ASHP possible in my small toilet/utility room? + Convincing installer to ditch split system and fit monoblock instead

[Dan_the_man]

I had wanted to fit a Gas boiler in a new house extension but now I want to fit an ASHP and I have briefly spoken to a MCS Certified ASHP installer about fitting an ASHP with UFH on the entire ground floor & DHW. The installer suggested installing a Hitachi Yutaki-S at the bottom of my garden which is roughly 18 metres away from my toilet/utility room where the pipework/hot water tank will be fitted. The installers chosen ASHP is of the split variety and I want to avoid a split system due to my bedroom being directly above the toilet/utility which might disturb my sleep with the noise generated from the internal compressor from the split ASHP.

 

I would rather install a Hitachi Yutaki-M which is a monoblock version as it would take up less space internally in my house and would move the compressor noise outside away from my bedroom. I have read a few threads mentioning that monoblock systems can be installed over 20 metres from the hot water tank but the outside pipe work must be well insulated and buried. I have also emailed Hitachi directly with my below plans to see if they recommend fitting a monoblock ASHP 20 metres distance from the in house pipework/hot water tank.

 

Here are my existing plans which have a gas boiler installation specified. I have shown where the ASHP and internal water tank will be located and the distance between them.

 

 

 

 

I guess I have four main questions,

 

1) Is it possible to fit a monoblock in my scenario

2) If it is possible to fit monoblock system what info would it take to convince my installer to fit a monoblock system or will they not budge on the idea of a split system

3) Worse case scenario I have to go for the split system will the internals even fit in my small utility room. Please see below drawings to get an idea of the size and where the tank/pipe work would have to be placed. In these drawings I have a gas boiler installed beside the toilet which will no longer be the case. I have a washing machine plus tumble dryer but if I really needed space I could remove the tumble dryer and just use a retractable clothes horse to dry my clothes.

4) If I get split system is my space large enough to install sound insulation?

 

Many thanks

 

 

 

 

[Conor]

1) Yes it is - confirm the pipe diameter requirements with manufacturer

2) Find another installer.

3) There's no reason at all you'd NEED to get a split system.

[Dan_the_man]

28 minutes ago, Conor said:

1) Yes it is - confirm the pipe diameter requirements with manufacturer

2) Find another installer.

3) There's no reason at all you'd NEED to get a split system.

 

Thank you Conor,

 

If I get the monoblock system will the hot water tank, buffer tank, pipe work, and underfloor heating manifolds all fit inside my utility room ok? please see the drawings. The drawings show a gas boiler which does fit ok. The utility room is 1500 wide.

[Conor]

I doubt it - you'd need equiv of a full height 800mm unit for a slimline 150l tank, and another 600x800mm cabinet for a 60l buffer tank. and a bit of room between for the pipework. I'm using a 2m wide wall in my utility - floor to ceiling.

 

Do you have space under your stairs?

 

Hate to say it but a gas combi would be a neater option.

[Dan_the_man]

4 minutes ago, Conor said:

I doubt it - you'd need equiv of a full height 800mm unit for a slimline 150l tank, and another 600x800mm cabinet for a 60l buffer tank. and a bit of room between for the pipework. I'm using a 2m wide wall in my utility - floor to ceiling.

 

Do you have space under your stairs?

 

Hate to say it but a gas combi would be a neater option.

 

Yes I have space under my stairs.

 

This is a house for life so I will be living in it for the next 40 years at least. In your opinion will I have to rip out any Gas boiler I would be fitting within that 40 year time frame? My theory is yes I will have to rip it out and replace it with ASHP within my life time. So my thought was to get it over with now rather than worry about it down the line.

[joth]

What is the layout upstairs? Have you considered options to wall-mount a monoblock higher up? This would reduce the pipe distance needed but obviously might have some aesthetic and access drawbacks.

 

[Dan_the_man]

 

18 minutes ago, joth said:

What is the layout upstairs? Have you considered options to wall-mount a monoblock higher up? This would reduce the pipe distance needed but obviously might have some aesthetic and access drawbacks.

 

 

There is a flat roof upstairs which the ASHP could be mounted on. I saw one other post on here where someone did that. The ASHP fitter refuses to fit it on the flat roof though.

 

 

 

 

 

 

Edited November 5, 2021 by Dan_the_man

[joth]

So on top of the first floor flat roof? Does sounds ideal in many ways, but can see probably needs special access/handling HSE procedures to install, and you'd want some sort of flat rood hatch and "loft ladder" to get up there for service from time to time.

