Solar system from new house

Glenman

We are building at the moment and we received the following solar spec from our engineer "In order for your dwelling house to comply with Part L at least 10kWh/m2/yr of the required energy has to be renewable. This equates for solar panels to be used having an aperture area of 8.352m2. The aperture area of one Grant Sahara panel is 2.088m2, this means that 4 panels are required. This will equate to 9.44kWh/m2/yr, the wood stove secondary heating system will combine with the solar system to give a total of 11.43kWh/m2/yr. The capacity of the cylinder shall be 400litres and shall have 200litres dedicated to solar storage volume"

All of the plumbers that have priced the job so far say that this is too much for any house, the recommend 3 solar panels and a 300l cyl. They say that such a large cyl will reduce the efficiency of your stove. What do you suggest? Do I definately have to comply with the spec or is there any way around it? Thanks :-)

How many of the ThermoDynamic panels would I need to comply to our spec?

Froststop

Glenman wrote: »

We are building at the moment and we received the following solar spec from our engineer "In order for your dwelling house to comply with Part L at least 10kWh/m2/yr of the required energy has to be renewable. This equates for solar panels to be used having an aperture area of 8.352m2. The aperture area of one Grant Sahara panel is 2.088m2, this means that 4 panels are required. This will equate to 9.44kWh/m2/yr, the wood stove secondary heating system will combine with the solar system to give a total of 11.43kWh/m2/yr. The capacity of the cylinder shall be 400litres and shall have 200litres dedicated to solar storage volume"

All of the plumbers that have priced the job so far say that this is too much for any house, the recommend 3 solar panels and a 300l cyl. They say that such a large cyl will reduce the efficiency of your stove. What do you suggest? Do I definately have to comply with the spec or is there any way around it? Thanks :-)

How many of the ThermoDynamic panels would I need to comply to our spec?

I'm unsure about thermodynamic qualifying as the Seai don't recognise it as far as I know, I may be corrected.
However 1 Thermo panel would do up to 300-400 litres.

freddyuk

kWh per m2 per year is not the same as Aperture area is it? I understood this refers to the floor area of the building? Are you mixing up the energy factors?
What is the floor area of the building?
I am no expert just seems wires are crossed.

shane0007

You will need to meet Part L of the Building Regs.

If you can post the exact m2 of the house, a link to a datasheet for the solar panel and exact make & model of the cylinder to be used, I can calculate the exact size required to meet Part L. You can also install a wood burning stove to assist in contributing to Part L. Multi-fuel stoves do not count.

Aperture area is the aperture area of the panel. The kwh/m2 is the contribution of the panel to the home per m2.

ccsolar

Froststop wrote: »

I'm unsure about thermodynamic qualifying as the Seai don't recognise it as far as I know, I may be corrected.
However 1 Thermo panel would do up to 300-400 litres.

Thermodynamic solar will make no renewable energy contribution to this house as required by part L
Cc

ccsolar

Glenman wrote: »

We are building at the moment and we received the following solar spec from our engineer "In order for your dwelling house to comply with Part L at least 10kWh/m2/yr of the required energy has to be renewable. This equates for solar panels to be used having an aperture area of 8.352m2. The aperture area of one Grant Sahara panel is 2.088m2, this means that 4 panels are required. This will equate to 9.44kWh/m2/yr, the wood stove secondary heating system will combine with the solar system to give a total of 11.43kWh/m2/yr. The capacity of the cylinder shall be 400litres and shall have 200litres dedicated to solar storage volume"

All of the plumbers that have priced the job so far say that this is too much for any house, the recommend 3 solar panels and a 300l cyl. They say that such a large cyl will reduce the efficiency of your stove. What do you suggest? Do I definately have to comply with the spec or is there any way around it? Thanks :-)

How many of the ThermoDynamic panels would I need to comply to our spec?

Hi
The 4 panel 400 litre system is a great system to have installed, and you won't be sorry as the saving on oil will help to cover the extra cost of the 4 th panel.
If the stove been fitted is a good quality one then you should have no problems with the efficiency, we have fitted several stoves onto 500 litre tanks.
Your engineer needs to check his dedicated solar volume again as I would calculate it at 300+ litres and the seai would normally allow you to put down a figure of 350 litres as the solar heats the tank from the bottom up..
You might also want to consider the 4 flat panel 300 litre tank as this size system will give you great results in the winter months.
Who recommended a 400 litre tank as this size is an odd size tank and costs almost as much as a 500 litre tank, 300 and 500 litre tanks are off the shelf and if you deviate from these sizes it's €€€€
You should be looking at a bill of €5500 for the 4 panel system fully fitted, any more and your paying for someone's summer holiday.
Cc

magsie_99

Hi,

(first time posting to Boards so forgive me if I dont make sense)

I'm in the same boat as Glenman and my house is going to be 2600sq feet. I've been advised that if I go with an oil heating system (oil boiler with rads) I will have to install:-
>A certified wood burning only stove
>A value better than 0.25 on completion of air leakage test (an air leakage test has to be carried out once the dwelling house is finished)
>The solar panels on their own will not meet regulations in terms of providing a % renewable energies. Its recommended I install a 2.5kWp PV solar system which is similar to solar only instead of generating hot water it generates electricity which you can sell back to the national grid. The cost of this unit is approximately 7K.

