Did you refer to the Irish websites for information? all the basic information is there.
I would think you need to discuss with your financial institution and the Irish tax office to confirm your residence and possible application to get a refund.
The tax is deducted by the bank or other deposit-taker before the interest is paid to you. If you request it, you are entitled to be given a statement of the amount of DIRT deducted from your interest. If you receive annual interest payments (or similar profit-type payments) of over €300 your bank, building society, credit union or An Post must automatically report this to Revenue.
DIRT is a final liability for income tax purposes. This means that if you have paid DIRT you do not have to pay any further income tax or Universal Social Charge on the interest, but it is declared as income if you are making a tax return. However, in some circumstances, you may have to pay PRSI on deposit interest you have received.
DIRT does not apply to interest on deposits owned by:
Companies that are liable to corporation tax
People not resident for tax in Ireland (see also below)
Revenue-approved pension schemes
If you are not resident in Ireland for tax, you may get a refund of any Deposit Interest Retention Tax deducted from your Irish deposit interest. To get a refund of DIRT, Ireland must have a double taxation agreement with the country you are resident in. DIRT will be refunded under the terms of that agreement. Fill in IC5 form (pdf) to apply for a refund of DIRT.
If you are not resident in Ireland, you may get your Irish deposit interest paid without the deduction of DIRT. A non-resident person does not have to be a resident of a country that has a double taxation agreement with Ireland to apply for a DIRT exemption. You should contact your financial institution to find out if you can be exempt from paying DIRT. You will have to complete a Non-Residence Declaration. You must notify them if you become resident again.