BER Technical thread

galwaytt

...can I ask a general u-value question, because the BRE calculator I have doesn't have the option for the particular construction I want to get a u-value calculation for.

To wit: 102mm brick on 50mm cavity on 215mm hollow blocks (uninsulated) with 120mm warmboard to inside face.

Just looking for an indicative u-value of what that may be.

sydthebeat

u value = 0.16

galwaytt

sydthebeat wrote: »

u value = 0.16

..thanks Syd

MOTM

sydthebeat wrote: »

u value = 0.16

Agreed. Or invert the hollow block default (2.4 uninsulated) from DEAP table s3 and add the resistance of the other layers for a similar result.

GHER

Hi, I have a query about range cooker / boilers and range cookers that heat hot water only.

In Appendix B, 4.2 "Single burner range cooker/water heater. Some ranges provide a cooking function and some or all domestic hot water without providing space heating. Such a range can only be specified as a water heater if the water heating function can be provided independently from the cooking function. The efficiency is taken from Table 4a. If it is unclear whether cooking and water heating are independent, the range should not be included"

Surely this means that it should be ignored in Deap as having a water heating function, not completely ignored even as a room heater?????

Same query with B, 4.3 - "Single burner dry heat range cooker. This type is an appliance with a single burner that provides a cooking function. It is not included in DEAP calculations."

It is not included as a boiler but surely it's not completely ignored, even as a room heater? Whether it's solid fuel or oil, it doesn't need to be used as a cooker to heat the room so why would it be ignored as a room heater??

The reason I ask is because I was classifying the range cooker as a room heater when identifying rooms that were heated in a dwelling with inadequate heating. What's the logic behind ignoring it completely when it is quite clearly is capable of heating a room and doesn't need to be used as a cooker to do so???

I know it can't be classified as a room heater on it's own for primary or secondary heating energy efficiencies.

Thanks in advance to any answers.

descol

Sydthebeat
Would you mind letting me have the name and spec for your U value calculator - PM me if you wish
thanks
Descol

sydthebeat

pm sent

sydthebeat

GHER wrote: »

Hi, I have a query about range cooker / boilers and range cookers that heat hot water only.

In Appendix B, 4.2 "Single burner range cooker/water heater. Some ranges provide a cooking function and some or all domestic hot water without providing space heating. Such a range can only be specified as a water heater if the water heating function can be provided independently from the cooking function. The efficiency is taken from Table 4a. If it is unclear whether cooking and water heating are independent, the range should not be included"

Surely this means that it should be ignored in Deap as having a water heating function, not completely ignored even as a room heater?????

Such a range can only be specified as a water heater if the water heating function can be provided independently from the cooking function. The efficiency is taken from Table 4a. If it is unclear whether cooking and water heating are independent, the range should not be included

i read that as saying it shouldnt be "specified as a water heater" but it makes no mention of ignoring from a space heating point of view.

MOTM

sydthebeat wrote: »

i read that as saying it shouldnt be "specified as a water heater" but it makes no mention of ignoring from a space heating point of view.

"without providing space heating" is stated in b4.2 when it doesn't heat rads. Otherwise, why not say that your electric cooker is a roomheater?

sydthebeat

MOTM wrote: »

"without providing space heating" is stated in b4.2 when it doesn't heat rads. Otherwise, why not say that your electric cooker is a roomheater?

yeah correct, i was focusing on the wrong thing.

so im not quite sure then what GHER is asking.
If the cooker cannot provide space heating, then it shouldnt be considered a room heater. Seems logical enough.

blacktea

descol wrote: »

Sydthebeat
Would you mind letting me have the name and spec for your U value calculator - PM me if you wish
thanks
Descol

hi Syd, if i could also get a link by pm to that u value calculator it would be appreciated. Thanks, blacktea

galwaytt

...another curious question.

I got a call from BER assessor on the issue of Psi values. According to him, our (calculated and accredited by a Notified Body) figures are 'too low' causing him a problem in getting a particular build to meet Part L.

