Are ASHP the way to go?

Astria

I've gone for a air-2-air heat pump, the disadvantages is that you need multiple units, but the advantage is cost and the ability to instantly feel warm in the room you are in, plus it can do cooling in summer too. Power consumption can be as low as 500W, so it might even be possible to get it to run from solar panels. Obviously it can react faster if you supply more power though, and it can easily use up a few KW at max settings, but I'm thinking in summer there will be plenty of power, and so in theory should be able to get at least some cooling for free (already getting some heating for free)

Mstty

Astria said:

I've gone for a air-2-air heat pump, the disadvantages is that you need multiple units, but the advantage is cost and the ability to instantly feel warm in the room you are in, plus it can do cooling in summer too. Power consumption can be as low as 500W, so it might even be possible to get it to run from solar panels. Obviously it can react faster if you supply more power though, and it can easily use up a few KW at max settings, but I'm thinking in summer there will be plenty of power, and so in theory should be able to get at least some cooling for free (already getting some heating for free)

What make and model did you go for and living up to expectations?

markin

matt_drummer said:

markin said:

matt_drummer said:

Some people might say that it is a small price to pay to stop burning fossil fuels in their home.

I would say, if you can afford it, go for it.

Or better spent on more insulation, Triple glazing, More solar, Or an EV.

Or all of that and an ASHP?

Although none of that will end their use of gas if that is their aim.

If they double the insulation and get a heat recovery ventilation system (MVHR) then it could be neither Gas or ASHP as it would be at almost passive house levels.

But everyone has a budget to keep to.

Scot_39

Spoonie_Turtle said:

Mstty said:

I would suggest going for a named brand that has been in the ASHP market for a long time.

And make sure to go for a model that doesn't have an expensive standby consumption.

Read one thread of "vampire" costs of ASHP compressor heater pulling 200W continuously - thats nearly 5kWh daily - and manufacturer saying standard for model - others quoted more than double.

That 5kWh more than I use - including emmersion heater - some days in summer.

But then others say 2kWh daily or close to none.

Do they now actually quote these figures on spec sheets.  Or what to look for (compressor type ?) etc to avoid ?

Spoonie_Turtle

Scot_39 said:

Spoonie_Turtle said:

Mstty said:

I would suggest going for a named brand that has been in the ASHP market for a long time.

And make sure to go for a model that doesn't have an expensive standby consumption.

Read one thread of "vampire" costs of ASHP compressor heater pulling 200W continuously - thats nearly 5kWh daily - and manufacturer saying standard for model - others quoted more than double.

That 5kWh more than I use - including emmersion heater - some days in summer.

But then others say 2kWh daily or close to none.

Do they now actually quote these figures on spec sheets.  Or what to look for (compressor type ?) etc to avoid ?

That's similar to ours - 35-50kWh in a month spent on "heating" (zero output, literally just standby power) making our minimal hot water usage in summer turn out to be expensive!  

Err … I can't remember exactly what the conclusion was across numerous threads I read to try to get to the bottom of it.  I'll have a dig through my screenshots and see if I can find it.

There was something about scroll compressors, I think?  Ours isn't one, so it might be that those won't have it.

Mstty

Spoonie_Turtle said:

Mstty said:

I would suggest going for a named brand that has been in the ASHP market for a long time.

And make sure to go for a model that doesn't have an expensive standby consumption.

Probably a good time to start a list of "high resting standby consumption makes and models"

I can say our Mitsubishi Ecodan 8.5kwh was on all summer heating the water 4 times a week and does not have a vampire load...thankfully.

As an aside apparently our model can do cooling as well with a couple of switches activated, anyone tried this in the summer months with under floor wet system on their ASHP and did it make any difference.

Jinglish

If your bungalow doesn’t have proper floor insulation or at least a decent concrete slab then I think you might be spending a fair chunk of money heating the soil below so you might be better off using radiators. However if it is suitable then I would consider fitting UFH upstairs too as in the summer a decent ASHP can be run in reverse to provide cooling, which I believe only works if the whole house is UFH.

My system was a Vaillant aroTherm Plus & Unitower it was brilliant. Highly recommend.

markin

Jinglish said:

If your bungalow doesn’t have proper floor insulation or at least a decent concrete slab then I think you might be spending a fair chunk of money heating the soil below so you might be better off using radiators. However if it is suitable then I would consider fitting UFH upstairs too as in the summer a decent ASHP can be run in reverse to provide cooling, which I believe only works if the whole house is UFH.

My system was a Vaillant aroTherm Plus & Unitower it was brilliant. Highly recommend.

Its pretty much understood to be standard practice to pull the floor up, And in an older home its a good time to redo all the pluming, wiring, and to do the correct vapour barrier.
In a more modern home its just a 40mm screed on top, Or a system clipped to the under side of the floor boards.

gazb_2

Jinglish said:

If your bungalow doesn’t have proper floor insulation or at least a decent concrete slab then I think you might be spending a fair chunk of money heating the soil below so you might be better off using radiators. However if it is suitable then I would consider fitting UFH upstairs too as in the summer a decent ASHP can be run in reverse to provide cooling, which I believe only works if the whole house is UFH.

My system was a Vaillant aroTherm Plus & Unitower it was brilliant. Highly recommend.

Sorry, I should have said. All the floors are being knocked up and then hardcore, kingspan and screed on top

Spoonie_Turtle

Mstty said:

Spoonie_Turtle said:

Mstty said:

I would suggest going for a named brand that has been in the ASHP market for a long time.

And make sure to go for a model that doesn't have an expensive standby consumption.

Probably a good time to start a list of "high resting standby consumption makes and models"

I can say our Mitsubishi Ecodan 8.5kwh was on all summer heating the water 4 times a week and does not have a vampire load...thankfully.

Ours is also Ecodan, PUHZ-W85VAA (does that mean it's 8.5kW?).

A screenshot of one site I found says the PUHZ- is the R410 model, whereas PUZ- is the R32 model.  Unfortunately my tablet didn't do its clever thing of linking to the website - I think I took a screenshot of that because the R32 models didn't have a vampire load whereas ours (an R410) does, but I can't be 100% certain, the context is slightly unclear.

I do not know what the different models mean, either, but the terms are there for anyone wanting to investigate.