Heat Pumps - post here.

Latro · 24-08-2018 1:49pm

John.G wrote: »

Its not clear to me at least but have you upgraded your house insulation (just) before you installed the HP and what form of heating are you converting from?.
It will be very interesting to see how fast the house will take to heat up after being off from midnight to 0700 each night bearing in mind that you will now have ~ 30 deg rads with ~ 50% output of the 50 deg rating.
The best of luck with your installation.

The rads water temperatures will be on a curve from 40 to 50 degrees between 15 to -5 degrees outside. As I'll be gaining experience with the system I'll adjust it if they are too low or too high.

Before HP installation I was running something like pellet boiler with large hopper but instead of pellet it used small pea coal. It was cheap enough system to run (about 600-700/year) but the necessity of cleaning it every 10-12 days from sludge made my garage completely unusable because of dust everywhere.
I wanted perfect clean garage so I decided to get rid of it and do a full renovation. I'd probably keep the old system if I had totally separate room dedicated for the purpose but that option would be quite expensive.
Also I don't need to store large pile of coal bags in my shed anymore.
The water temperature I ran on that was too 45-50 degrees but it was circulating 24/7 with TRVs cutting off rads when too warm.

Before I moved in the system was designed to take oil boiler and I didn't modify it at all just connected the other boiler with 3 way valve.
Now the heat pump is connected directly to it as if it was oil.

I upgraded insulation in the attic in 2013 when we moved in. And now with HP install I didn't do any modifications at all.

Carrickbeg · 24-08-2018 4:03pm

Latro wrote: »

I retrofitted 9kW A2W in to my house last month.

I will post here how it goes once the heating season starts.
So far we use it to heat DHW 280L tank.
Water temp 45 degrees, at the moment cost according to the manufacturer app is 12-15 cents per day. 2 adults+1 child.

The target is to have constant 20-21 degrees throughout the day. The heating window initially is going to be from 7am to midnight with downtime for the night to avoid low external temperatures.

Some stats:
2 storey detached house with attached garage(heated), in total around 200sqm heated surface. Finished in 2013 to pre 2008 regs. Timber frame.
Ground floor: open plan, office, utility, toilet, garage.
First floor: 3 bedrooms, 2 en suite, bathroom, TV/play room, hot press, small walk-in wardrobe.

Insulation:
-walls 6 inch fibreglass
-slab: no idea here since I bought the house at near builders finish state and never had opportunity to see whats in it.
-attic: initially there was 10(4+6) inches of fiberglass, upgraded with another 2 layers of 6 inch of the same in criss-cross pattern. In total 22 inches. Heh I know, a lot, but it is relatively cheap material and easy to DIY.

Windows: known brand PVC, double glazed.
Ventilation: traditional holes in the walls, I'm contemplating upgrading to heat recovery, maybe next year, depends on this season heating bills.

Steel, double Radiators: 8 fairly large downstairs and 6 of the same upstairs plus 4 towel rails in total.

Fingers crossed it is enough. If not I will add few more as this option would be far cheaper than going underfloor at this stage. Also easy DIY-able with timber frame.

3 zones for heating: ground floor, 1st floor and DHW tank. No zone thermostats at all, TRVs on all rads.

Heat pump: 9kW, monoblock, inverter, single phase with cooling option and desktop PC or android phone loging/monitoring/operating bells and whistles.
One of the latest model of big, known brand.

12 - 15 cents to heat 280L of hot water? That's 1kwh on my electricity charges...

John.G · 24-08-2018 5:09pm

Carrickbeg wrote: »

12 - 15 cents to heat 280L of hot water? That's 1kwh on my electricity charges...

Its possibly referring to the energy required to supply water at 45C for the three occupants from a fully heated 280 Litre tank?......if one just assumes a average hot water demand of 50 Ltrs/person/day then energy (water input) required is
150*(45-15)/860, 5.23 Kwh. HP input ~ 1 Kwh, COP (5.23/1), 5.23, quite possible one would think with the present high ambient temperatures and no need for HP defrost?.

