similar result.

sydthebeat

Chris Arch wrote: »

Also it must be noted that some of this electricity is generated by wind turbines and does not produce carbone emmissions in contrary to a stove that does...

It would be stupid politics to improve houses efficiency, cars efficiency and so on without improving the grid efficiency... Isn't there a big effort by the government to connect wind turbines to the grid? aren't we talking about a much efficient grid in the future?

Why did the previous DEAP software version reduced my CPC when using a heat pump as a secondary heating system while raising it when using a stove for the same purpose? I haven't tryed the new version but it should have a similar result.

wood fuel is currently consdier renewable energy source, much the same as wind.

currently wind generation is approx 11% of irelands power needs, there is a push to get this to a target of 40% by 2020. AFAIK the current input isnt referenced in DEAP but im open to connection on that.

of course, the national grid fuel system is a huge topic and not one fo rhere... so lets keep this on topic.

on the CPC issue, im not sure of your calculations, but any of mine that ive tried there has all been a very slight worsening of the CPC when choosing HP over wood fuel.