Plant room in loft, possible?

[jayc89]

Perhaps a crazy idea...

 

We have a cold loft space, hipped roof, plenty of room centrally, but drops off quite a bit towards the eaves. I plan to reinsulate it with blown cellulose and board it out. Our MVHR will also go up there, so I need to think about insulated ducting where it's not buried beneath the insulation. 

 

We currently have a 200L unvented cylinder which we occasionally run low, predominantly on Sunday's after we've washed the roast pots and everyone wants a shower (we could change our schedule but...) my suspicion is that this problem will only get worse as the kids get older, so will eventually look into a larger capacity cylinder, which wouldn't fit in its existing location. (airing cupboard). 

 

Would it be possible to make a room up there, using some stud walls, insulating them to effectively give me a plant room. All pipes etc would be ran from beneath buried in the insulation, coming up through this new room's floor. Which would avoid the need for me to think about insulated ducting etc for my MVHR, it also means I can mount my MVHR manifolds somewhere accessible opposed to beneath the insulation. I'd also have somewhere to relocate the hot water tank too, and potentially even the boiler if I wanted to. By my calcs the room would be approx 4m x 4m and  the ceiling height would be around 3m, so plenty of space, whilst still allowing for ventilation across the roof timbers. 

 

Cold/freezing conditions aren't a problem as everything would either be beneath the loft insulation, or within the insulated room. What I'm not sure on is summer conditions, the slates turn the loft into an absolute oven, last year being fiercely hot, is there a risk of the services in this box room overheat, specifically the MVHR, and gas boiler, if I was to move it up there? Would the room itself need some sort of cooling/ventilation? 

[Alan Ambrose]

It sounds good to me and I'm planning to put all our PV stuff in a similar space - and in the next place MVHR too. I don't know what geometry you have but it strikes me that this is potentially a very easy way to route MVHR ducting into some rooms.

 

I guess it lengthens the UFH pipes a bit and means they want to be well lagged. 

 

The one thing you might need to check is adequate support for anything particularly heavy - e.g. cylinders and/or PV batteries.

 

The gas boiler will, of course, need a vent / flue but shouldn't be generating a lot of heat when the weather is hot.

 

Heat impacts the reliability of all modern-day electronics (e.g. the control boards), so it would be helpful to figure out a mechanism to stop them from getting crazy hot.   

[jayc89]

16 hours ago, Alan Ambrose said:

It sounds good to me and I'm planning to put all our PV stuff in a similar space - and in the next place MVHR too. I don't know what geometry you have but it strikes me that this is potentially a very easy way to route MVHR ducting into some rooms.

 

I guess it lengthens the UFH pipes a bit and means they want to be well lagged. 

 

The one thing you might need to check is adequate support for anything particularly heavy - e.g. cylinders and/or PV batteries.

 

The gas boiler will, of course, need a vent / flue but shouldn't be generating a lot of heat when the weather is hot.

 

Heat impacts the reliability of all modern-day electronics (e.g. the control boards), so it would be helpful to figure out a mechanism to stop them from getting crazy hot.   

 

PV gear is a good shout too. 

 

What's the best way to keep a room in a cold loft cool during the summer months?

[jayc89]

Finally coming back to this. The roof has 2x King Post Trusses that span the full house width, sitting on external walls (330mm thick). There are no internal load bearing walls. Distance between the two trusses is approx. 2.5m.

 

I'm thinking of running some joists between the trusses at 400 ctrs for the make shift plant room to house;

 

- MVHR unit

- water manifolds

- unvented cylinder

- Grundfos HomeBoost (potentially)

 

at some point I’ll run the idea past our SE before cracking on, but does this seem plausible? Can I put a load bearing floor on the trusses, or do I need to put in some new beams just for this purpose? (Getting them up there would be a PITA)

[joe90]

The biggest thing is the UVC which (depending on size) which will be heavy being full of water, the rest won’t be a problem but your SE will give a definitive answer.

[jayc89]

It’s a 300l cylinder, 330kg when full. 530mm diameter.  
 

Joists would be spec’d for up to 1.25 kN/m2 load so should be good, but that load would then be spread across the existing trusses which may or may not be a good idea?

[JohnMo]

Would it cheaper to run the immersion on a Sunday morning to charge the cylinder to higher temp - more capacity sorted. I am assuming your on a heat pump?

[Alan Ambrose]

Coming back to this - perhaps you need some specific support for the cylinder as the joists will do about 125 Kg/m^2 and the cylinder weight will be concentrated on say a m^2, assuming it sits, say, on a m^2 bit of thick ply. I've recently twigged that there is a bit of fire risk with PV inverters, and a bit extra with batteries - so that and the weight of the (future) batteries may need to be considered too.

[Temp]

Bear in mind that some service engineers won't work in lofts. Think it's mostly the ones where you pay a monthly fee and they come do an annual service. I suggested to a relative that they ask the engineer to put fernox in the system and they refused saying they weren't allowed to go up into the loft to tip it into the header tank.

 

[Andehh]

Also don't over look the possibility plant rooms can be noisy & directly over a bedroom could cause annoyances!