Could I get a laymans version of why a Psi value can ever be too low ?? Confused I am !

sydthebeat

just checked, the lowest value that can be inputted is 0.0001

BryanF

By any chance does he mean the fabric results are to low (ie better than the backstop values) so the % of renewables will have to increase?

If you get my meaning...

Handsandtools

The real value will change, depends on moisture level in structure and time of the year. As far as I know there's no tests done on thermal bridges and Psi values depending on weather conditions in Ireland.

galwaytt

Handsandtools wrote: »

The real value will change, depends on moisture level in structure and time of the year. As far as I know there's no tests done on thermal bridges and Psi values depending on weather conditions in Ireland.

Incorrect.

Handsandtools

Is there any tests done?
Pressure difference in winter and summer causes structure to accumulate moist in it!

sydthebeat

have a ridiculous situation here with a Prelim DEAP Part L assessment.

everything complies currently, standard oil, solar, HRV, and wood stove configuration.
air changes per hour rate = 0.12

if i make this 0.15 EPC fails
if i make it 0.1 EPC is fine but renewables fail.

so i have to tell the clients to make the build air tight, not to much, not to little, but just right... "Goldilocks" tight....

there are serious problems with these algorithims........

Rabbo

It all stems from the ridiculous renewables requirements. There's rumours going of them possibly reducing them.

Have you looked at the possibility of photovoltaics? I'm finding that it's much easier to achieve compliance with a small array and costing much less than equivalent tube setup

sydthebeat

the selection of products is fine with the clients, they are very happy with solar thermal.

the problem i have with it is the link between energy demand and renewable input.

a solar collector on a new house is deemed to provide a significant lesser amount of energy when compared to an retrofit installation on an old house (with the very same ancillary arrangement {cylinder, pumps, orientation, population equv} etc)

this is simply wrong and fantastical

its ridiculous to have a situation where the more you make the dwelling efficient, the less the renewable source provides... becuase thats just patently not correct.

sydthebeat

i know the 'Heat Pump' situation is up for change, hadnt heard anything about the renewable requirement.

galwaytt

sydthebeat wrote: »

its ridiculous to have a situation where the more you make the dwelling efficient, the less the renewable source provides... becuase thats just patently not correct.

^^^this.

We've had to recently manufacture a 'lower spec' wall specifically because of this, for a particular project.

This is just nuts. It flies in the face of everything we know about good building.

The more this goes on, the more likely people are to disregard the relevancy of BER altogether.

sydthebeat

galwaytt wrote: »

The more this goes on, the more likely people are to disregard the relevancy of BER altogether.

i personally try to keep references to BER and DEAP (Building reg, Part L) separate as it leads to so much confusion... even with construction professionals

had quite a time the other day trying to explain to an engineer that he should be looking for a "preliminary DEAP assessment report" as part of his commencement documents and not a "provisional BER certificate" because the provisional BER certificate has nothing to do with building regs and doesnt show any compliance or not with Bregs.

on the DEAP calculations, having it go so far as to lower a wall construction u value in order to comply is simply farcical and, in my opinion, an indictment on the lack of real world understanding by the compliers of the algorithms.

MOTM

sydthebeat wrote: »

the selection of products is fine with the clients, they are very happy with solar thermal.

the problem i have with it is the link between energy demand and renewable input.

a solar collector on a new house is deemed to provide a significant lesser amount of energy when compared to an retrofit installation on an old house (with the very same ancillary arrangement {cylinder, pumps, orientation, population equv} etc)

Is it a solar water heating.system or does it include solar space heating? The renewables contribution from the solar water heating is not going to change with different space heat loss parameters in DEAP.
What is the renewables contribution in this dwelling from solar and stove with each airtightness scenario?

sydthebeat

MOTM wrote: »

Is it a solar water heating.system or does it include solar space heating? The renewables contribution from the solar water heating is not going to change with different space heat loss parameters in DEAP.
What is the renewables contribution in this dwelling from solar and stove with each airtightness scenario?

good point, i was of the incorrect opinion that it does.

the situation above still stands however, where a 'goldilocks' air tightness result is required to comply. The air tightness is really the only 'unknown' when doing these assessments so its interesting to play with them to see how different results affect the outcome.

