A3 Rated Ber

Katz83

I am just wondering would this be enough to get a BER Rating of A3

Oil with radiators condensing oil boiler that is
Insert Stove in sitting room
Stove with back boiler in kitchen dinning area
7 day programme for heating system with vales on the radiators and the heating system zoned
Solar Panels for hot water
Double Glazed Windows
Pumped Cavity with 150m insolation
we do not have a draft lobby.

would this be enough to get A3 Rating . Has anyone got an A3 Rating and if so what spec did they use

I was all about underfloor heating Air to Water heat pump but have heard alot of horror stories so drifting away from that idea and going with the more conventional method

Jimbo

It's impossible to say without carring out an assessment as there are other factors involved e.g. floor area, orientation, roof and floor insulation, glazed areas, etc etc.

You need to get a good BER assessor who will be able to advise the best configuration for your budget. You will also need the assessment done at this stage to check for compliance with building regs.

who what when

You havent given nearly enough information but if the rest of your spec is as average as that then i would say youre barely into B1 territory.
But as the previous poster stated its impossible to know without doing the actual BER

d'Oracle

A's are hard to get.

As you have poste no information about your house, then no-one can say.
But I SERIOUSLY doubt you would get near an A3 with oil, a stove, only pump-filled walls and no draught lobby.

Also, the actual performance you get will probably be a lot poorer than the BER would indicate.

Toplink

d'Oracle wrote: »

A's are hard to get.

As you have poste no information about your house, then no-one can say.
But I SERIOUSLY doubt you would get near an A3 with oil, a stove, only pump-filled walls and no draught lobby.

Also, the actual performance you get will probably be a lot poorer than the BER would indicate.

If you added an air permeability of less than 3 m3/hr/m2 in conjunction with a an MHRV system (high eff) then you would be pushing close but again as previous posters have stated you need a proper assessment carried out.

fat__tony

Jimbo wrote: »

It's impossible to say without carring out an assessment as there are other factors involved e.g. floor area, orientation, roof and floor insulation, glazed areas, etc etc.

You need to get a good BER assessor who will be able to advise the best configuration for your budget. You will also need the assessment done at this stage to check for compliance with building regs.

Very much this.

On inspection of the OP I'd hazard a guess at a B1 energy rating.

d'Oracle

Are we talking about a new build here?

bamboozle

forgive the ignorance but what is a draft lobby?

d'Oracle

bamboozle wrote: »

forgive the ignorance but what is a draft lobby?

A porch...:D

Basically when you have an outside door and an inside door on the front entrance. So you can close the outside one before opening the inside one.

who what when

d'Oracle wrote: »

A porch...:D

Basically when you have an outside door and an inside door on the front entrance. So you can close the outside one before opening the inside one.

And they make sweet phuke all difference

badur77

I'm working on international typology project "Tabula" and I have done lot of simulations at work "what to do to get A3" and I would really say:
To get A3 is practically impossible without heat pumps and perfectly insulated walls, full zone control, low-E argon filled windows and solar thermal panels

Draught lobby is considered in BER calculations if it has at least 2 sqm of area, but it has very small impact so i wouldn't be worry bout it

sydthebeat

badur77 wrote: »

I'm working on international typology project "Tabula" and I have done lot of simulations at work "what to do to get A3" and I would really say:
To get A3 is practically impossible without heat pumps and perfectly insulated walls, full zone control, low-E argon filled windows and solar thermal panels

Draught lobby is considered in BER calculations if it has at least 2 sqm of area, but it has very small impact so i wouldn't be worry bout it

if your struggling to get to A3 a draught lobby is a very low cost low tech means of improving your rating, it should be a definate inclusion.

d'Oracle

badur77 wrote: »

I'm working on international typology project "Tabula" and I have done lot of simulations at work "what to do to get A3" and I would really say:
To get A3 is practically impossible without heat pumps and perfectly insulated walls, full zone control, low-E argon filled windows and solar thermal panels

Draught lobby is considered in BER calculations if it has at least 2 sqm of area, but it has very small impact so i wouldn't be worry bout it

Interesting.

Have you not found that the electrical element of the heat pumps make it hard to get a rating up?

sydthebeat

d'Oracle wrote: »

Interesting.

Have you not found that the electrical element of the heat pumps make it hard to get a rating up?

