Air heat pumps

Helplesswoman

Good evening everyone, 
Please excuse me if this has been asked before, I tried to find info from previous posts without much success. 

We live in the countryside where there is no main gas service, we live on expensive bottles that last a couple of weeks by running the heating 1 hour in the morning and 2 hours in the evening during weekend and 2 hours in the evenings during week. 

We have been thinking about replacing the system for an air heat pump, but a couple of plumbers friends of my partner have advise is a bad idea because they actually don’t produce enough heat to warm up the house. 

Anyone with positive experiences related to the use of air heat pump? Reliable companies to use? 

I’m fed up of living in a cold house 💔

Nearlyold

How well insulated is your property? Air source heat pumps operate at lower temperatures in terms of how hot radiators etc will be, so don't work well in poorly insulated homes in terms of how warm you'll feel.

You also need to have no outstanding EPC standard insulation requirements in order to get the  Govt  £7k+ grant for an ASHP.

BarelySentientAI

Helplesswoman said:

but a couple of plumbers friends of my partner have advise is a bad idea because they actually don’t produce enough heat to warm up the house. 

They do, just in a different way.

You can't run them one or two hours at a time, they're designed to be left almost always on.

matt_drummer

I read so many comments from people in various places where they always come out with `heat pumps don't work in poorly insulated houses as they don't produce enough heat'

That is not true.

Any property requires the same amount of heat to maintain a temperature whatever the heat source.

Poorly insulated homes will always require more heat whatever the heat source compared to if the insulation was improved.

The bit that not many people understand is that heat pumps are most efficient at very low flow temperatures but that does not mean that they don't produce lots of heat, they do.

If you want to run a heat pump efficiently and cost effectively then you need the right size heat pump running at low flow temperatures. It just has to provide enough heat to maintain the desired temperature, they do this with ease.

If the house is poorly insulated the you just need a bigger heat pump than you would if the insulation was better, you would lose less heat with better insulation and therefore require less energy from your heat source.

What you do need though to make it work are really large emitters, radiators and/or under floor heating.

Radiator output drops massively as the difference between the mean flow temperature and the room temperature get closer.

You just need really big radiators to get the same amount of heat that the heat pump likes to run at.

It is that simple, you get just as much heat at 30c flow as you do at 70c as long as the radiators are big enough and you flow enough water.

It is the loss of heat of the water flowing through the radiators that transfers heat to the house.

Try to imagine two scenarios, heating 1 litre of water from 0c to 100c or heating 10 litres of water from 0c to 10c. it takes the same amount of energy.

Cooling down water through radiators is the same, just in reverse.

That is how heat pumps work at low flow temperatures.

FreeBear

Nearlyold said: You also need to have no outstanding EPC standard insulation requirements in order to get the  Govt  £7k+ grant for an ASHP.

The requirement for EPC recommended insulation upgrades was dropped at the beginning of May, so more people should qualify for the £7500 grant.

Regardless of the source of heating, improving insulation levels where possible/practical is always a good idea. As is plugging all those nasty cold draughts.

Swipe

There are loads of post to read though in the heat pump forum https://forums.moneysavingexpert.com/categories/heat-pumps

matelodave

There are plenty of people on these forums who have heatpumps and are more than satisfied with them and even more who havent got one but know how bad they think they are.

However as @matt_drummer says, properly specified, installed commissioned and operated they can heat anywhere although as in any sort of heating, decent insulation means you'll need less heat and it will cost less to run. We've had a heat pump for 14 years (before they became the thing to have) and are more than happy with it.

check out the heatpump thread that @swipe has highlighted

MSE_ForumTeam5

We've moved this thread to the dedicated board for heat pump questions

Baxter100

matt_drummer said:

I read so many comments from people in various places where they always come out with `heat pumps don't work in poorly insulated houses as they don't produce enough heat'

That is not true.

Any property requires the same amount of heat to maintain a temperature whatever the heat source.

Poorly insulated homes will always require more heat whatever the heat source compared to if the insulation was improved.

The bit that not many people understand is that heat pumps are most efficient at very low flow temperatures but that does not mean that they don't produce lots of heat, they do.

If you want to run a heat pump efficiently and cost effectively then you need the right size heat pump running at low flow temperatures. It just has to provide enough heat to maintain the desired temperature, they do this with ease.

If the house is poorly insulated the you just need a bigger heat pump than you would if the insulation was better, you would lose less heat with better insulation and therefore require less energy from your heat source.

