Central Heating

Hi

I'm hoping that I can get some advice regarding central heating for our home. The houe is currently run on oil central heating but we were thinking of switching to air to water system. The house is 3500 sq feet and we have 18 rads. A guy in work tells me that air to water is only suitable for under floor heating and might not work so well with so many rads.

When I said this to the rep from the company that quoted us for the air to water system he said that it would work fine and we would have no problem heating a house that size. We also need new rads so he suggested that we go with aluminim rads.

Can anyone please advise if we sould go with the proposed air to water system or maybe suggest a system that may work well for us.

The house is well insulated as it's drylined and we have just had cavity wall insulation done too.

radiators generally need input heated water at a temp of 60-70 deg to get a room up to 20 - 21 deg ambient temp.....
UFH only needs to get rooms to about 19 deg to give the same ambient comfort (hard to understand but true)... and is normally fed by heated water at 50-55 deg..... heat pumps are very efficient at reaching these temperatures, but may not be either able, nor efficient at reaching higher temperatures.....

to be honest i wouldnt be going on the word of a rep from the company, he has vested interested clearly...... its a huge expense to go to, so i would look for as many different opinions as possible.

if you are willing to put a grand into testing i would hire an energy company to do an air tightness test and write up an energy report for you with recommendations. If you dwelling gets a result of greater than 10, then id look at making provisions to get the dwelling envelope more air tight. I would also incorprate a HRV system.. i never like to see passive vents with a heat pump system.....

BeanoMc said:

The house is 3500 sq feet and we have 18 rads.

The house is well insulated as it's drylined and we have just had cavity wall insulation done too.

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If the issue bringing this up is the cost of oil to run the heating for the hosue perhaps you need to look at your control system and habits.

If at the moment you just have a clock to turn on and off the heating together with a manual system of turning off and on rads in certain rooms, you would save quite a lot in oil and running costs with some proper temperature/time controlled/zone equipment and of course new rads.

With 3500 sq feet a €1000 euro invested in controls now, even with the old rads, should lead to savings and more importantly improved comfort. Describe the age of the house, contruction type (double row block cavity or 9" cavity block), insulation if any behind dry lining, two storey/single storey, house age. Ceiling height. Occupancy all day/evening only etc etc.

If you talking about investing in an air to water heat pump ask the company supplying it to give you a site visit to a house of similar size to yours and while there ask to see a copy of their most recent ESB bill. It's unlikely they will have an install in a house with your level of insulation (which in todays world may be quite low) but you will get the idea.