This sounds very expensive.

any other ideas
so i have a keen interest in this post

dathi

ccsolar wrote: »

Hi

Your engineer needs to check his dedicated solar volume again as I would calculate it at 300+ litres and the seai would normally allow you to put down a figure of 350 litres as the solar heats the tank from the bottom up..
You might also want to consider the 4 flat panel 300 litre tank as this size system will give you great resul
Cc

the dedicated solar volume is clearly stated in the seai bulletins as the volume of water in the space occupied by the solar coil and not the total volume of water sitting above the coil.

shane0007

dathi wrote: »

the dedicated solar volume is clearly stated in the seai bulletins as the volume of water in the space occupied by the solar coil and not the total volume of water sitting above the coil.

Very true.
If you cannot obtain the actual dedicated volume from the cylinder manufacturer's data sheet, you can take it as one third of the total cylinder volume.

So a 300 litre cylinder would have a dedicated solar volume of 100 litres.
A Joule stainless steel 300 litre cylinder has a dedicated volume of 165 litres.

dathi

you can also measure the inlet and outlet heights of the solar coil and use that to work out the volume as% of total height of cylinder

ccsolar

shane0007 wrote: »

So a 300 litre cylinder would have a dedicated solar volume of 100 litres.
A Joule stainless steel 300 litre cylinder has a dedicated volume of 165 litres.

Ive yet to find a Joule 300 litre cylinder that actually holds 300 litres, just because it says 300 litres on the sticker doesn't me it actually holds 300 litres.
Ive had engineers do the calculations of the actual cylinder dimensions and found the actual volume of water within the cylinder is less than 300 litres.
Calculation was carried out in 2012.
Joule 300 litre cylinder dimensions 1535mm H x 560mm W = 300 Litres
Warmflow 300 litre cylinder dimensions 2077mm H x 550mm W = 290 Litres
The Joule cylinder is over half a metre shorter but holds more water than the Warmflow cylinder???? I don't think so.
Cc

ccsolar

dathi wrote: »

the dedicated solar volume is clearly stated in the seai bulletins as the volume of water in the space occupied by the solar coil and not the total volume of water sitting above the coil.

The seai calculator will automatically fill in the Dedicated solar volume for you on their calculator if you input 0.
Having had several conversations with the seai on this matter it's a general rule of Thumb that if your unsure of the Dedicated volume then they will except a 2/3 figure.
Cc

ccsolar

Glenman wrote: »

We are building at the moment and we received the following solar spec from our engineer "In order for your dwelling house to comply with Part L at least 10kWh/m2/yr of the required energy has to be renewable. This equates for solar panels to be used having an aperture area of 8.352m2. The aperture area of one Grant Sahara panel is 2.088m2, this means that 4 panels are required. This will equate to 9.44kWh/m2/yr, the wood stove secondary heating system will combine with the solar system to give a total of 11.43kWh/m2/yr. The capacity of the cylinder shall be 400litres and shall have 200litres dedicated to solar storage volume"

All of the plumbers that have priced the job so far say that this is too much for any house, the recommend 3 solar panels and a 300l cyl. They say that such a large cyl will reduce the efficiency of your stove. What do you suggest? Do I definately have to comply with the spec or is there any way around it? Thanks :-)

How many of the ThermoDynamic panels would I need to comply to our spec?

Hi Glenman
Ive attached 2 calculations for you to view using Grant and Joule 4 flat panels 400 Litre Tank and a 300 sqm house.
Hope this helps.
Cc

shane0007

ccsolar wrote: »

Ive yet to find a Joule 300 litre cylinder that actually holds 300 litres, just because it says 300 litres on the sticker doesn't me it actually holds 300 litres.
Ive had engineers do the calculations of the actual cylinder dimensions and found the actual volume of water within the cylinder is less than 300 litres.
Calculation was carried out in 2012.
Joule 300 litre cylinder dimensions 1535mm H x 560mm W = 300 Litres
Warmflow 300 litre cylinder dimensions 2077mm H x 550mm W = 290 Litres
The Joule cylinder is over half a metre shorter but holds more water than the Warmflow cylinder???? I don't think so.
Cc

Joule 300L twin coil cylinder volume is actually 235 litres less the volume of each coil.
When calculating the cylinder volume, you also need to deduct the thickness of the insulation which is 55mm each side & top.
So Pie x r2 x height
3.142 x (225 x 225) x 1480 = 235 litres. Then whatever each coil volume which is not in their technical data sheets. Their dedicated solar volume is a bit naughty also at 160 litres.

ccsolar

shane0007 wrote: »

Joule 300L twin coil cylinder volume is actually 235 litres less the volume of each coil.
When calculating the cylinder volume, you also need to deduct the thickness of the insulation which is 55mm each side & top.
So Pie x r2 x height
3.142 x (225 x 225) x 1480 = 235 litres. Then whatever ever coil volume which is not in their technical data sheets. Their dedicated solar volume is a bit naughty also at 160 litres.