What you do need though to make it work are really large emitters, radiators and/or under floor heating.

Radiator output drops massively as the difference between the mean flow temperature and the room temperature get closer.

You just need really big radiators to get the same amount of heat that the heat pump likes to run at.

It is that simple, you get just as much heat at 30c flow as you do at 70c as long as the radiators are big enough and you flow enough water.

It is the loss of heat of the water flowing through the radiators that transfers heat to the house.

Try to imagine two scenarios, heating 1 litre of water from 0c to 100c or heating 10 litres of water from 0c to 10c. it takes the same amount of energy.

Cooling down water through radiators is the same, just in reverse.

That is how heat pumps work at low flow temperatures.

I think you've taken these comments too literally. When people say they 'don't work' they mean from a financial/practical perspective, not from a literal 'would never heat the house' point of view.

Yes of course if you install a big enough heat pump, big enough pipework and install big enough radiators, a heat pump will always be able to adequately heat a house. But at what cost? With what level of disruption? Are there better alternatives?

I could fit 10,000 incandescent light bulbs into a house and that would be able to provide all the heat requirements. Technically this would 'work', but its clearly a stupid idea.

tacpot12

There is a problem that unscrupulous firms claim that heat pumps will save you money. If you live in the countryside and keep the house well heated, possibly because someone at home has an illness and can't cope if they are cold, then a well installed heat-pump might save you money, but while the cost of electricity remains high, they are not likely to save enough money to justify their cost. However, the government grant alters the capital cost of installing a heat pump, so that they make more financial sense in certain situations, but you still need to look at the numbers carefully.  

You should look for a Heat Geek Find a Heat Geek - HeatGeek to give you a realistic idea of the cost to install a heat pump in your property, and what the running costs are likely to be. 

matt_drummer

Baxter100 said:

matt_drummer said:

I read so many comments from people in various places where they always come out with `heat pumps don't work in poorly insulated houses as they don't produce enough heat'

That is not true.

Any property requires the same amount of heat to maintain a temperature whatever the heat source.

Poorly insulated homes will always require more heat whatever the heat source compared to if the insulation was improved.

The bit that not many people understand is that heat pumps are most efficient at very low flow temperatures but that does not mean that they don't produce lots of heat, they do.

If you want to run a heat pump efficiently and cost effectively then you need the right size heat pump running at low flow temperatures. It just has to provide enough heat to maintain the desired temperature, they do this with ease.

If the house is poorly insulated the you just need a bigger heat pump than you would if the insulation was better, you would lose less heat with better insulation and therefore require less energy from your heat source.

What you do need though to make it work are really large emitters, radiators and/or under floor heating.

Radiator output drops massively as the difference between the mean flow temperature and the room temperature get closer.

You just need really big radiators to get the same amount of heat that the heat pump likes to run at.

It is that simple, you get just as much heat at 30c flow as you do at 70c as long as the radiators are big enough and you flow enough water.

It is the loss of heat of the water flowing through the radiators that transfers heat to the house.

Try to imagine two scenarios, heating 1 litre of water from 0c to 100c or heating 10 litres of water from 0c to 10c. it takes the same amount of energy.

Cooling down water through radiators is the same, just in reverse.

That is how heat pumps work at low flow temperatures.

I think you've taken these comments too literally. When people say they 'don't work' they mean from a financial/practical perspective, not from a literal 'would never heat the house' point of view.

Yes of course if you install a big enough heat pump, big enough pipework and install big enough radiators, a heat pump will always be able to adequately heat a house. But at what cost? With what level of disruption? Are there better alternatives?

I could fit 10,000 incandescent light bulbs into a house and that would be able to provide all the heat requirements. Technically this would 'work', but its clearly a stupid idea.

Really helpful, thanks!

Read what the OP said, they have been told by plumbers they know that heat pumps do not produce enough heat to warm up the house.

It seems pretty clear to me what they have been told?

Lots and lots of people think that water at 30c cannot provide enough heat , they think water needs to be hotter. My heat pump runs at 31c even when below freezing outside and my house is 22c+ indoors all the time

Many people also say that it is impossible to extract `heat' from air that is 0c or less. They don't understand that 0c is just the freezing point of pure water, it isn't a complete absence of energy.


Are there better alternatives? Burn stuff? Electric heaters at 100% efficiency?


That isn't what the OP asked.