Does ASHP work for older people on blood thinners?

[CalvinHobbes]

Here's the thing, we are having a granny annexe and bluntly mum requires intense heat since she is on blood thinners. We have spent 1k on oil in this leaky rented house since the start of the year. The areas she can't reach are a normal temp but for the new build the spec of an ashp is really worrying me. Not only that it has vaulted ceilings which I guess makes it worse. Yes we have 200mm PIR cavities and triple glazing but she needs fast heat. Not it to sloooooowly warm up in a day.

Yes , she is nearly 87 and won't be around forever but we plan to stay there so maybe I will face the issue myself in 20 years?

We met extended family yesterday and I was told how a couple who have moved into their new house deeply regret getting an ASHP since their electric bills have been breathtaking. Yes they know the fitter was incompetent but that doesn't help. There are so few here that are trained. To even get one serviced will be fun.

I was watching heat geek on you tube and there was a guy in the comments studying thermodynamics who said his course wasn't covering this stuff and it should. The poor guy who had a terrible experience with an ashp had the patience of a saint.

I owned a renault zoe a couple of years ago and now am back on diesel. I just get the feeling this might end up the same way and frankly it would be too expensive a mistake.

We got planning permission and the plans submitted did have an ashp included.  I wonder if we could change? That said that Qube house I showed you is now up for sale and it swapped from ashp to oil I see. (dropped in price) https://www.robertferris.co.uk/the-qube-passive-house-11-hazelwood-avenue-prehen-londonderry/902675

 

Edited March 31 by CalvinHobbes

[NailBiter]

There is no requirement for planning permission for any heating method other than ASHP (and even then only if you already have a wind turbine or a second ASHP fitted). Unless there is a planning condition specifically requiring the use of an ASHP what you decide to do is completely up to you.

I have driven a rental Renault Zoe and I can quite see how it could leave a bad taste. I've driven many EVs since and they are all much better. Many of them significantly better than any ICE vehicle. Don't let a crappy implementation put you off a good concept.

As for whether an ASHP is going to lead to high bills or a cold house there are too many variables for us to comment properly.

There is some real world data available here: https://heatpumpmonitor.org

 

1. Radiators (oversized?) or hydronic (wet) underfloor heating?
2. What is the overall U-rating of the building fabric including transparent elements?
3. What is the air-tightness of the building? Do you have an MVHR fitted? What is the controlled ACH (air changes / hr) you are aiming for?

4. How thick is your screed? Is it insulated underneath?
5. What size ASHP did you go for? How many m3 is it having to deal with?
6. Where is your electricity coming from? Solar? Wind? Grid? Can you get on a TOU (time of use) tariff and set your heating controller accordingly?

7. What is your control strategy? (e.g. get it up to 21 degrees and let it sit there, juice it with cheap TOU or renewable energy when you can.

Most of these considerations would apply regardless of if your source of heating was oil, gas or a heat pump using electricity to extract heat from the air.

You will be fine with a well designed and fitted ASHP. There are also safety issues with other fuel sources that don't apply to ASHPs.

If you are worried about being instantly able to change the heating you should take a look at infrared heaters. They respond almost instantly.
 

Edited March 31 by NailBiter

[Conor]

It'll work fine. Just get the ASHP and be done.

[joe90]

19 minutes ago, CalvinHobbes said:

she needs fast heat.

See

4 minutes ago, NailBiter said:

If you are worried about being instantly able to change the heating you should take a look at infrared heaters. They respond almost instantly.

Also I guess Granny is not going out much so will need heat 24/7 so

21 minutes ago, CalvinHobbes said:

Not it to sloooooowly warm up in a day.

I think most ASHP and UFH works on the principle of constant temps not neat up and cool down. Therefore a well designed ASHP system will work with additional Granny’s instant heating.

[CalvinHobbes]

11 minutes ago, NailBiter said:

There is no requirement for planning permission for any heating method other than ASHP (and even then only if you already have a wind turbine or a second ASHP fitted). Unless there is a planning condition specifically requiring the use of an ASHP what you decide to do is completely up to you.

I have driven a rental Renault Zoe and I can quite see how it could leave a bad taste. I've driven many EVs since and they are all much better. Many of them significantly better than any ICE vehicle. Don't let a crappy implementation put you off a good concept.

As for whether an ASHP is going to lead to high bills or a cold house there are too many variables for us to comment properly.

There is some real world data available here: https://heatpumpmonitor.org

 

1. Radiators (oversized?) or hydronic (wet) underfloor heating?
2. What is the overall U-rating of the building fabric including transparent elements?
3. What is the air-tightness of the building? Do you have an MVHR fitted? What is the controlled ACH (air changes / hr) you are aiming for?