Have you had quotes from other installers? 

 

[Dan_the_man]

10 minutes ago, joth said:

So on top of the first floor flat roof? Does sounds ideal in many ways, but can see probably needs special access/handling HSE procedures to install, and you'd want some sort of flat rood hatch and "loft ladder" to get up there for service from time to time.

Have you had quotes from other installers? 

 

 

I am in Northern Ireland and there are only two MCS registered installers. The other one I have not contacted as they did not get good reviews.

 

Thinking about access to the ASHP could I not allow access through the landing window. (I have put an arrow to show which window). So you would open the landing window then walk on the glass light well window to a ladder fixed to the bathroom wall?

 

[TW9]

You could use a Sunamp heat battery instead of a hot water cylinder. It isn't a cheap option but it's a lot smaller and might fit in the corner.

[Dan_the_man]

12 minutes ago, TW9 said:

You could use a Sunamp heat battery instead of a hot water cylinder. It isn't a cheap option but it's a lot smaller and might fit in the corner.

 

Would that not be expensive to run, i.e. I want to run a bath surely its just like boiling a massive kettle? £10 to have a bath?

[SteamyTea]

Just skimmed though the thread.

Can you build a shed outside to hold some of the gubbins.

A well insulated shed that is.

[Dan_the_man]

22 minutes ago, SteamyTea said:

Just skimmed though the thread.

Can you build a shed outside to hold some of the gubbins.

A well insulated shed that is.

 

Do you mean a shed to house the hot water tank , under floor manifolds etc? Would that be even practical. The only place I can fit a shed would be at the very bottom of the garden as marked on the first image.

[SteamyTea]

36 minutes ago, Dan_the_man said:

Do you mean a shed to house the hot water tank , under floor manifolds etc

Yes, or just the I door pump if a split system. That would not be very large and any noise would be outside.

[TW9]

1 hour ago, Dan_the_man said:

 

Would that not be expensive to run, i.e. I want to run a bath surely its just like boiling a massive kettle? £10 to have a bath?

The Sunamp can be charged from the heat pump so it's no more expensive to run than a hot water tank... actually a bit less as there is less heat loss and no need to run legionnaires cycles.

[Dan_the_man]

12 minutes ago, TW9 said:

The Sunamp can be charged from the heat pump so it's no more expensive to run than a hot water tank... actually a bit less as there is less heat loss and no need to run legionnaires cycles.

 

That solution sounds very appealing then. Thanks

[SteamyTea]

32 minutes ago, TW9 said:

The Sunamp can be charged from the heat pump so it's no more expensive to run than a hot water tank... actually a bit less as there is less heat loss and no need to run legionnaires cycles.

The SA may need a higher input temperature, so it can kill the CoP.

[Dan_the_man]

19 minutes ago, SteamyTea said:

The SA may need a higher input temperature, so it can kill the CoP.

 

 

Will day to day running costs with the Hitachi Yutaki-M ASHP and Sunamp for hot water will be roughly the same as the Combi Gas boiler?

Edited November 5, 2021 by Dan_the_man

[SteamyTea]

Just now, Dan_the_man said:

 

 

Will day to day running costs with the Hitachi Yutaki-M and Sunamp for hot water will be roughly the same as the Combi Gas boiler?

I cannot answer that as I know nothing at all about that ASHP, or the combi you currently have.

What I can say is that some days it will be cheaper.

[TW9]

Our Sunamp needs 45 degree water so shouldn't cause a problem with CoP.

[Dan_the_man]

Does anyone have any answers to the suggestion of putting the ASHP on the flat roof and my idea of having the ladder access through the landing window.

[SteamyTea]

12 minutes ago, Dan_the_man said:

Does anyone have any answers to the suggestion of putting the ASHP on the flat roof and my idea of having the ladder access through the landing window.

Someone on here put their ASHP on a flat roof.

Bit if searching should find it.

 

Was @Marvin

 

 

Edited November 5, 2021 by SteamyTea

[Dan_the_man]

Yes I had saw that. I guess my concern is if it ever breaks and needs replaced do you have to hire a crane.

[Marvin]

1 hour ago, Dan_the_man said:

Yes I had saw that. I guess my concern is if it ever breaks and needs replaced do you have to hire a crane.

Good question.

 

Well if it's a small problem access is required. If it's a big problem and it has to come down then it would either have to be dismantled or down the same way it went up which was via a scaffold, even though its only on a ground floor roof.

Edited November 5, 2021 by Marvin
Clarification