Latro · 24-08-2018 6:06pm

John.G wrote: »

Its possibly referring to the energy required to supply water at 45C for the three occupants from a fully heated 280 Litre tank?......if one just assumes a average hot water demand of 50 Ltrs/person/day then energy (water input) required is
150*(45-15)/860, 5.23 Kwh. HP input ~ 1 Kwh, COP (5.23/1), 5.23, quite possible one would think with the present high ambient temperatures and no need for HP defrost?.

That's exactly what I meant. Also water in the tank probably never drops to 15 degrees at this time of the year. And there is some left over heat in it from previous day.
Seems there is 0 reasons to go solar once you have HP with hot water on demand any time of the year.
But anyway, it is warm outside so I don't get too exited yet.
The real test will be Dec,Jan and Feb.

Not sure how to post a picture here.

https://imgur.com/a/fDmScez

John.G · 25-08-2018 8:56am

Latro wrote: »

That's exactly what I meant. Also water in the tank probably never drops to 15 degrees at this time of the year. And there is some left over heat in it from previous day.
Seems there is 0 reasons to go solar once you have HP with hot water on demand any time of the year.
But anyway, it is warm outside so I don't get too exited yet.
The real test will be Dec,Jan and Feb.

Not sure how to post a picture here.

https://imgur.com/a/fDmScez

As you say "The real test will be Dec,Jan and Feb." as @ A0 W45 the output may be < 6.0 Kw and @ A-3 W45 it may be as low as 5.0 Kw. Was there any particular reason why you went for a 9 Kw unit as against say a 12 KW (or higher) especially when you selected VSD.

Latro · 25-08-2018 11:30am

According to my own calculations based on fuel used with old system my house needs between 60 to 100kWh per day to compensate for the heat loss.

100kWh/5kW=20h and that is when temperature dips to -5(very rare).
And at this cold the compensating curve is set do raise the temperature to 50 degrees.

If it gets even colder for that odd week once per few years I don't mind boosting it with built-in immersion, it should not affect heating cost long term too much.
Also there is the stove in the living room to give additional kick but I'm against that form of heating unless you have free fuel. I use it maybe 2 times a year and not even for heating purposes.
Anyway, that's all theory, I'll keep you posted with real life numbers as winter progresses.

stoves1 · 27-08-2018 9:53pm

I am presently considering a works on my house a standard 3bed semi detached, the proposal is to get the house insulated incl external walls, windows doors etc underfloor heating with aluminium rads upstairs which at the end i have been guaranteed an A3 rating, i am happy to go ahead but wondering will a mitsubshi ecodan 5kw heat pump along with a 150 litre pre plumbed hot water cyclinder be suffice to offer us the hot water we need for showers and the heat we will require in winter, i would appreciate your comments

Latro · 27-08-2018 10:32pm

What is heated sqm area of the house?
A3 house requires between 50 and 75kWh/1sqm/year.
I'm no expert at BER but I'd think 70-80% of that is spent on heating.
You can work your numbers from there.
Don't be too optimistic with HP efficiency and there should be no problem with figuring it out. I'd assume 2.6-2.7 average winter COP.

Water John · 27-08-2018 11:21pm

Be very sure the correct insulation is going under the floor if you are installing UFH.

John.G · 28-08-2018 7:54am

stoves1 wrote: »

I am presently considering a works on my house a standard 3bed semi detached, the proposal is to get the house insulated incl external walls, windows doors etc underfloor heating with aluminium rads upstairs which at the end i have been guaranteed an A3 rating, i am happy to go ahead but wondering will a mitsubshi ecodan 5kw heat pump along with a 150 litre pre plumbed hot water cyclinder be suffice to offer us the hot water we need for showers and the heat we will require in winter, i would appreciate your comments

I know you hope to get a A3 rating but have you any idea of your heating requirements now based on Gas/oil usage.? A 5 KW unit seems very optimistic bearing in mind that its output will be as low as 3.0 KW on cold winter days, and also regular defrosting must be kept in mind. Has a heating "expert" sized the HP for you?, IMO the electric auxiliary heating element could be in use quite a lot if you go for this unit. If it was my house I would be far happier to install at least the 8.5 KW unit and possibly bigger.

