Plant room location advice

[Dunc]

I would appreciate help on locating my plant room:

Any thoughts on whether to swap the w/c in the utlity with the plant room?

 

Entry area, utility and w/c are planned to be single storey flat roof.

Plant room, en-suite, bed 1 are planned to be 1.5 storey.

Working to Scottish regs, so must have the store area available as the "convertible-to-accessible-shower" and connectable to the w/c area.

 

Current layout:

Entry, utility and w/c are all within a "dirty" area of the house - useful for when working in the garden or garage.

Plant room inside 1/5 storey area - easy to route services across the rest of the building.

MVHR and ASHP main supply/return pipes are further from outside wall. Unsure of possilbe routing.

Risk of noise from plant room? - bed 1 is the master bedroom.

Risk of excessive heat from plant room? [aiming for passive-class build]

 

Swapped layout:

w/c more in the "clean" area of the house - more appropriate for visitors, but no window.

Could remove the door between entry and internal vestibule bit and add a standard door in to the kitchen & rest of house, expanding the "dirty" area slightly.

MVHR & AHSP main supply/return straight through the wall seems more efficient? Would it make services to the rest of the house harder e.g. longer run to kitchen for DHW. Is it easy to access the ceiling-floor void in the 1.5 storey part to route everything?

Reduced risk of noise/heat?

 

[JohnMo]

Question do you need a plant room at all. Also lots of doors going on

 

MVHR wall mount in room identified as plant room or even in the utility.  I mounted mine on a stud wall on two sheets of 18mm ply. No noise in adjacent bedrooms.  Rest of the room as storage. So just relabel as store or cupboard.  If you are having UFH put the manifold in the same room as the MVHR takes up no space, could be under the MVHR unit.

 

DHW cylinder in utility next to ASHP. Located 3 way valve there also.

 

I would check the clearances are ok for the current ASHP position also, looks to be stuck in a corner.

 

No heating required in the utility it gets heated by the cylinder.

[Blooda]

Just some thoughts ? 

What is the route from the utility room to outside to hang your washing up?  What is the route from the garden to w/c.  Is the "ent" the main entrance? or is there another.  Do you need the door between utility and "ent"

 

Outside window in W/C is nice, we had one in the last house.  When we built here, we ended up with no room for a window so had a transom window over the door, gives enough light should you forget [not have enough time] to switch the light on.

 

 

[Bozza]

The single biggest mistake we made with our design was to have the plant room with ASHP internal gubbins pumps etc beneath our master bedroom.  It is very noisy.not the ASHP, just the internal pumps when it is on.  No issue in the summer but a nightmare in the winter.

 

your design has that stuff basically in your bedroom.   which will be even worse.

 

***Strongly*** suggest you move it over towards or even inside the garage.  Also consider what is above it.   put acoustic insulation in the plant cupboard including ceiling.

 

Learn from my mistake.

 

 

 

 

[Dunc]

Some very helpful thoughts here, thank you.

 

Takeaway thus far:

DHW cylinder will kick out a lot of heat (despite being insulated. Can you box them in with additional insulation?) Probably better not right next to the bedroom.

ASHP/UFH pump can be noisy - sound insulation & distance from bedrooms required.

What is a "plant room" anyway...maybe it doesn't need to be separate from other functional areas (i.e. utility).

There are indeed a lot (too many!) doors.

 

@Blooda's questions: "Ent" is the sole entry to the house other than via the garage. My better half, who is of course in overall charge, doesn't want the utility visible as one walks in the front door.

@Bozza I'm a little reluctant to stick it in the garage as any heat lost there is gone. If it's inside the thermal envelope then it's not lost energy which is useful during the winter...?

@JohnMo architect just stuck the ASHP there. I suspect the detail on the location is TBC; agree it looks like it could be too close to 2 adjacent walls, but theres' plenty of space to move it away.

 

I'm tempted to swap the plant and w/c. But not wall off the plant, just have it as part of the utility. Also loose the door between entry area and circulation area outside the bedroom. That's 2 doors gone  

 

 

[ProDave]

22 minutes ago, Dunc said:

Takeaway thus far:

DHW cylinder will kick out a lot of heat (despite being insulated. Can you box them in with additional insulation?) Probably better not right next to the bedroom.

ASHP/UFH pump can be noisy - sound insulation & distance from bedrooms required.

What is a "plant room" anyway...maybe it doesn't need to be separate from other functional areas (i.e. utility).

There are indeed a lot (too many!) doors.

My 2 pence worth to that:

 

We have our DHW tank in the spare bedroom (one day I will build an airing cupboard around it)  It does not give off excessive heat and does not overheat the bedroom at all.  No further insulation of tank needed, BUT ensure ALL pipework connecting to the tank is well lagged with good thick well fitted insulation, that is where you will get a lot of heat loss if not done properly.

