Heating cost

badgerhowlin

Hi,
I found this and was wanting to know if its accurate or not.

http://www.passivehouseandhome.com/Passiveenergycosts.html

Its saying that an A3 rated house costs €7.50 to heat 1 m2 per year

I have a HP installed and want to know how much the HP is saving me so i can actually save that amount. Not looking for 100% correct info, just ball park.

sas

Those figures look very very high to me.

I'm A2, 300m2.

According to them it should take €3.75 per m2, or 25kw per m2 per year.

For my home that would be 7500kw.

So far we've used something like 300 litres of oil since Oct 1st for both heating and hot water (no immersion, no electric showers, no stove).

1 litre of oil is 10kw assuming 100% efficient boiler, mine is 94%.

Therefore 1 litre of oil is 9.4kw.

300 litres is: 2820 kw.

Hot water conservatively accounts for 1/3 of that so our heating requirement to date is 1880kw.

We are approx. 3 months into the heating season for our home (mid Oct - April 1st), approx half way.

So double the "to date" usage gives 3760kw.

My actual heating need (3760kw) therefore are approx. half the amount they claim (7500kw)

BryanF

badgerhowlin wrote: »

Hi,
I found this and was wanting to know if its accurate or not.

http://www.passivehouseandhome.com/Passiveenergycosts.html

Its saying that an A3 rated house costs €7.50 to heat 1 m2 per year

I have a HP installed and want to know how much the HP is saving me so i can actually save that amount. Not looking for 100% correct info, just ball park.

Have you carried out a provisional BER or phpp. Your assessor/arch could offer an opinion on this

badgerhowlin

BryanF wrote: »

Have you carried out a provisional BER or phpp. Your assessor/arch could offer an opinion on this

I knew someone would come back with that answer

I have done one but he never told me. I have sent him an email but nothing back from him yet.

badgerhowlin

sas wrote: »

Those figures look very very high to me.

I'm A2, 300m2.

According to them it should take €3.75 per m2, or 25kw per m2 per year.

For my home that would be 7500kw.

So far we've used something like 300 litres of oil since Oct 1st for both heating and hot water (no immersion, no electric showers, no stove).

1 litre of oil is 10kw assuming 100% efficient boiler, mine is 94%.

Therefore 1 litre of oil is 9.4kw.

300 litres is: 2820 kw.

Hot water conservatively accounts for 1/3 of that so our heating requirement to date is 1880kw.

We are approx. 3 months into the heating season for our home (mid Oct - April 1st), approx half way.

So double the "to date" usage gives 3760kw.

My actual heating need (3760kw) therefore are approx. half the amount they claim (7500kw)

intresting. Wonder if anyone else has that to say about the figures they have put forward.

dathi

the only way to know for sure is to meter your electricity usage for your hp and compare it with the actual delivered kwh .none of the programs can take consumer usage patterns into account . ie you could build exact same house as sas and have different kwh usage simply by having the thermostats set at different temps.

badgerhowlin

Monitoring HP usage Daily so i know excetlly how much im using.
but where would i find "Actual delivered kwh" my BER assessor.
He will prpbable tell me what i have found out on that web site.
My uasge is 54Kwh/m2/y -> for 208m2 house is 11232kwh
So @ €0.15kw = €1684.80

But as SAS has pointed out the chart is off buy about 50% for him.

I guess what im asking IS this chart with in an asses ball of been correct?

starskey77

you got to get the correct depth of insulation in your attic, bay windows disaster
get walls pumped or your throwing money away

badgerhowlin

starskey77 wrote: »

you got to get the correct depth of insulation in your attic, bay windows disaster
get walls pumped or your throwing money away

Not sure how that is answering my Question,
BUT
400mm fiberglass in Attic and 120mm Rigid insulation in Walls along with 50mm Thermaliner (38mm insulation and 12mm plasterboard) on all external walls O and 100mm of rockwool in all internal walls and between ground and 1st floor.

Anyway this is not to talk about correct insulation levels. Its to see if the heating cost table that was on the passivehouseandhome.com is something you can take as a realistic costs for heating your home or are they WAY OFF

steifanc

My 13.5kw a/s/h.p uses about avg 14kwh per day , house is 300m2 underfloor , 80 tubes on the roof , heat recovery not working yet , and attic has only 200mm of rock wool down , not finished yet , on a long list of things to do . Walls have 200mm rockwool. With 80mm kingspan over it service cavity and 12.5mm slab .
Triple glazing .9 I think ,

fealeranger

badgerhowlin wrote: »

Monitoring HP usage Daily so i know excetlly how much im using.
but where would i find "Actual delivered kwh" my BER assessor.
He will prpbable tell me what i have found out on that web site.
My uasge is 54Kwh/m2/y -> for 208m2 house is 11232kwh
So @ €0.15kw = €1684.80

But as SAS has pointed out the chart is off buy about 50% for him.

I guess what im asking IS this chart with in an asses ball of been correct?

