New self build design, heat and architect

[G and J]

18 minutes ago, JohnMo said:

UFH cooling was the thermostat on wall only reads a couple of degrees cooler. But you feel way cooler and more importantly the whole building gets back to a nice temperature way quicker.

This was certainly our experience as 'newbies' ...very pleased with it, and certainly much, much better than we had expected.

 

2 hours ago, MikeSharp01 said:

We never saw an upstairs temperature, in the roof apex, above 27,  never got to 29,

This is very similar to our numbers, and certainly we kept the temps below those that others were experiencing, but still way too hot to sleep comfortably which is what we're hoping for.

 

Also worth saying that although it doesn't really cool, by reducing the humidity any given temp doesn't feel as hot as it would have done in our previous house.

[SteamyTea]

1 hour ago, JohnMo said:

The floor surface becomes cooler than your body, its primary cooling method is a radiant heater in reverse

Really.

May work if you suspend yourself naked a few mill above the floor.

 

[saveasteading]

1 hour ago, JohnMo said:

you are thinking the wrong way

That's my usp.

 

1 hour ago, JohnMo said:

floor sucks the heat from you.

I get that.

My feet are at 36°C so even the recent heatwave has been lower.

Cooled floor at what? 16?

 

So it's a feel-good for the feet, if choosing to go barefoot, but it hardly cools the body. And it's the air temperature that we need cooler. Don't we want to be at 18°C max for deep sleep?

 

It's a luxury to have cool feet and go barefooted ( I find that unpleasant on hard surfaces)  and that's an individual choice.

[-rick-]

1 hour ago, saveasteading said:

So it's a feel-good for the feet, if choosing to go barefoot, but it hardly cools the body. And it's the air temperature that we need cooler. Don't we want to be at 18°C max for deep sleep?

 

You're wrong. Cooler feet has a huge impact on how you feel overall. I don't have UFH but do live in a building that suffers from cold floors/cold air layer at floor level in winter.

 

The thermometer can read 23/24 at table level but 16C at feet level. In that situation I feel fairly cold.

 

1 hour ago, saveasteading said:

It's a luxury to have cool feet and go barefooted ( I find that unpleasant on hard surfaces)  and that's an individual choice.

 

Nothing to say you need to be barefoot. Wear socks if you want, even open light slippers. You'll still feel much cooler in a space with a floor that is noticeably cooler than the air temp.

 

Edit: Frankly, given my experience I suspect even if you wore whatever outside clothes you were comfortable with I suspect you'd still feel the cooling effect from a cool floor, just maybe not as pronounced.

Edited yesterday at 11:12 by -rick-

[JohnMo]

1 hour ago, saveasteading said:

That's my usp.

 

I get that.

My feet are at 36°C so even the recent heatwave has been lower.

Cooled floor at what? 16?

 

So it's a feel-good for the feet, if choosing to go barefoot, but it hardly cools the body. And it's the air temperature that we need cooler. Don't we want to be at 18°C max for deep sleep?

 

It's a luxury to have cool feet and go barefooted ( I find that unpleasant on hard surfaces)  and that's an individual choice.

So let me rephrase 

 

imagine walking into an old stone church, it feels way colder in summer than it's actual temperature. Underfloor cooling feels similar.

 

2 hours ago, SteamyTea said:

Really.

May work if you suspend yourself naked a few mill above the floor.

 

No naked suspension needed. Or certainly never heard of anyone with floor cooling going to that effort, but maybe... well not go into what you maybe get up to.

[Oz07]

22 hours ago, JohnMo said:

We have a plant room, but you really don't need one. An MVHR unit can be located in a cupboard same as the UFH manifold or in the utility, the hot water cylinder just needs to find a space 

But that will obviously for heating (but can do cooling) so you don't need planning permission.

With the mvhr you do need to get the 5 or 6" supply and extract pipes to an external wall and around 2m apart. Plus all your ducting. So its not quite as easy as popping in a cupboard. I'm not trying to be pedantic its just these do take up a bit more room once you allow for connections. Have to be strategically placed too. 

[JohnMo]

52 minutes ago, Oz07 said:

around 2m apart

Not required if you use a combined/directional inlet outlet. One of our two MVHR units is in the middle of the house, the two ducts effectively go in void above built-in wardrobes to the outside wall. Our manifolds are in the same void. But it only feeds two bedrooms and extracts from two bathrooms.

[SBMS]

9 hours ago, saveasteading said:

That's my usp.

 

I get that.

My feet are at 36°C so even the recent heatwave has been lower.

Cooled floor at what? 16?