John.G · 01-09-2018 8:46am

John.G wrote: »

Do any of the ASHP manufacturers display the time on defrost cycle(s) and the compressor energy required since defrosting has such a huge effect on the COP/SPF of the installation or has any user any data/info on this?.

Some interesting info here including info on above even though its for one period....Nov 2016.
https://passivehouseplus.ie/magazine/feature/the-ph-guide-to-air-source-heat-pumps

Easter Sunday · 01-09-2018 11:31am

Hi John,
Not sure but this is a big thing for me too.

After doing a lot of research and speaking to multiple installers( most of whom could not answer my defrost cycle question to my satisfaction), we think we will go with a CTC as it only defrosts when needed, it has much wider (anti corrision) coils at the back to reduce frosting and it’s pv panel ready.

Apparently others ice up easily due to tight coils, they rust and they defrost every few minutes when the temperature drops below a certain degree whether it’s needed or note. Also most others are not pv panel ready, despite what installers tell you.

Please note I am no expert, just building my new house and my advice is based on what I believe to be true and what makes sense to me.

John.G wrote: »

Some interesting info here including info on above even though its for one period....Nov 2016.
https://passivehouseplus.ie/magazine/feature/the-ph-guide-to-air-source-heat-pumps

John.G · 02-09-2018 9:25am

I think it has been pointed out that a lot of HP manufacturers were originally in the AC business and didn't pay too much attention to the heat exchanger fin design/spacing etc when using the AC condenser as the now HP evaporator whereas CTC and some others designed the HP properly but I suppose cost is king.
Could you please tell me what do you mean by this "Also most others are not pv panel ready, despite what installers tell you."

Easter Sunday · 02-09-2018 1:30pm

I was told by several different installers ( who each installed only 1 brand) that their systems were compatible with pv panels as long as they were wired for pv.

I wasn’t quite convinced as a sales man for one of these brands at the Ideal Homes Exhibition told me that they weren’t currently ready but that a new model next year probably would be.

I then spoke to an installer who fits several brands ( including these aforementioned brands ) and he told me that neither of the brands I had researched is pv panel ready ( something to do with an immersion I think). He had nothing to lose by telling me that as he installs them anyway...he wasn’t pushing any particular brand on me -just explaining the difference.

So just be sure you’re happy with the capability of your brand / model.

quote="John.G;107968753"]I think it has been pointed out that a lot of HP manufacturers were originally in the AC business and didn't pay too much attention to the heat exchanger fin design/spacing etc when using the AC condenser as the now HP evaporator whereas CTC and some others designed the HP properly but I suppose cost is king.
Could you please tell me what do you mean by this "Also most others are not pv panel ready, despite what installers tell you."[/quote]

John.G · 03-09-2018 4:20pm

Easter Sunday wrote: »

I was told by several different installers ( who each installed only 1 brand) that their systems were compatible with pv panels as long as they were wired for pv.

I wasn’t quite convinced as a sales man for one of these brands at the Ideal Homes Exhibition told me that they weren’t currently ready but that a new model next year probably would be.

I then spoke to an installer who fits several brands ( including these aforementioned brands ) and he told me that neither of the brands I had researched is pv panel ready ( something to do with an immersion I think). He had nothing to lose by telling me that as he installs them anyway...he wasn’t pushing any particular brand on me -just explaining the difference.

So just be sure you’re happy with the capability of your brand / model.

quote="John.G;107968753"]I think it has been pointed out that a lot of HP manufacturers were originally in the AC business and didn't pay too much attention to the heat exchanger fin design/spacing etc when using the AC condenser as the now HP evaporator whereas CTC and some others designed the HP properly but I suppose cost is king.
Could you please tell me what do you mean by this "Also most others are not pv panel ready, despite what installers tell you."

[/QUOTE]

The normal Solar PV can have a diverter installed that will send any surplus power to a electric immersion in a hot water cylinder so I assume that you are saying that this power could be diverted to the HP auxiliary heating element instead and therefore the HP should be able to recognize this and accept the switched surplus and that this is what is meant by "PV Panel ready"?.