AFAIK heat pumps will "break even" at efficiencies of approx 270% (which matches the 2.7 multiplier energy factor on fuel).

some HPs these dasy can have efficiencies in the region of 400%

badur77

d'Oracle wrote: »

Interesting.

Have you not found that the electrical element of the heat pumps make it hard to get a rating up?

Some of them have the efficiency of 400%, so even considering 2.7 factor for electricity, even the best 97% efficient condensing boilers will be always miles behind the heat pumps

sinnerboy

Careful here .

Typical example

This ( very good ) heat pump has a COP of 380%

A breakdown of it's varying performance over a range of source/output temperatures can be found on page 1 here

The COP you see on the HARP data base is an average performance taken over 3 source/output temperature references ( A means air W means water ) as follows (A7_W35 + A7_W45+A2_W35) / 3 . In the case of the model in question we get (3.5+4.5+3.4) / 3 = 3.8 or 380%

Now an output water temperature range of 35-45 degrees is fine for low temperature distribution such as UFH . It is no good for DHW .

Look back again at Page 1 here

A7_W55 is 2.6 . A-7_W55 is 1.5 . We don't have a figure for A0_W55 but we can guesstimate 2 i.e. a COP for mid winter for DHW of 200% .

The condensing boiler wins that one .

.

sinnerboy

Bear in mind that the COP measures the performance just at the HP unit and does not take into account the electrical energy consumed by the distribution of the heat .

Comparing a 1. boiler / rads installation with 2. HP / UFH installation we get

1. high temperature / low volume of water to pump around circulating for a shorter daily heating period
2. low temperature / high volume of water to pump around circulating for a longer daily heating period

Whens the last time you carried a bucket of water ? Heavy isn't it ? The cost of pumping it around is significant .

.

badur77

So why does the DEAP software always give the better BER for the HP than for the condensing boiler?

It takes to account elecricity consumed by the pump and also lesser efficiency for DHW during the winter time. Do some simulations in DEAP and you will see.

sinnerboy

I don't know Badur77 but I am skeptical about it .

Why does the SEI method ( an "interim" one by the way ) only select 3 source/output performance factors which clearly relate to space heating ? Why is at least A7_W55 not factored in here ?

Why did they Grant Aid renewables during the recent boom to the tune of tens of millions pa whist spending consistently less than €2m pa on loft insulation and draft proofing for those on low incomes .

Sorry for the rant .

I don't trust SEI or DEAP on this one .

Look around this ( and other ) forums and it will not take you long to find HP punters with very , very high elec bills .

You will not read " I just put in a condensing boiler and my fuel bills are huge"

sinnerboy

Personally I would await the findings of this EU research before recommending a heat pump to anyone

The project aims at overcoming market barriers to a wider application of heat pumps, namely the lack of robust data on the conditions "in real installations" influencing reliability and seasonal efficiency. The main parameters influencing systems efficiency are:

- efficiency of heat pump unit
- quality of installation
- design and temperature level of the heating system
- insulation level of the building envelope
- climatic conditions

So the DEAP COP can NOT be matched against the % efficiency of a CB . It's much more complex than that .

badur77

Well, I understand your point but at the moment at my work I have to stick to DEAP procedures.

The DEAP calculation is simple, so let's follow it:

92% condensing boiler - means that 92% of the generated heat stays inside and 8% is wasted, goes out through the flue.

380% heat pump in DEAP is the device, which for every unit of energy you put in, returns 3.8

When there is no underfloor heating, efficiency adj. factor is 75%. So, we have to get efficiency down to 285%

Now, to have more comparable result, let's divide it by 2.7 conversion factor for electricity, so now we have pure value of 105,55% for space heating

For DHW there is special formula assuming using immersion during the winter, so our 380% pump is brought down to about 168%. Divided by conversion factor 2.7 it gives us 62,2% efficient domestic HW system

Now, we have to get primary energy for our 92% CB

92 / 1.1 = 83% for Space heating and DHW

Summary

Heat pump: real efficiency (including conversion factors) 106% for SH and 62% for DHW

CB: 83% for both

In average conditions there is always more energy demand for SH than for DHW, therefore weighted average would be alway bias towards the SH

Hence, it would be always beter than 83%,
So - CB failed in that simple calculations

sinnerboy

No argument with your methodology or logic badur77 but I draw a different conclusion .