In this particular assessment, i have bitten the bullet and specified the provision of a third solar collector to ensure theres no confusion on final assessment.

MOTM

sydthebeat wrote: »

good point, i was of the incorrect opinion that it does.

the situation above still stands however, where a 'goldilocks' air tightness result is required to comply. The air tightness is really the only 'unknown' when doing these assessments so its interesting to play with them to see how different results affect the outcome.

In this particular assessment, i have bitten the bullet and specified the provision of a third solar collector to ensure theres no confusion on final assessment.

I've said it before and I'll say it again. If TGD L defined "reasonable" as a percentage and not an absolute this wouldn't be an issue.

THE DON FANUCCI

Right,
before i ask my assigned certifier i'll ask it here first;

I'm going starting a new build soon, and I want to know if you think this will comply with part-L regulation?

2,400 sq. ft. 2storey house,

100mm block, 100mm pumped insulated cavity, 100mm block walls,
sand and cement plaster internally (on the external walls).
100mm insulation under concrete floor
220mm moy metac in first floor joists and 220mm in attic joists.
sealed airtight tape around double glazed windows and doors.

wooden log only stove in sitting room with back boiler.
oil central heating also.


any other energy saving ideas I can add to this house that won't break the bank?



(I also have an open fireplace in other sitting room)

THE DON FANUCCI

Right,
before i ask my assigned certifier i'll ask it here first;

I'm going starting a new build soon, and I want to know if you think this will comply with part-L regulation?

2,400 sq. ft. 2storey house,

100mm block, 100mm pumped insulated cavity, 100mm block walls,
sand and cement plaster internally (on the external walls).
100mm insulation under concrete floor
220mm moy metac in first floor joists and 220mm in attic joists.
sealed airtight tape around double glazed windows and doors.

wooden log only stove in sitting room with back boiler.
oil central heating also.


any other energy saving ideas I can add to this house that won't break the bank?

I haven't done any deap/ber yet

(I also have an open fireplace in other sitting room)

sydthebeat

THE DON FANUCCI wrote: »

100mm block, 100mm pumped insulated cavity, 100mm block walls,
sand and cement plaster internally (on the external walls).
100mm insulation under concrete floor
220mm moy metac in first floor joists and 220mm in attic joists.
sealed airtight tape around double glazed windows and doors.

wooden log only stove in sitting room with back boiler.

each of the bold are under specified

if you are going with oil and wood stove, you will certainly need solar energy, be it PV cells or heat collectors.

to be honest that specification wouldnt pass 2008 regs, never mind 2011


the ONLY way to know for sure is to do a preliminary DEAP assessment.

most council not will insist in it when your commencement notice is submitted

THE DON FANUCCI

sydthebeat wrote: »

each of the bold are under specified

if you are going with oil and wood stove, you will certainly need solar energy, be it PV cells or heat collectors.

to be honest that specification wouldnt pass 2008 regs, never mind 2011


the ONLY way to know for sure is to do a preliminary DEAP assessment.

most council not will insist in it when your commencement notice is submitted

ok if I stick in 150mm pumped cavity and solar panels.
how expensive is mhrv and is it any good?

sydthebeat

THE DON FANUCCI wrote: »

ok if I stick in 150mm pumped cavity and solar panels.
how expensive is mhrv and is it any good?

Not ok. Like I said there's only one way of knowing.

You need to hire someone to do this

RORY O CONNOR

You need to get a preliminary BER done on the design and ensure that the U values for the floor, the roof and the walls are achieved, plus your solar panel and main heating system needs to be designed and specified in order to comply with the requirements of Part L. There are other bits to consider too and you will need a competent BER guy to provide you with the exact specifications in order to comply with Part L

sydthebeat

Anyone else noticed the completely ridiculous "error notices" they have included as extra now when you upload to NAS ??

there had been 87 of them, most of which made sense
http://www.seai.ie/Your_Building/BER/BER_FAQ/FAQ_DEAP/NAS_Errors_Notices/?viewall=1

now though there seems to be a lot more for some strange reason, and some of the are off the wall crazy.
The vast, vast majority of secondary space heating fraction inputs will be 0.1... but yet i get a warning to say that "unexpected secondary space heating fraction" ??

another one... apartment floor to ceiling height of 2.57 and i get "One or more floor height is not within the expected range"... like WTF.. what range do they expect??

ive gone from on average having 1 or 2 error notices (usual ones to be expected) to on average 5 or 6.

do they not realise that over loading error messages will just lead to them being disregarded completely?