4. How thick is your screed? Is it insulated underneath?
5. What size ASHP did you go for? How many m3 is it having to deal with?
6. Where is your electricity coming from? Solar? Wind? Grid? Can you get on a TOU (time of use) tariff and set your heating controller accordingly?

7. What is your control strategy? (e.g. get it up to 21 degrees and let it sit there, juice it with cheap TOU or renewable energy when you can.

Most of these considerations would apply regardless of if your source of heating was oil, gas or a heat pump using electricity to extract heat from the air.

You will be fine with a well designed and fitted ASHP. There are also safety issues with other fuel sources that don't apply to ASHPs.

If you are worried about being instantly able to change the heating you should take a look at infrared heaters. They respond almost instantly.
 

 

[HughF]

Our ashp can easily heat the place to 24 degrees…. It’s all about radiator sizing…

[joe90]

5 minutes ago, HughF said:

Our ashp can easily heat the place to 24 degrees…. It’s all about radiator sizing…

Yes, because ASHP,s heat slowly and at low temps they work in well insulated houses, where they fail IMO is where the heat loss of the house is greater than the input.

[HughF]

11 minutes ago, joe90 said:

Yes, because ASHP,s heat slowly and at low temps they work in well insulated houses, where they fail IMO is where the heat loss of the house is greater than the input.

1946 end of terrace on a hill, facing south west….

 

we had a 10kW gas boiler when we had single glazing. An ashp can easily heat any house.

 

Any heat source will fail when the heat loss is greater than the input, that’s basic physics.

[JohnMo]

1 hour ago, Conor said:

It'll work fine. Just get the ASHP and be done.

Exactly.

 

2 hours ago, CalvinHobbes said:

Not it to sloooooowly warm up in a day

You are building a passivhaus not a barn. Your temperature will not move more than a degree a day and that's without heating on. I am not passive and have the heating on overnight, temp doesn't vary more than 0.5 Deg until the heat comes on again.

 

Stop listening to people filling your head with nonsense. Two weeks ago you were asking if you needed heat in a passivhaus, then I need an oil boiler because the ventilation man said xyz, now you are fretting that you will not get enough heat. So as @Conor says.

[CalvinHobbes]

2 minutes ago, JohnMo said:

Exactly.

 

You are building a passivhaus not a barn. Your temperature will not move more than a degree a day and that's without heating on. I am not passive and have the heating on overnight, temp doesn't vary more than 0.5 Deg until the heat comes on again.

 

Stop listening to people filling your head with nonsense. Two weeks ago you were asking if you needed heat in a passivhaus, then I need an oil boiler because the ventilation man said xyz, now you are fretting that you will not get enough heat. So as @Conor says.

Mea culpa. I am fretting and it likely is stupid. That said, coming from the 'I haven't a clue' perspective it is terrifying. Right back to ashp. I must get that paperwork thingy off the architect that gives the heat loss calcs you all keep mentioning. Also at work and nothing much is happening so intensive building/ you tube going on with me going ah!!!!

[SteamyTea]

@CalvinHobbes

 

What room temperature are you trying to reach?  This is what determines your heat source.

You can if you want do a combination heating systems i.e. wet ASHP and an A2AHP.

 

I was at my Mother's Care home yesterday, noticed that there is a number of ASHPs on the building.  Had a little route about and it seems the place is heated with them, why the radiators do not seem hot, but they are near enough on all the time.

[JohnMo]

Trying to sort out fact from opinion is difficult. You need facts to be informed.

 

Something to read, my heat pump performance table for flow temp and outside temp, CoP and power needs.

 

 

What you see at flow temps below 35 CoP is good at almost any outside temp.

 

Another document that shows UFH output at different pipe centres and heat outputs at different mean flow temps. ASHP heat flow with delta T of 5 to 6, so the mean temperature is flow temp -2.5 to 3, when using table. W/m2 is highest heat demand, divided by the area of the floor.

 

 

[JoeBano]

Just looked at my costings for the winter season, £486 for hot water and heating since September. 1936 built

detached I’ve insulated, house sits at 21c. Over the moon with it. 

[Originaltwist]

34 minutes ago, JohnMo said:

Trying to sort out fact from opinion is difficult. You need facts to be informed.

Yes but you can prove anything with facts.

 

Seriously though, I love those charts, where do they come from?

[JohnMo]

2 minutes ago, Originaltwist said:

Seriously though, I love those charts, where do they come from?

