What a disaster @Debs64 - you've just put the fear of god into me, as we've just cleared most of the house in the expectation of the carpet people turning up in the morning!
I thought from looking at the stuff on the web re heat pumps that although they can use existing radiators, they need more surface area as the water is heated to a much lower temperature
True. But in a new build which is designed for the heat pump that's not an issue. In an old house, it's a matter of degree (excuse the pun). Most rads are oversized. Most houses built in the last 20 years will be reasonably OK. Older houses will probably have to do some draught proofing, maybe replace windows and add loft insulation to get the heat loss down so the radiators are big enough. Underfloor heating is a choice. I do have it but most new heat pump homes have standard radiators.
I thought heat pumps can't currently hit what most people have their hot water set to (mine is currently between 50-60 degrees).
Not true. They can heat to those temps but it reduces the efficiency. Which isn't a problem for a short blast to heat up a tank of water from time to time. But if you run it all the time at that temperature to do your heating, the energy consumption will increase. Not to as much as an electric radiator but a much bigger fraction.
the houses have to be all but hermetically sealed (good for Covid eh?!). ....What about people who actually like having windows open - but still being warm!?
Completely untrue. Having a house that isn't draughty isn't 'hermetically sealed' and doesn't stop you opening the windows when you want to.
That's fine for new builds where the building standards are higher and insulation levels are high, but what is the impact on older properties?
As I said, older houses will probably have to do some draught proofing, maybe replace windows and add loft insulation. Some will need to add insulation to the walls - that's trickier and can be done very badly but it can be fine if the person doing it knows what they're about.
So we're going electric and moving on from gas - but that's then a double whammy on the grid - not only replacing fossil fuel cars, but moving from gas to electric for home heating in an overlapping time period.
And adding lots of renewable generation at the wrong end of the wires. There's no doubt there's a lot of work needed.
Don't get me wrong, I'm not against cleaning all the emissions up. What I think I dislike is what appears to be the '...just do it...the market will sort out the mess...' type method of planning how to clean it up.
Almost certainly, your local authority don't believe this and they are trying to change it. At the moment the government are actively making it harder for them. Despite all his fine words, Bojo and his mates are on the side of the developers who don't want to do it. They are all hoping that hydrogen will save the day. It really, definitely will not
Gardening on the edge of Exmoor, in Devon
“It's still magic even if you know how it's done.”
the houses have to be all but hermetically sealed (good for Covid eh?!). ....What about people who actually like having windows open - but still being warm!?
Completely untrue. Having a house that isn't draughty isn't 'hermetically sealed' and doesn't stop you opening the windows when you want to.
The confusion here is normally between a heat pump and a mechanical ventilation with heat recovery (MVHR) system. The MVHR requires a much better level of air tightness in a building to work properly but a heat pump with radiators just works like a normal boiler. MVHR is great for places where opening the windows isn't ideal due to noise or pollution.
If you can keep your head, while those around you are losing theirs, you may not have grasped the seriousness of the situation.
Building regulations require that in most homes you have to extract air from bathrooms and kitchens to stop damp and mould. When you suck that air out, air to replace what you take out has to come in from outside. In winter, that replacement air is potentially very cold, so you have to have a bigger heating system to heat up that cold air. MVHR is a system that warms up that air using heat from the air you are extracting from the bathroom, so it reduces how much heat is needed. That's all it does. Better air tightness reduces draughts and condensation. MVHR doesn't NEED better air tightness to work, but if you want to maximise the benefit, you should reduce air leakage. An MVHR won't replace opening the window when it's hot. It just provides the minimum amount of air you need to stop your house being (and smelling) damp in the winter.
And you're quite right, WE, it's entirely separate to the heat pump. Either works without the other. Both work better if you use them together
Gardening on the edge of Exmoor, in Devon
“It's still magic even if you know how it's done.”
My big concern about recharging cars is, we have frequent power outages here as it is. They are supposed to have upgraded the local grid here a few years ago but we still get dropouts. So far there are only two houses here that have electric cars, but if we all have them unless they upgrade the power network it will be chaos. BTW we are in suburban N London, not the middle of nowhere.
Whilst we were away in London last week we noticed several different ways to recharge an electric vehicle. 1.Charging points at the fuel station. 2.An extension cord running through the window to the car parked in the street. 3.Plugged directly into a street light. Even if that is "legal" there are more cars parked than there are lampposts. We left our car at home and. used the excellent public transport system, why would you not?
Ground and air source heat pumps require a completely different view on how you heat properties - let alone how you provide domestic hot water.
Not really. In a new build it will basically be the same except there's a heat pump in the back garden instead of a boiler in the kitchen or wherever. It'll still have radiators. The main difference will be it'll need a hot water cylinder - a lot of developers have ditched them to save a couple of square feet of space.
How much ground does a ground source heat pump require in order to be able to provide heat and hot water to a house? My nephew is in a new build and the back garden is tiny.
Also, what is required in order to install this system in an existing property? Although we have a large garden, there is a large patio between the house and the accessible part of the garden (accessible in terms of being able to bury anything in?
Any requirement for replacement windows, wall and loft insulation will surely put these systems out of reach of many people.
Posts
Underfloor heating is a choice. I do have it but most new heat pump homes have standard radiators.
Not true. They can heat to those temps but it reduces the efficiency. Which isn't a problem for a short blast to heat up a tank of water from time to time. But if you run it all the time at that temperature to do your heating, the energy consumption will increase. Not to as much as an electric radiator but a much bigger fraction.
Completely untrue. Having a house that isn't draughty isn't 'hermetically sealed' and doesn't stop you opening the windows when you want to.
As I said, older houses will probably have to do some draught proofing, maybe replace windows and add loft insulation. Some will need to add insulation to the walls - that's trickier and can be done very badly but it can be fine if the person doing it knows what they're about.
And adding lots of renewable generation at the wrong end of the wires. There's no doubt there's a lot of work needed.
Almost certainly, your local authority don't believe this and they are trying to change it. At the moment the government are actively making it harder for them. Despite all his fine words, Bojo and his mates are on the side of the developers who don't want to do it. They are all hoping that hydrogen will save the day. It really, definitely will not
“It's still magic even if you know how it's done.”
MVHR is a system that warms up that air using heat from the air you are extracting from the bathroom, so it reduces how much heat is needed.
That's all it does. Better air tightness reduces draughts and condensation. MVHR doesn't NEED better air tightness to work, but if you want to maximise the benefit, you should reduce air leakage.
An MVHR won't replace opening the window when it's hot. It just provides the minimum amount of air you need to stop your house being (and smelling) damp in the winter.
And you're quite right, WE, it's entirely separate to the heat pump. Either works without the other. Both work better if you use them together
“It's still magic even if you know how it's done.”
1.Charging points at the fuel station.
2.An extension cord running through the window to the car parked in the street.
3.Plugged directly into a street light. Even if that is "legal" there are more cars parked than there are lampposts.
We left our car at home and. used the excellent public transport system, why would you not?