I'm no BER specialist but I doubt they have a chart just to keep people happy. There must be some calculations/variables missing or over looked. No organisation would put there name to a data chart that would not have merit, would they? Maybe get a different BER assesor on the case and see what that will yield.

sas

fealeranger wrote: »

I'm no BER specialist but I doubt they have a chart just to keep people happy. There must be some calculations/variables missing or over looked. No organisation would put there name to a data chart that would not have merit, would they? Maybe get a different BER assesor on the case and see what that will yield.

fealeranger wrote: »

I'm no BER specialist but I doubt they have a chart just to keep people happy. There must be some calculations/variables missing or over looked. No organisation would put there name to a data chart that would not have merit, would they? Maybe get a different BER assesor on the case and see what that will yield.

The figures are straight off the SEAI BER Cert info. chart.

I do recall a very long and heated debate on BER certs here. Ultimately the opinion of the professionals if I recall correctly is that while it's valuable as a comparison between 2 houses, it's not particularly good at predicting actual energy usage. My house pretty much proves this.

The PHPP is far more accurate at predicting performance.

My phpp is also much closer to my actual usage. It's predicting 11kw per m2 for heating which equates to 3300kw. My math above suggests I'll be approx 3760kw.

The PHPP defaults to 20 degrees. We prefer 21-22 in main living areas which would account for the increased usage over the designed amount.

I don't think I'm clear with what badgerh is trying to determine.

If I wanted to know how much a heat appliance was saving me, I'd:
- note the energy usage for the unit (in this case electricity)
- determine based on the specs for the appliance how much energy it provided (this will be kws determined based on hp efficiency)
- then with the provided energy, determine how much the other heat appliance would have cost for the same energy.

The Chart can state what it likes, the users dictate the comfort level required and hence the energy usage.

badgerhowlin

sas wrote: »

I don't think I'm clear with what badgerh is trying to determine.

The Chart can state what it likes, the users dictate the comfort level required and hence the energy usage.

It was mainly to see what people thought about the info that was on the website and was it anyway correct.
But it kind of took a turn to what i was going to save :rolleyes:

Dathi had suggested to me what you have said in your post

If I wanted to know how much a heat appliance was saving me, I'd:
- note the energy usage for the unit (in this case electricity)
- determine based on the specs for the appliance how much energy it provided (this will be kws determined based on hp efficiency)
- then with the provided energy, determine how much the other heat appliance would have cost for the same energy.

With some of your input and some pointers from dathi I have come up with some kind of a figure that im more or less happy with.
House will probable use about 10413kwh to heat house. which for me is close to what the website said i would need But since this is the 1st year im in the house im sure that will go down once i get the hang of my HP settings.

fealeranger

sas wrote: »

The figures are straight off the SEAI BER Cert info. chart.

I do recall a very long and heated debate on BER certs here. Ultimately the opinion of the professionals if I recall correctly is that while it's valuable as a comparison between 2 houses, it's not particularly good at predicting actual energy usage. My house pretty much proves this.

The PHPP is far more accurate at predicting performance.

My phpp is also much closer to my actual usage. It's predicting 11kw per m2 for heating which equates to 3300kw. My math above suggests I'll be approx 3760kw.

The PHPP defaults to 20 degrees. We prefer 21-22 in main living areas which would account for the increased usage over the designed amount.

I don't think I'm clear with what badgerh is trying to determine.

If I wanted to know how much a heat appliance was saving me, I'd:
- note the energy usage for the unit (in this case electricity)
- determine based on the specs for the appliance how much energy it provided (this will be kws determined based on hp efficiency)
- then with the provided energy, determine how much the other heat appliance would have cost for the same energy.

The Chart can state what it likes, the users dictate the comfort level required and hence the energy usage.

Like I said I am no specialist. I am not for or against BER certification. Unfortunatly it is a building regulation now and it has to be done. It does let a person know that the house is insulated and built to reach a certain standard which is good. One experience I learned while doing a self build is not everything on paper is correct. I still can't comprehend that a Chart of this level can be 50% off. The BER is there because it is a proven method to energy rate your house. If this is all confirmed and BER is not performing what will be the next step?

badgerhowlin

from my figures(which I can grantee you are not 100% correct) I have worked out that they are using an oil burner of about 52% COP. But with SAS's 1st post it looks plausible they are.

dathi

like i already posted the ber can not take consumer usage patterns into account it is there as a rough guide to energy requirements of a house to enable purchasers to compare several similar houses, and to show compliance with partL of building regs . the actual energy usage of a building is down to the habits of the owner .

homewardbound11

I am coming in at almost the same. 18 months into a 300m2 house with a2 rating. I must recheck the ber heat demand calculations but I too have oil but also 1 wood burning stove and solar. Total annual oil consumpition is averaging 350 euros.

badgerhowlin wrote: »

intresting. Wonder if anyone else has that to say about the figures they have put forward.