Condenser boiler or heat pump

[Haille]

I got 16 panels plus two 5kw batteries installed a year ago in a 1989 dormer bungalow.

Recently I got the walls pumped with bead insulation and attic insulation.

I have a 35 year old oil burner that is still going well. The plumber that put it in told me the lifespan of condenser boiler could possibly be 15 years. I paid 280 for a BER cert for panels last August. If I wish to claim the insulation grant I have to get another BER cert. I thought if I upgraded my boiler to a condenser boiler and installed a few thermostats for rads I would qualify for 700 euros heating upgrade grant and get the one BER cert to cover insulation and heating upgrade.

My question is would it be better to go for a heat pump? Though it is a 1989 house with no underfloor insulation so not sure if a heat pump would work as I assumed it requires max. insulation to make it viable? any thoughts?

 

[Zenith63]

To get the SEAI grant for a heatpump you’ll need to have a heatpump technical assessment done, which will give you a good sense of whether the levels of insulation, windows etc are sufficient for a heatpump to make sense. The only thing to watch out for is they pay zero attention to air tightness, so if you find the house drafty (very common in Irish dormers because of how they tend to be built!) you need to factor that into the results you get back from the assessment.

Regarding the solar PV, bear in mind your heatpump will mostly be running in the winter and during the night in the summer (to make use of the night rate), the two times when your solar panels generate very little.

 

[_OkGo_]

My question is would it be better to go for a heat pump?

I have a 35 year old oil burner that is still going well

If your oil burner is 35 years old, then I assume your radiators are equally as old?? If they are then they are more than likely not suitable for a Heat pump. You need to have low temperature radiators or underfloor heating that transfer the heat at much lower temperatures.

I assumed it requires max. insulation to make it viable? any thoughts?

Not necessarily, good insulation is very helpful but probably more important is the air tightness of the house. If you have lots of draughts then it may not be airtight.

If your home has always cooled down very quickly as soon as the heating is turned off then you probably have a leaky house that is not airtight and not currently suitable for a HP.

 

[Leo]

It really comes down to an assessment on whether the heat pump would be cheaper to run in the long term.

You'll need to factor in how much it will cost to switch and how much it will cost to run versus how much are you spending on oil now. Bear in mind heat pump systems are not as responsive as boilers, and so need to run longer to provide the same level of heating.

 

[conor_mc]

As alluded to by a couple of other posters, insulation and even air tightness are both significantly less important to heat pump efficiency than appropriate sizing of the overall heating system (i.e. pipe diameters, radiator sizes) so that the system can run at a low flow temperature (35-45 degrees) and still overcome the heat loss through the building fabric. As one heat pump engineer said, "they use heat pumps to heat marquees for goodness sake!" - it all comes down to heat energy in equaling heat energy lost, and doing that at as low a flow temperature as possible. In terms of running costs, you can assume an appropriately designed system will run at a coefficient of performance of at least 3.5, sometimes up to 4.5, so if your electricity price is less than 3.5 times the price per kwh of gas/oil it'll be cheaper.... generally electricity is around 3x the price of gas at the moment so not a huge saving, but generally results in a more comfortable home as heat is maintained rather than boiler off/temp drops followed by boiler on/temp rises. Strongly suggest checking out the Heat Geek consumer series on YouTube.

 

[Leo]

so if your electricity price is less than 3.5 times the price per kwh of gas/oil it'll be cheaper....

Most heat pump systems here seem to be specified on the assumption that they will run for much longer periods to compensate for the lower running temps and slower response times. While high-temp heat pumps are available, I don't see them referenced too often.

 

[AJAM]

I have solar panels and switched from a (new and relatively efficient) gas boiler to a Heat Pump.
My annual gas bill of 850 euro has disappeared.
My electricity bill has gone up by about 400 euro.
So I'm saving roughly 400 to 500 euro per year from switching to a Heat Pump.

 

[AJAM]

I will eventually add a Home Battery, which should enable me to run the heat pump almost entirely on cheap rate electricity.
This would mean the annual cost to run the heat pump would be closer to 150 euro.
Making the saving somewhere around 700 euro. But whether you count that as heat pump savings or battery savings, I don't know.

My philosophy on it, is that Electrification is actually an Ecosystem. Solar Panels, EV's, Heat Pumps and Batteries - each of them magnify the savings of the others. E.g. Solar Panels and Heat Pumps, there are large portions of the year, where during the day, my panels cover all the electricity for the Heat Pump. But even in Dec/Jan when they do not, the heat pump uses all the solar generation, which means I get the full value (35c) of my solar generation vs the 22c when you export it.

 

[conor_mc]

I have solar panels and switched from a (new and relatively efficient) gas boiler to a Heat Pump.
My annual gas bill of 850 euro has disappeared.
My electricity bill has gone up by about 400 euro.
So I'm saving roughly 400 to 500 euro per year from switching to a Heat Pump.

I have solar panels and switched from a (new and relatively efficient) gas boiler to a Heat Pump.
My annual gas bill of 850 euro has disappeared.
My electricity bill has gone up by about 400 euro.
So I'm saving roughly 400 to 500 euro per year from switching to a Heat Pump.

That’s a great result. Mind if I ask about the building structure/fabric?

 

[AJAM]

That’s a great result. Mind if I ask about the building structure/fabric?

New Double glazed windows (U Value 1.4)
Walls insulated with 50mm PIR insulation (U value 0.3)
Floor insulated with 75mm PIR
Roof insulated with 300mm or 400mm of earthwool

For the Heat Pump I had to upgrade 1 radiator as well as the hot water tank and the pipes.