Rabbo

Totally agree. When I used to get the one or two error notices, I used to put in a little note before publishing saying why I didn't think they were an issue. Now, when there's so many non sensical notices, I don't bother anymore. It's amazing that the 0.1 secondary space heating fraction error is still up there since they updated it a few weeks ago.

Saying that, all that inconvenience pales in comparison with the new 20 page Heat Pump methodology for new builds. The dealing with HP manufacturers to give you required data, the interpretation and filling in of the endless figures, trying to get a plumber to sign off on the design and then you learn that he decided to install a slightly different heat pump putting a question over the whole houses compliance with building regs.

Or better again, the air tightness exceeding expectations, reducing the heat demand and effectively making the house non-compliant with the renewables requirements just because it is too efficient.

sydthebeat

Rabbo wrote: »

Or better again, the air tightness exceeding expectations, reducing the heat demand and effectively making the house non-compliant with the renewables requirements just because it is too efficient.

yeah... that ones a doozie alright.... :rolleyes::rolleyes:

i wouldnt mind but the solution is so simple... just make it a percentage of the final energy demand.

10% of 60 kwhr is 6kwhr renewables required for a typical A3 rating

10% of 40 kwhr is 4kwhr renewables for an A2 etc... thus making it more attractive to become more efficient...

and also leads to greater "first principles" approach to energy efficient building than the "bolt on technology" we currently need to get over the line....

sydthebeat

Rabbo wrote: »

Saying that, all that inconvenience pales in comparison with the new 20 page Heat Pump methodology for new builds. The dealing with HP manufacturers to give you required data, the interpretation and filling in of the endless figures, trying to get a plumber to sign off on the design and then you learn that he decided to install a slightly different heat pump putting a question over the whole houses compliance with building regs.
.

just on this... what i do is send on the xml file to the heat pump suppliers and let them input their details into it, thus letting them take the responsibility for correct inputs.
they then send me back the xml file and i complete it.

Rabbo

sydthebeat wrote: »

just on this... what i do is send on the xml file to the heat pump suppliers and let them input their details into it, thus letting them take the responsibility for correct inputs.
they then send me back the xml file and i complete it.

I do the same but I was at a SEAI workshop recently and they are advising that the BER assessor has ultimate responsibility on what is inputted on those forms so, while it is useful to get manufacturers to infill the data, it is up to you to check that it is correct against the product fiches/certified data.

It should be a case of assessors just picking a product from HARP (or similar) and the data being transposed into DEAP. SEAI have said that this is the eventual goal but the current methodology was just a backstop as they had to react to the new ECODESIGN legislation and revise the way we assess Heat Pumps. I don't think BER assessors are qualified or should be expected to sift through reams of certification data and try to pick out relevant figures for assessment.

sydthebeat

Rabbo wrote: »

they are advising that the BER assessor has ultimate responsibility on what is inputted on those forms so,

Typical SEAI stock answer really....

however this is the pertinent issue

Rabbo wrote: »

I don't think BER assessors are qualified or should be expected to sift through reams of certification data and try to pick out relevant figures for assessment.

we are absolutely NOT qualified to assess whether the data provided by the HP manufacturers are accurate or not.... surely accepting them is akin to (or exceeds) accepting an architect or builders word that the ACDs have been adhered to.

simply throwing up a 20 page "guideline", at any stretch, does not making assessors qualified to assess this information.

andy6

This is probably in the wrong section? Can anyone recommend a BER assessor in Arklow thanks!

descol

I can't see the appropriate place for this query - if anyone on the BER tread can assist - it would be appreciated