I have re run an assessment for a house ( 102m2 B1 ) which was first input with a CB and now an ATW HP

I am focusing on delivered energy i.e. running costs now ...

CB
SH 4720 kwhr/a
HW 1600 kwhr/a
Total 6320 @ €0.05 cost for Nat Gas = €316

ATWHP
SH 1620
HW 549
Total 2170 @ €0.15 standard rate elec = €325

However - and we may have to agree to disagree here

1. I note DEAP assigns the same 175 kwh/year for pumps for both CB + ATW HP . I don't believe that
2. I don't trust the SEI COP determination method
3. I believe that HP's require in effect a 5 legged stool to stand up 1 COP 2 Expert installation 3 Expert Design 4 Excellent building fabric 5 End user education

CB installations are not unaffected by this list but the end use performance is much more robust . In other words they still perform well even if one or even two of the five elements are not in place .

sinnerboy

sinnerboy wrote: »

No argument with your methodology or logic badur77 but I draw a different conclusion .

I should add that whist I am challenging you respectfully I am not confronting you or trying to "trip you up"

LoTwan

OK... treat me like a complete unknowing idiot (because I am )

At the moment you are comparing a condensing boiler and a heat pump (gas & AS in the example above). As solar (or another renewable source) is required to comply with part L (ok, I said I was completely unknowing, but I know a little about Part L, although I nearly called it K there) so when looking at comparrisons, given the requirements of part L, do you not have to consider the cost/benefit implications of the solar panels too? (unless of course you have managed to comply with L without solar, if that is possible). There were altogether too many parentheses in that paragraph, sorry about that.

Also, is it realistic to make calculations using standard rate electricity when someone who installs a HP will, more than likely, install a night meter.

Oh, and is there any chance you could do the above calculation with oil rather than gas because gas isn't an option down here :rolleyes:

sinnerboy

LoTwan -too much in that series of queries .

Sorry but you need to hire someone to provide answers

LoTwan

I have had my questions answered elsewhere. I was just wondering how valid it was to compare two heating systems as independent costs when both have other requirements/cost implications.

sinnerboy

Your right there . A holistic overview is required .

LoTwan

sinnerboy wrote: »

Your right there . A holistic overview is required .

Clearly my second attempt did a better job of getting my point across :-)

sinnerboy

CB
SH 4720 kwhr/a
HW 1600 kwhr/a
Total 6320 @ €0.085 cost for Kerosene Oil = €537.2

LoTwan

Thanks for that Sinnerboy.

tails_naf

sinnerboy wrote: »

No argument with your methodology or logic badur77 but I draw a different conclusion .

I have re run an assessment for a house ( 102m2 B1 ) which was first input with a CB and now an ATW HP

I am focusing on delivered energy i.e. running costs now ...

CB
SH 4720 kwhr/a
HW 1600 kwhr/a
Total 6320 @ €0.05 cost for Nat Gas = €316

ATWHP
SH 1620
HW 549
Total 2170 @ €0.15 standard rate elec = €325
.

Hi sinnerboy - just a quick question on these figures.
I've just moved into a 320m2 house, which I did my best to exceed current building regs - rough stats are:
0.18u walls (~300m2), 0.12u cieling (140m2), low-e argon filled double glazed windows, UFH, with 0.14u floor (180m2), MHRV, etc.

My rough calcs for heat loss (with outside temp around 4c), is 4kw, or 96kwh/day.

The numbers you give above are very impressive for a 100m2 house - it comes out at 17kwh/day.

I know I should average over the year, and the months actual heating is required, plus factoring in solar gain with windows and solar panels, will bring the average down somewhat, but do you have a finger in the air guess for if my numbers seem reasonable?

note: at 96kwh a day, and using oil at 8c? a kwh, this gives 7.5 euro/day for heating, which is quite considerable, for a house that is supposed to be energy efficient!!

sinnerboy

Figures knit in a crude way .

DEAP tells me ( for my 102m2 house)
Jan - ext temp 5.3 degrees . Monthly demand 973 kwh. Or 31 kwh/day .

So comparing building sizes - 100m2 X 3 = 300m2

31kwh/day x 3 = 93kwh/day .

Both house are probably "B rated" . Bit misleading eh ?