 

We have a noise issue with the water circulation pump being a bit noisy.  It is NOT an issue with where the pump is, but routing of pipes.  In our case the pump is in a different room, but mu "mistake" was routing the main flow and return pipes from the ASHP under our bedroom floor.  Regardless of where the circulating pump is located, it's gentle hum will be transmitted by the pipes.  So keep the pump AND the pipes away from your bedroom.  If I could do it again, the pipes would take a slightly longer route under our en-suite bathroom rather than under the bedroom.

 

We set aside a "plant room" (room above the attached garage) but it ended up not really being used for that.  The only thing in it is the MVHR unit, some electrical controls for the ASHP and the circulating pump.  It turned out MUCH better to site the DHW cylinder in a location central to all points of hot water use, to shorten hot water pipe runs and quicken time for delivery of hot water to the taps.  Try and plan a suitable cupboard for that central to all hot water taps.  Call it "airing cupboard" on your plans.

[Kelvin]

On 21/07/2023 at 21:44, Bozza said:

The single biggest mistake we made with our design was to have the plant room with ASHP internal gubbins pumps etc beneath our master bedroom.  It is very noisy.not the ASHP, just the internal pumps when it is on.  No issue in the summer but a nightmare in the winter.

 

your design has that stuff basically in your bedroom.   which will be even worse.

 

***Strongly*** suggest you move it over towards or even inside the garage.  Also consider what is above it.   put acoustic insulation in the plant cupboard including ceiling.

 

Learn from my mistake.

 

 

 

 

Completely agree. In our previous house the DHW tank, diverter valves, and main circulation pump were all in a big cupboard outside our bedroom door. Not specifically noisy but everything is noisy in the dead of night. This time everything is in a plant room in a separate part of the house. It does back onto the study which might eventually become a bedroom which isn’t ideal but it will only have occasional use. 
 

We have no pipework routed within our bedroom other than the MVHR ducting to the living room but that is under the floor of the coom wall that runs through the bedroom. 

Edited July 23, 2023 by Kelvin

[Marvin]

Hi @Dunc

 

I believe that if you have digital thermostats and protect all electric cables through the insulation you can increase the insulation around the tank. Well, actually that's exactly what we did on our vented cylinder 2 years ago. But as @ProDave just commented about: we found out that insulating pipes to within an inch of their lives made a surprising difference.

 

We have no problem with pump noise with either the primary or secondary circuit pumps.

 

The recommendations are to keep everything, except the box with the fan, INSIDE the thermal envelope. I would recommend insulating external pipes really, really, well.

 

Will you need a buffer tank?

 

Your biggest running cost going forward will probably be for heating the building. The design of heating systems has become more and more complicated and more and more exacting over the last 100 years and ASHP's are at the forefront of this. In the middle of winter you may have the outside temperature at  -5°C and you want the water heated to 55°C.

 

If the only things between these temperatures on the outside pipes is a layer of copper and 13mm of foam good luck with that! 

 

Keep the external pipework to a minimum.

 

I would design a section of the garage at the back right to be within the thermal envelope and fit the ASHP on the garage back wall connecting to all the heating, hot water gubbins there and get rid of the plant room and make an airing cupboard in the rearranged area with a small radiator.

 

Good luck.

 

Marvin.

 

[JohnMo]

12 minutes ago, Dunc said:

ASHP/UFH pump can be noisy - sound insulation & distance from bedrooms required.

1, you are doing UFH do you need an UFH pump and mixer? This could be deleted and use the circulation pump in the ASHP. Unless you intend to make lots of zones and install a buffer.

 

1 hour ago, Dunc said:

My better half, who is of course in overall charge, doesn't want the utility visible as one walks in the front door

 

Is she ok with guests walking through the utility to get to the toilet? Would it be better swooping WC and store around, so toilet access is from the hall.

[ProDave]

8 minutes ago, JohnMo said:

 

Is she ok with guests walking through the utility to get to the toilet? Would it be better swooping WC and store around, so toilet access is from the hall.

Or do what we did, make Utility and downstairs WC all in one room.  I could not find a way to make a WC and utility accessible from the hall without making the hall bigger to accommodate another door and waste space with corridors, or go through one room to get to the other, so I decided on just one room that contains washing machine, tumble dryer, sink, clothes airer and WC.  Building control were happy with that, the space of the clothes airer is our potential future downstairs shower allocation and if we did fit a shower we would then partition it to a smaller utility room that you walk through to get to the shower room.  But prefer it all open just now.