 

So it's a feel-good for the feet, if choosing to go barefoot, but it hardly cools the body. And it's the air temperature that we need cooler. Don't we want to be at 18°C max for deep sleep?

 

It's a luxury to have cool feet and go barefooted ( I find that unpleasant on hard surfaces)  and that's an individual choice.

We’ve gone fancoils upstairs and UFH downstairs. Dual zone setup on Ashp so we can run the fancoils with proper chilled water in hot temperatures.  Hoping we will be in in next few months and will report back in summer if it works!!

[saveasteading]

10 hours ago, SBMS said:

report back in summer if it works!!

And if it doesn't quite? It should work well.

[Oz07]

11 hours ago, JohnMo said:

Not required if you use a combined/directional inlet outlet. One of our two MVHR units is in the middle of the house, the two ducts effectively go in void above built-in wardrobes to the outside wall. Our manifolds are in the same void. But it only feeds two bedrooms and extracts from two bathrooms.

Never heard of them. Are they limited to smaller systems? Why do you have 2 units?

[saveasteading]

12 hours ago, JohnMo said:

combined/directional inlet outlet. 

They would need rather a strong flow speed to ensure the expelled air is sent clear. It's simple hydraulics so presumably that's been factored in.

I once discounted mvhr totally because none of the manufacturers had thought of this. In those says the heat exchangers were inefficient too.

That mostly explains my resistance to mvhr... but 15 years or so is a long time for things to improve at the expense of early adopters. 

[JohnMo]

1 hour ago, Oz07 said:

Never heard of them. Are they limited to smaller systems? Why do you have 2 units?

You can get from 125mm to 200mm so should cover all domestic properties.

https://www.paulheatrecovery.co.uk/product-category/mvhr-ducting/terminals-external/

 

Two MVHR units was just simple. Our house is 25m long and to save too many long duct runs I picked up two Titon units from eBay for peanuts. I also used coanda supply nozzles to reduce and simply duct runs/length and used 90mm duct to make double runs limited.

[JohnMo]

2 minutes ago, saveasteading said:

They would need rather a strong flow speed to ensure the expelled air is sent clear.

A ran for a year at minimum speed and never saw any mixing going on by monitoring temperature. Out flow is rejected horizontally outwards, inwards flow comes from below and the sides, so out flow has a hard job making it's way back in.

 

[Oz07]

6 minutes ago, JohnMo said:

A ran for a year at minimum speed and never saw any mixing going on by monitoring temperature. Out flow is rejected horizontally outwards, inwards flow comes from below and the sides, so out flow has a hard job making it's way back in.

 

Cool. What do you have 2 holes through the wall and they just connect into these? Neat solution. I went through roof tiles at my last place. How did you get on with your SAP with the titon units did you buy these before the design stage or did you change your as built SAP to allow for them?

[JohnMo]

We go through icf wall, so pre installed plastic ducts before the concrete pour.  You have the two ducts with an 50mm or so gap between them.

 

No issues with SAP, like the Titon units as they are UK manufacturer and the you can actually talk technical to a person on the same wave length. Buying cheap I had a speed signal issue on one of the motors, parts arrived the next day to fix with instructions. Great service.

 

Being Scotland we do a sap at design and completion. I had all the routes of ducts all designed in during design and I actually bought the 2x MVHR units at the design stage, prior to getting the as designed sap. So no issues.

[Great_scot_selfbuild]

7 hours ago, JohnMo said:

I had all the routes of ducts all designed in during design

I'm impressed. I had a real challenge trying to get this done. Principal Designer wasn't really up to this level of detail, and the design I had from the MVHR provider was ok but really very simplistic not far off the level of detail seen by UFH providers producing their off-the-shelf layouts. I was still happy with them overall because the cost was so competitive, but I can empathise with others about the challenge of getting a detailed design of duct and service runs.

[Tony L]

Could you share the name of your MVHR supplier please, @Great_scot_selfbuild.  I'm in Surrey too, & it would be good to speak with a supplier that's had a BH recommedation.

[JohnMo]

38 minutes ago, Great_scot_selfbuild said:

impressed. I had a real challenge trying to get this done. Principal Designer wasn't really up to this level of detail

DIY'ed all the key points of the design. Didn't really ask for much help from so called experts

[Great_scot_selfbuild]

1 hour ago, Tony L said:

MVHR supplier

CVC Systems - https://cvcsystems.co.uk

 

I know that some others on here have used them too (I believe positively). I've attached a couple of screenshots of the design document - although my comment above was a little critical, it was a lot better than anything I was likely to get from the PD.

[SBMS]

12 hours ago, saveasteading said:

And if it doesn't quite? It should work well.

It will