MENACE2010 · 05-09-2018 4:06pm

Hi
check the type of hot-water cylinder you are going to use , some of them will have a heating element in it , connect the divert to the heating element and it will heat the water in the tank. .the heatpump should detect the hot water temperature and decide to kick in or not. (Regardless my HP will cycle the hot water to avoid Legionnaires disease to 70 degrees ..so there will be some extra cost )

search for PV batteries instead, there is a supplier in Ireland that sells modular battery storage that can work with the HP and the house .. so you store the excess in battery storage and use it at night for lighting and telly(s) and hot water generation for the HP.

the challenge is though the numbers don't add up .. I have been through this with a PV installer and the payback time is Years .. and then some ..I dont have that spare cash to burn on a lofty and green initiative ..

WLad · 05-09-2018 6:20pm

Has anybody set up any type of smart system with these heat pumps? Ours is a dimplex air to water and wondering how easy it is to change over to something like alexa controlling sonoff switches or something similar. Thanks.

MENACE2010 · 06-09-2018 11:14am

Hi
I tried , eg researched our HP has smartlink.. but that only governs the heating not the hotwater. .. there a "port" you can dabble with but my other half is not that thrilled with "experiments" .. we also have a webinterface , but I'm not sure how "hackable" that is .. i would love to have more "AI " on my heatpump , eg it pre-empts good weather.. more solar gain = less heatpump heat.

Google for the service manual for your heatpump and you will discover where is what, and what you can steer .

WLad · 06-09-2018 11:22am

MENACE2010 wrote: »

Hi
I tried , eg researched our HP has smartlink.. but that only governs the heating not the hotwater. .. there a "port" you can dabble with but my other half is not that thrilled with "experiments" .. we also have a webinterface , but I'm not sure how "hackable" that is .. i would love to have more "AI " on my heatpump , eg it pre-empts good weather.. more solar gain = less heatpump heat.

Google for the service manual for your heatpump and you will discover where is what, and what you can steer .

Exact same as me, my track record with experimenting and then breaking things isn't great so she doesn't trust me

The hot water wouldn't bother me, I am really just looking to make it so that I can get Alexa or whatever to turn on the heating in specific zones before I get home. I will research anyway, thanks for your input!

KCross · 06-09-2018 11:36am

MENACE2010 wrote: »

Hi
i would love to have more "AI " on my heatpump , eg it pre-empts good weather.. more solar gain = less heatpump heat.

Does your heat pump not do weather compensating?
I thought that was standard enough... i.e. a temp gauge outside that the HP monitors and adjusts its run time accordingly.

WLad wrote: »

I am really just looking to make it so that I can get Alexa or whatever to turn on the heating in specific zones before I get home. I will research anyway, thanks for your input!

HP's dont really work that way. If you are sending it a signal at 5pm to have a room warm for you by 6pm you are going to be disappointed. HP's need hours to build up the UFH temp and then release it.

You are thinking of the old style oil burner and rad type system where you turn it on and it fires out 60C heat within minutes. HP's deliver <30C to the UFH and then it takes time for that to "seep" through to the house.

You shouldnt really be turning anything on or off on the heat pump. Set it to the temp that is comfortable for you and your house and then let the HP manage that itself.

WLad · 06-09-2018 11:39am

KCross wrote: »

HP's dont really work that way. If you are sending it a signal at 5pm to have a room warm for you by 6pm you are going to be disappointed. HP's need hours to build up the UFH temp and then release it.

You are thinking of the old style oil burner and rad type system where you turn it on and it fires out 60C heat within minutes. HP's deliver <30C to the UFH and then it takes time for that to "seep" through to the house.

You shouldnt really be turning anything on or off on the heat pump. Set it to the temp that is comfortable for you and your house and then let the HP manage that itself.

Ah. Ours is on oversized rads instead but the principal is similar if just less efficient I suppose. Ok well at least I know anyway. Thanks.

John.G · 17-09-2018 9:10pm

Carrickbeg wrote: »

12 - 15 cents to heat 280L of hot water? That's 1kwh on my electricity charges...

