Heat Pumps: anyone have one/thought about it?

PishY said:
I don’t think there is a problem with them, the problem I find is the customers/end users always think the radiators should be boiling to the touch, where the system isn’t designed to go past a 55 degree flow temp as it would be inefficient and the heat-pump wouldn’t beable to get the flow temp to that without additional electric heaters to Boost it, there fore becoming inefficient
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what problems/solutions does the use of popular smart radiator valves with heat pumps introduce ?
if many need a low 5k/dt drop to be efficient(for synthetic refrigerant), is that compatible with having just a few smart radiators on -
do you spec many expensive picv valves and variable pumps to keep it that efficiency range .. or just take that hit.

e: do you use a piece of software to help configure/design domestic systems
 
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The consensus is that you leave them fully open all the time.

When heating with low temperatures and weather compensation, they become less important.

I would t also suggest smart radiator valves are popular either. Popular on a tech forums perhaps, but not in real life.
 
PishY said:
for every 1KW they use of electric the AC outputs nearly 4KW of heat, which is remarkable !
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If you're lucky :p

You probably design systems properly for the fabric/vent heat loss which is soo important.

How do you find the newer Daikin Altherma 3 H HT systems? I'm just starting to consider a Heat Pump with the increased grant, but need to factor in my max heat loss of 13.5kW at -3 DOT.

That level is right at the peak of most commercial units (Vaillant Arotherm 12kW would just cover it actually), but just this morning I've just been looking at the new 14kW Altherma 3 H HT with the all-in-one 230L tank unit.

Rads are either old double panel/finned, or I'm going to put large K2 in if required. Got a suspended timber floor with pine T*G floor that I'm insulating for this winter, then putting wet UFH under (with spreader plates) next year. With the UFH heating installed an around 40degsC mixed temp, it should allow rads and heat pump to work with a Delta 20-25C temp (40-45 flow). Then with the heat pump installed I guess the pump and mixerc could be removed from the UFH manifold and everything run via WC.
 
jonneymendoza said:
You still may need to make some adjustment to your home in order to use a heat pump as it works differently to a combi boiler.

Some may need new bigger radiators. Some may need new pipe work and a bit more insulation. It depends and people need to be prepared for a much higher electricity bill for obvious reasons.

See how complex a heating system is? Of course there will be some customers that would be clueless as it's a lot to take in order to understand how the whole process works
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It's endemic in the UK, though. Most people have no idea how their heating works, which is to their detriment. We all known enough about our cars, for example, to ensure we don't go around achieving 10 MPG. You definitely can't say the same for heating systems. We're talking about fundamentals here as well - people don't realise that boiling hot rads are bad, low dTs are bad, fully open valves are bad, etc.

I'm suggesting we, as a nation, need some education.
 
dirtychinchilla said:
It's endemic in the UK, though. Most people have no idea how their heating works, which is to their detriment. We all known enough about our cars, for example, to ensure we don't go around achieving 10 MPG. You definitely can't say the same for heating systems. We're talking about fundamentals here as well - people don't realise that boiling hot rads are bad, low dTs are bad, fully open valves are bad, etc.

I'm suggesting we, as a nation, need some education.
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We should be educated as part of our gcse curriculum
 
jonneymendoza said:
See how complex a heating system is? Of course there will be some customers that would be clueless as it's a lot to take in order to understand how the whole process works
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I dunno man, I think we just need Apple or someone to come along and remove all this nonsense about being complex. At the end of the day it is just water in pipes with big metal radiators.
 
-Ad- said:
If you're lucky :p

You probably design systems properly for the fabric/vent heat loss which is soo important.

How do you find the newer Daikin Altherma 3 H HT systems? I'm just starting to consider a Heat Pump with the increased grant, but need to factor in my max heat loss of 13.5kW at -3 DOT.

That level is right at the peak of most commercial units (Vaillant Arotherm 12kW would just cover it actually), but just this morning I've just been looking at the new 14kW Altherma 3 H HT with the all-in-one 230L tank unit.

Rads are either old double panel/finned, or I'm going to put large K2 in if required. Got a suspended timber floor with pine T*G floor that I'm insulating for this winter, then putting wet UFH under (with spreader plates) next year. With the UFH heating installed an around 40degsC mixed temp, it should allow rads and heat pump to work with a Delta 20-25C temp (40-45 flow). Then with the heat pump installed I guess the pump and mixerc could be removed from the UFH manifold and everything run via WC.
Click to expand...

The Daikin altherma 3 HT are good, I’d defiantly put a buffer tank on the system though, this allows the heatpump to store the heated water before it’s distributed around the hot water tank and hydro box for the central heating, I find that this way the heatpump isn’t working flat out.

I did this last week, a customer of myne had a viessman Vitocal heatpump installed by another installer, it worked but was constantly running to try to achieve a 23 degree temperature in the house (new build) the condenser was 30M away from the indoor unit so we moved this to a sheltered area from major wind, and shortened the pipe run to around 15M and added a Vitocel 100E Buffer tank, reconfigured the pipework and recommissioned and the system achieved the room temperature in around 2 hours which was a major result for the customer.