My query relates to PV input into DEAP

There seems to be two inputs required - one being the Delivered Energy - which in my case is 4000 kWh p/a the other is a figure for Part L contribution

Can anyone advise how the Part L contribution is calculated ?

thank in advance

Descol

sydthebeat

https://www.boards.ie/discussion/comment/119546443#Comment_119546443

its the same figure.

unless youre constructing a new dwelling, its inconsequential

how did you get to such a clean figure as 4000 kWh/yr?

descol

thanks Syd - somebody did tell me it was the same figure - good of you to confirm - I got the 4000 figure from the PV company - 10400w panels -does that make sense ?

descol

sydthebeat

https://www.boards.ie/discussion/comment/119548052#Comment_119548052

do you mean 10 x 400 watt panels??

if so you need to use the formula 0.80 × kWp × S × ZPV to work out the kWh/yr figure.

so assuming youve a south facing roof at 30 degrees, thats 0.8 x 4 x 1074 x 1 = 3436.8 kWh/yr (which is the figure you use in DEAP for delivered energy)

note, any other orientation or roof angle, or any over shading, will mean a reduction of this figure

BAABAA96

Hi All,

I'm in a similar situation. I've just bought an old ex-council house in Dublin (I believe from the 1930's). The BER advice we got was a little frightening and the costs involved would prohibitive to get everything done at this stage.

Would anyone have recommendations on where to start with bringing up the energy rating of the house?

In my head I would probably do the following, then try to save towards some of the other jobs:

1 - Attic insulation - Everyone I've spoken with said I should DIY this, even with the grant available. Anyone with similar experience, or anyone that has got a professional to do it? I'm not the handiest of people

2 - Windows and doors - We have someone organised to look at these but basically the windows are doors are old and leaking heat (tangible drafts on some)

3 - New flooring - we have picked out a nice 12mm wood floors with a heavy underlay

4 - heating controls upgrade - The boiler seems to actually work well so I dont think it needs replacement, but getting better control over the time and zone of the house that gets heated is surely worth investing in?

If anyone has any recommendations please let me know!!

descol

Hi out there - grateful for comments on retrofitting glass in pvc framed windows

If old glass, in either single or double glazed windows is replaced with something like the "energlaze" product - and the frames remain - what - if any - improvement can be expected in the U value of the overall window ?

thanks

descol

sydthebeat

https://www.boards.ie/discussion/comment/120137857#Comment_120137857

is this a technical BER question, or just a general query?

Rougies

Hi, sorry if this question has been asked before. After looking at multiple BER advisory reports, it always lists suspended timber floors as "No Upgrade" available. Any idea why this is? I know suspended timber floors can be insulated, although it's a big job for sure.

Muahahaha

Just wondering does there exist a tick list of measures needed to be taken to achieve an A2 rating? Failing that is the DEAP(sp?) software that BER results are based on available publicly or only by license? Ive done some measures to my home and am getting more done next month (solar) after which a BER will be done for a grant. But would like to know approx what rating the house is right now, what impact the solar will have and what more needs to be done to get up to A2 or close to it

sydthebeat

https://www.boards.ie/discussion/comment/121625019#Comment_121625019

there are older versions of the software available to download as an xls file (google deap software excel file)

the current system is web based and you need to be an assessor to log in to use it.

so while the older system is outdated, it ill give you a general idea of the uplift you get from your upgrades.

be doubly warned though:

the xls spreadsheet is quite detailed and much harder interface to follow in comparison to the web based system and even the old 3.2 interface

plus, you will need to study the DEAP manual intensely, as the conventions can be quite weird, and the definitions of some things can be not what you expect

Muahahaha

Thanks for that Syd though it sounds like its beyond my station if I dont fully understand the fabrics of buildings to begin with.

Would you know of any resource where a tick list of what is typically needed on building a new home to A2 is published? I know this isnt an exact science but Im just trying to get an idea of where Im at. So something that would list measures XYZ needed and variations thereof. Ive an idea in my head of what it requires in terms of insulation, heating and renewables having seen friends recently built A2 rated homes but Im just looking for a resource that would confirm what I think I know and maybe add to it.