The CoP heating temperature came from a Maxa heat pump technical manual. The UFH I found on the internet somewhere. But the figures seem ok, match LoopCad reasonable well.

[sharpener]

3 hours ago, CalvinHobbes said:

we are having a granny annexe and bluntly mum requires intense heat since she is on blood thinners

 

Not really an ASHP answer but is she on the latest kind (apixaban or edoxaban)? Feeling cold is not I think a common side-effect but thyroid problems are notorious, has she been checked for that?

[ProDave]

WHAT temperature does she need to be comfortable?

 

In a well insulated house, forget the concept of fast heat.  A properly well insulated house will keep it's heat for a very long time, so forget the old concept of turn the heating on in the morning (when you might well want it to heat quickly) and turn it off at bed time and let the house cool down overnight.

 

A well insulated house simply does not work like that.  It heats up and stays warm.  So just choose what temperature she wants and set it.  It does not matter if on first heat up it takes a while to get there.  It barely cools down any overnight so takes little time in the morning to heat up again.  Or just leave the ASHP running 24/7 just controlled by a thermostat.

[CalvinHobbes]

3 hours ago, sharpener said:

 

Not really an ASHP answer but is she on the latest kind (apixaban or edoxaban)? Feeling cold is not I think a common side-effect but thyroid problems are notorious, has she been checked for that?

She has been thanks. She is in constant atrial fibrillation so we are walking a tight rope with warfarin, bisoprolol, digoxin etc. Doing well though, quite happy, she just likes it about 23 degrees lol. I haven't the heart to turn it down. 

[CalvinHobbes]

2 hours ago, ProDave said:

WHAT temperature does she need to be comfortable?

 

In a well insulated house, forget the concept of fast heat.  A properly well insulated house will keep it's heat for a very long time, so forget the old concept of turn the heating on in the morning (when you might well want it to heat quickly) and turn it off at bed time and let the house cool down overnight.

 

A well insulated house simply does not work like that.  It heats up and stays warm.  So just choose what temperature she wants and set it.  It does not matter if on first heat up it takes a while to get there.  It barely cools down any overnight so takes little time in the morning to heat up again.  Or just leave the ASHP running 24/7 just controlled by a thermostat.

Yep, thanks will do. Her area will be zoned to be hot. 

[HughF]

1 minute ago, CalvinHobbes said:

Yep, thanks will do. Her area will be zoned to be hot. 

Do that by rad sizing, not by zoning or trvs… heat pumps like direct, open, systems.

[CalvinHobbes]

Right ok will ensure they are right. Good to know. Cheers 

[SteamyTea]

12 minutes ago, CalvinHobbes said:

about 23 degrees

Not excessively hot and well within the capabilities of all heat pumps.

 

Just a case of designing it correctly and making sure there are not too many losses though the fabric of the building.

[Garald]

Two options:

 

- Get a two-zone ASHP, with the granny annexe being one zone,

- Get an ASHP - and put a small electric radiator in the room (the least powerful you can find) for those times times when she wants an extra couple of degrees, fast. For all that I know, a towel-warmer may do.

Edited March 31 by Garald

[Kelvin]

18 hours ago, CalvinHobbes said:

Mea culpa. I am fretting and it likely is stupid. That said, coming from the 'I haven't a clue' perspective it is terrifying. Right back to ashp. I must get that paperwork thingy off the architect that gives the heat loss calcs you all keep mentioning. Also at work and nothing much is happening so intensive building/ you tube going on with me going ah!!!!

When we had the ASHP on floor drying mode for the screed the temp got up to 32°C. You wouldn’t want to run it like that obviously but you can easily get the house warm. Once warm it stays warm. The biggest advantage is consistent temps throughout the house. The house we rent is a leaky old farmhouse with no insulation. It’s freezing generally but the temps vary massively from room to room. 

[Thorfun]

18 hours ago, SteamyTea said:

@CalvinHobbes

 

What room temperature are you trying to reach?  This is what determines your heat source.

You can if you want do a combination heating systems i.e. wet ASHP and an A2AHP.

 

I was at my Mother's Care home yesterday, noticed that there is a number of ASHPs on the building.  Had a little route about and it seems the place is heated with them, why the radiators do not seem hot, but they are near enough on all the time.

We went this approach. ASHP for ground floor UFH and A2A for first floor and cooling throughout. Despite having external shading I was worried about overheating and so fitted AC which can be used for supplemental heating if required. Could give @CalvinHobbes the “instant heat” you’re after while also being useful in the years to come. 

Edited April 1 by Thorfun