So I’d defiantly recommend a buffer tank if your planning on going down that route
 
jpaul said:
what problems/solutions does the use of popular smart radiator valves with heat pumps introduce ?
if many need a low 5k/dt drop to be efficient(for synthetic refrigerant), is that compatible with having just a few smart radiators on -
do you spec many expensive picv valves and variable pumps to keep it that efficiency range .. or just take that hit.

e: do you use a piece of software to help configure/design domestic systems
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I’ve never fitted smart radiator valves to a heatpump, just the usual TRV’s. I can’t foresee a problem with having smart ones though, nor having an after party smart thermostat to control the heating side of things, the manufacturers controls are usually pretty good and the newer stuff is controlled by your phone through and app

As for PICV valves I can’t foresee a problem with them either, anything to maintain the flow is always a bonus, I’ve not specifically fitted these on Heatpumps yet as there’s been no need (as of yet)

When i design a System for a customer I get the manufacturer to do it, so it takes the indemnity away from me, and it’s on them then, a rule of thumb though is to calculate what radiator sizes you need and double them in size or output
 
PishY said:
The Daikin altherma 3 HT are good, I’d defiantly put a buffer tank on the system though, this allows the heatpump to store the heated water before it’s distributed around the hot water tank and hydro box for the central heating, I find that this way the heatpump isn’t working flat out.

I did this last week, a customer of myne had a viessman Vitocal heatpump installed by another installer, it worked but was constantly running to try to achieve a 23 degree temperature in the house (new build) the condenser was 30M away from the indoor unit so we moved this to a sheltered area from major wind, and shortened the pipe run to around 15M and added a Vitocel 100E Buffer tank, reconfigured the pipework and recommissioned and the system achieved the room temperature in around 2 hours which was a major result for the customer.

So I’d defiantly recommend a buffer tank if your planning on going down that route
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Cheers, thanks for those tips.

If it it can be sited where I want (depending on the MCS noise assessment I've calculated up), we will only have a 3-5m pipe run max to the indoor unit and it will be straight through the wall from the outdoor unit and into our crawl space. So they can be insulated even further.

A buffer tank could work as the main indoor tower could go in the downstairs toilet bathroom sized room), then the buffer tank could be plumbed in in the cupboard opposite where teh current vented cylinder is.

Unfortunately I'd probably have to sort out the 3.6kW PV & battery install first, likely using a 15kWh Fogstar/SEPLOS unit along with Octopus Cosy to make it viable.
 
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-Ad- said:
Cheers, thanks for those tips.

If it it can be sited where I want (depending on the MCS noise assessment I've calculated up), we will only have a 3-5m pipe run max to the indoor unit and it will be straight through the wall from the outdoor unit and into our crawl space. So they can be insulated even further.

A buffer tank could work as the main indoor tower could go in the downstairs toilet bathroom sized room), then the buffer tank could be plumbed in in the cupboard opposite where teh current vented cylinder is.

Unfortunately I'd probably have to sort out the 3.6kW PV & battery install first, likely using a 15kWh Fogstar/SEPLOS unit along with Octopus Cosy to make it viable.
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Ah nice the shorter the pipe run the better, extra lagging never goes a miss either!

Sound like that will work out well, oh and battery will also compliment it nicely!

Anytime, always here for advice

Cheers
 
We didn't really give much consideration to the distance between the heat pump and the hot water cylinder and the UFH manifold, are we losing much in the way of having long runs? I'd estimate that there's a good 15m+ of pipe between the heat pump and the cylinder, then a further 8m from cylinder to manifold!! Guess we're losing a fair amount of heat along the route, will do my best to ensure the insulation is as good as can be.


Heat pump is outside, under the kitchen window - 28mm glow and return pipework comes through the soffit, through the flat part of the vaulted ceiling (completely inaccessible now!), through eaves cupboards in the vaulted mezzanine area, then in to attic space down the length of the house, before going across in to what will be the family bathroom. Then that returns to the manifold in 22mm pipework.
 
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b0rn2sk8 said:
There isn't much difference between a 2004 and 2012 build in reality. 2012 should be better but not by much, a 2004 will have insulated floors and walls, double glazing and while it probably had 100m loft insulation when new, topping it up to 350mm isn't exactly a hardship or expensive.
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Thanks again, I'm actually happy to replace any radiators gradually to save on costs, as quite a number are singles anyway. Is there any calculation I could use to work out what sizes would be required for a heat pump.
 
PermaChanged said:
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Heat pump is outside, under the kitchen window - 28mm glow and return pipework comes through the soffit, through the flat part of the vaulted ceiling (completely inaccessible now!), through eaves cupboards in the vaulted mezzanine area, then in to attic space down the length of the house, before going across in to what will be the family bathroom. Then that returns to the manifold in 22mm pipework.
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do you chart heat output, in addition to earlier chart data, to estimate overall efficiency ; had scanned this on other forum after earlier post - glories of HA
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Not that I can see, not sure if he has additional 3rd party equipment to get those reports as they're not ones I can access as standard in the Melcloud app, Melcloud being Mitsubishi's software for ASHP monitoring/reporting
 
PermaChanged said:
Not that I can see,
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thread I'd linked was coincidentally for ecodan and suggests melcloud can give flowrate to derive heat output.
Re flowrate. If you go to the service icon, you should be able to find ‘running information’ and if you enter 540, it should give you the flow rate in litres/min. I think the data sheet suggests 11 to 24lit/min.
 
PermaChanged said:
Not that I can see, not sure if he has additional 3rd party equipment to get those reports as they're not ones I can access as standard in the Melcloud app, Melcloud being Mitsubishi's software for ASHP monitoring/reporting
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That report looks like it was from https://heatpumpmonitor.org/. Most of these use heat pump monitoring equipment from Open Energy Monitor.

If you click the graph icon next to any of the heat pumps, you see a monthly energy use by day and if you click into a day you get the plot above, with flow & return temps, energy in and energy out.

As someone who has a heat pump, it’s enough to make me feel quite jealous as I’m nowhere near those COP levels. I averaged 3.7 for October.
 
I'm really not expecting a great COP this winter as we're still waiting for our external wall insulation to be applied (the house is at least cavity built!). Need to get our loft insulation up to scratch over the next few weekends too.
 
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