Friend of mine has just returned from Co Kerry where he was visiting people in a new build with what he thinks is the above system.
It is put together by a firm based in Little Island in Cork and apparently has a fairly conventional A2W outdoor/indoor system supplying low temperature hot water to the UFH which is installed both upstairs and downstairs.
The domestic hot water is supplied from a unit with its own compressor and a 300 litre hot water cylinder and utilizes exhaust air from the kitchen area which is then expelled to the outside.

BFMadden · 17-10-2018 9:26pm

Guys,

Has anyone any experience of an Ovum heat pump and DHW system? They're an Austrian brand that is supplied and installed by Climate Control in Galway. Looks good but there's very little info on it.

ovum.at

Open link with Chrome to translate.

Thanks

Shefwedfan · 30-10-2018 10:25pm

Just wondering are many people using A2W heat pump with standard radiators? it seems most companies now have option

H.E. Pennypacker · 30-10-2018 10:56pm

Shefwedfan wrote: »

Just wondering are many people using A2W heat pump with standard radiators? it seems most companies now have option

I've had a few quotes for A2W retrofit. Most companies who have experience with this are happy to talk about a potential multi-step approach where the customer can try the HP with existing radiators. One suggested running the existing OFCH at 40C supply to see how it goes. Its not ideal if you'd like to maximise the lifespan of your existing boiler but as a stepping stone its a very useful insight.

The biggest issue that I've found is that the companies most willing to deal aren't yet SEAI approved for grant purposes. It requires FETAC Level 6 plumbers and a lot of companies are aircon, not plumbing companies. That said, the SEAI requirements are very relevant for a retrofit scenario in terms of the fabric first approach and in my experience, they tend to maintain standards with contractors. You would need to have confidence in the heat loss attributes of your house and without a heat loss indicator of max 2.2 for retrofit you can't say for sure that it'll pay.

zoom_cool · 31-10-2018 9:35am

Does anybody have Firebird offering of AWH pump sister is building new house and got a quotation and they where very competitive. The system is called Enviroair Hybrid Heatpump which has a oil burner as a backup.

John.G · 31-10-2018 10:30am

zoom_cool wrote: »

Does anybody have Firebird offering of AWH pump sister is building new house and got a quotation and they where very competitive. The system is called Enviroair Hybrid Heatpump which has a oil burner as a backup.

Grant do a similar Hybrid which can be used for comparison purposes if not all ready done so.

KCross · 31-10-2018 11:29am

zoom_cool wrote: »

Does anybody have Firebird offering of AWH pump sister is building new house and got a quotation and they where very competitive. The system is called Enviroair Hybrid Heatpump which has a oil burner as a backup.

I dont have experience with them but they seem like something you would install as a retrofit rather than something for a new house where you have high levels of insulation, air-tightness and heat recovery ventilation.

i.e. Why would you install a hybrid system that will be more complex and likely to be less reliable in the long term and have to continue to pay for oil.

Unless it was significantly cheaper it would make more sense to me, in a new build partiularly, to just install a correctly sized heat pump and leave it at that.

zoom_cool · 31-10-2018 1:28pm

There is some smart logic so when it is more efficient to run oil boiler it will. The price was competitive same and cheaper to some standalone heat pump quotations.

KCross · 31-10-2018 1:47pm

zoom_cool wrote: »

There is some smart logic so when it is more efficient to run oil boiler it will. The price was competitive same and cheaper to some standalone heat pump quotations.

But it will be a more complex system and you have to have an oil tank and oil burner and it will need more servicing and you have to order oil etc etc.... I just dont see why you would do that over having a single heat pump system in a new build house. I just dont see the advantages (smart controls or not) outweighing the disadvantages unless the price differential was significant

Note, you can tweak heat pump settings to take advantage of night rate electricity as well. You cant run it entirely at night but you can limit it and in a new build, with low heat demand, I dont think oil should be considered at all, imo.

For a retrofit it might make sense.

For a new build you should be looking to get as much of your consumption onto electricity as you can with an eye to SolarPV. Putting in oil in a 2019 house is questionable,again imo.

Heat Pumps - post here.

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