Correct Shane
So why are they flogging it as a 300 litre?
Have you ever drilled a hole in the tank to check the insulation depth?
Cc

shane0007

ccsolar wrote: »

Correct Shane
So why are they flogging it as a 300 litre?

Because the smaller cylinder will fit into more hot presses & the customer has a cylinder with 300 litres written on it. The solar system performs much better because it is heating less volume, so the customer thinks the installer is the biz!
So, the installer is happy, the customer is happy & Joule sell more cylinders.

Many of their rivals are moaning about them but they have yet to be pulled about it. I suppose it would be a trading standards issue.

That said, they are an excellent quality cylinder. I have yet to have one fail on me.

ccsolar wrote: »

Have you ever drilled a hole in the tank to check the insulation depth?
Cc

I generally try not to, as I don't think the customer would pay my invoice if I were to drill a hole in the side of their newly installed cylinder :eek:

shane0007

It also does not say a lot for the Irish NSAI Certification as Joule's solar systems are NSAI certified which includes the use of their cylinder for the certified installation.

ccsolar

shane0007 wrote: »

Because the smaller cylinder will fit into more hot presses & the customer has a cylinder with 300 litres written on it. The solar system performs much better because it is heating less volume, so the customer thinks the installer is the biz!
So, the installer is happy, the customer is happy & Joule sell more cylinders.

Many of their rivals are moaning about them but they have yet to be pulled about it. I suppose it would be a trading standards issue.

That said, they are an excellent quality cylinder. I have yet to have one fail on

Thanks Shane
You have just wrote what I've been singing aloud for the last few years, even when joule used to buy the Telford tank the capacity was in question.
Cannot fault the quality but I have drilled a 3mm hole just to check the dept...
Cc

shane0007

ccsolar wrote: »

Thanks Shane
You have just wrote what I've been singing aloud for the last few years, even when joule used to buy the Telford tank the capacity was in question.
Cannot fault the quality but I have drilled a 3mm hole just to check the dept...
Cc

And what depth did you find?

Glenman

Thanks for all the replies, very helpful

fitzzy13

I want to build a 2000 to 2400 sq ft house. What heating system would you put in?

Wearb

fitzzy13 wrote: »

I want to build a 2000 to 2400 sq ft house. What heating system would you put in?

A couple of candles.

I say that because if I was starting again I would put in enough insulation to make sure it required very little heat. You DO have to weigh up the extra cost of insulation against cost of heating over your lifetime.
Do you have room for different sorts of geothermal? It seems to work well with underfloor heating.

I have a neighbour that has new build with a Grant wood pellet burner that he is very happy with, though there are lots of horror stories about them. I think the troublesome pellet ones are mostly down to very poor installation, so I would not rule them out at all.

Oil or gas isn't too expensive in a well insulated and well zoned and controlled house. There are newer technologies out there that I don't understand in enough detail to comment on, but I am sure you will get more replies.

I have a cousin in the states with a wind turbine in their back garden that supplies their needs and some income also.

Anyway there is some food for thought and keep talking to people you know that have had new houses for a couple of years with different types of heating.

fitzzy13

I do not know what to put in and what they cost. I was thinking maybe thermodynamic solar panels, a heat pump, and heat recovery system. My wife does not want under floor heating as she thinks it cost too much to run.

dathi

fitzzy13 wrote: »

I do not know what to put in and what they cost. I was thinking maybe thermodynamic solar panels, a heat pump, and heat recovery system. My wife does not want under floor heating as she thinks it cost too much to run.

(1) "thermodynamic solar panels" is a heat pump a striped down one that relies on air passing over the panel rather than using a fan to draw air through the coils.
(2) a heat pump works best when delivering low temperature water to under floor heating as the higher temps required for rads reduce the efficiency of the heat pump the "magical" COP figure used by heat pump suppliers is based on water temp of 35*
(3) heat recovery ventilation is probably a necessity at this stage to comply with part L of building regs

shane0007

Wearb wrote: »

A couple of candles.

I say that because if I was starting again I would put in enough insulation to make sure it required very little heat.

Don't forget that for health reasons the air must be changed a number of times per hour, so the candle must be able to reheat said air to maintain the comfort levels other halves demand!

Wearb

shane0007 wrote: »

Don't forget that for health reasons the air must be changed a number of times per hour, so the candle must be able to reheat said air to maintain the comfort levels other halves demand!

I got her a fleece blanket for Valentines. House seems very quiet since. I gave her the price of a bunch of flowers aswell. Still doesn't seem very pleased. I will never understand them

shane0007

I made my missus a lovely card. Spent ages on it with the computer. Even took my time folding it after I printed it. She's still not talking to me....