RVR Energy Technology in Kenmare provide a product called Magis Combo which appears to suit older homes.I'm not particular familiar with any specific systems on the market but high temperature heating systems (oil & gas fired) have been mimicking low temperature systems (heat pump) for decades and therefore it should be no issue to combine them once the logic/control system is properly thought through.
However the best approach, in my opinion, is to where feasible reduce the need for the heat in the first place by finding & addressing the low hanging heat loss fruit.
Will you enquire on the detail behind their claim that more than 90% of the heating required comes from the hp.I have arranged for site visit by RVR technology and will revert with outcome.
It would appear that their system is more akin to a hybrid car than having 2 cars but let me get the facts.
I think air tightness is number one in relation to heat loss, not insulation. The harder a heat pump has to work to maintain the required temperature the less economical it will be to run it. I've heard horror stories of heat pumps and how much they cost to run, usually due to not being right in the first place. My understanding is that it would take a lot of investment to make a heat pump work in an older house, where you have air leakage thru floors, doors, walls, ceilings etc. This is from reading anecdotal posts online as opposed to any great personal knowledge, education or experience.Agree with many of the thoughts here @bstop, i looked at hybrid v fully
electric cars last year, and concluded after a lot of reading and test drives, pricing, overall annual running costs, and driving experience etc, EV was the way to go.
Took the EV plunge, and have never looked back.
Similarly, i have been looking into heat pumps + replacing a 27 year old double glazed windows in recent months. We also currently have a 27 year old gas boiler.
Have had a few quotes, and late last year i was saying NO to a heat pump, as it did not seem to make financial sense, the heat pumps were in the 10 to 12k price bracket alone, this included replacements for a quarter of our existing radiators, as not all are suitable to work with heat pumps. So with the excessive cost, even after grants, i diverted course, onto looking at a new efficient condenser boiler and a full window/door replacement.
However the recently revised, and much increased grants, have changed all that, so i need to look over it all again.
What i did learn along the way about Heat Pumps, is they will only work efficiently, if your house is well insulated, as others have mentioned, get the low hanging fruit sorted out first, so that means getting attic insulation & walls pumped - we already have those two done, recently, any open chimneys ? we boxed that off with a stove replacing fireplace, and has already made a noticeable difference. Next, is windows & doors, which contribute significantly to heat loss. One of the window/door quotes has triple glazing with a uv value of 1, or double glazing with a little higher u value 1.4, I am leaning towards triple glazed as my understanding is, the lower u values will make the heat pump work more efficiently, and its also an opportunity to get better external noise reduction, with triple glazed. Apparently there is some solar gain loss, with triple glazed, as they apparently leave less sun heat into the house, i’m fine with that, as house can often, be too hot in summer months, as it is.
Also, i learned that heat pumps heat a house very slowly, so typically, are most efficient, when left run continuously, they will increase temperature as required, to a chosen temperture setting, then come on/off, to keep it at that temperture.
Water can be heated, independantly.
Do some reading up on it, there is a lot to take in, and its new’ish and different tech, and involves changing, how one does things. The more you research, the more you will understand it better, and be in a position to make a more informative choice, and minimise any “surprises”!
Tbh, until the house is tested you won't know but generally doors and windows can very often be the least of the issue. The main culprits are quite often the elemental junctions (for instance the junction between the floor and the wall) and cable / pipe penetrations of floor, roofs, walls including internal floors and walls.Interesting. So, assuming attic is fully insulated to current standard, external walls are pumped, low 1 u value triple glazed windows and doors installed, what else is there, to improve air tightness in an older house ?
Makes perfect sense.Do many people do an air leakage test?Should it be done before and after?Tbh, until the house is tested you won't know but generally doors and windows can very often be the least of the issue. The main culprits are quite often the elemental junctions (for instance the junction between the floor and the wall) and cable / pipe penetrations of floor, roofs, walls including internal floors and walls.
This can be very difficult to "get" until you experience the test for yourself and see / feel what is going on. The level of air leakage can also vary quite a bit between different house types / eras and also depending on what "improvements" have been done over time.
Adding / upgrading insulation in walls and attics rarely make any meaningful difference to a house with high air leakage because insulation addresses conductive heat loss whereas air tightening addresses convective losses (aka draughts).
Relying on a heat pump to supply the heat at the required rate to match the losses in a building with high air leakage is very risky in the absense of addressing the primary heat loss mechanisms first.
Before!. And ask Micks'r, he's an expert in this field.!Makes perfect sense.Do many people do an air leakage test?Should it be done before and after?
Would making the house airtight cause problems with condensation and black moldTbh, until the house is tested you won't know but generally doors and windows can very often be the least of the issue. The main culprits are quite often the elemental junctions (for instance the junction between the floor and the wall) and cable / pipe penetrations of floor, roofs, walls including internal floors and walls.
This can be very difficult to "get" until you experience the test for yourself and see / feel what is going on. The level of air leakage can also vary quite a bit between different house types / eras and also depending on what "improvements" have been done over time.
Adding / upgrading insulation in walls and attics rarely make any meaningful difference to a house with high air leakage because insulation addresses conductive heat loss whereas air tightening addresses convective losses (aka draughts).
Relying on a heat pump to supply the heat at the required rate to match the losses in a building with high air leakage is very risky in the absense of addressing the primary heat loss mechanisms first.
It absolutely can/will if not taken into account with an appropriate ventilation strategy or system. Air tightness needs to be balanced with ventilation otherwise issues will quickly arise and they can be severe.Would making the house airtight cause problems with condensation and black mold
If you are venterlating the house, you must have air in to replace it which will be cold air, so there is no such thing as a sealed houseIt absolutely can/will if not taken into account with an appropriate ventilation strategy or system. Air tightness needs to be balanced with ventilation otherwise issues will quickly arise and they can be severe.
When you consider that a typical family of 5 typically produce between 12 and 18 litres of water in the home per 24 hour period through normal activities of breathing, cooking, washing etc. This moisture is generally contained in the air and this "wet" air needs to be exchanged with "dry" external to maintain a dry house internally. When the house leaks a lot of air, i.e. is very draughty, this "wet" internal air is easily exchanged with the dry outside air. When the house is air tightened, appropriate ventilation will do this work when designed and used correctly.