Small shower room with MVHR, how long will it be wet?

[Adsibob]

We have a pretty small space we are trying to make into a wet room. It is 1690 long by 1648 wide and about 2.5m high. So almost a square in terms of the floor space.

One of the considerations in choosing the optimal layout is how important is it that stuff doesn’t get wet. ie. is it better to put the vanity unit or the toilet opposite the shower. The toilet is obviously fully water resistant (except the toilet paper) whereas the vanity unit is made from wood, oiled to make it shower proof, with a counter top sink occupying almost the entire top surface.

We will have MVHR so the room should dry very quickly. The plant room for the MVHR is actually directly next to this shower room, so quite easy to double up the extraction ducting in case this speeds up drying time.

 

 

[joth]

As you are looking to dry the room through evaporation. The evaporation process requires  energy (converting sensible to latent heat and all that) and airflow, so i think the main question is where you anticipate the energy to come from.

Do you have UFH in that room? Another heating source? Will it run all year, or just in winter?   UFH is most effective as the water tends to pool on the floor so the UFH directly heats it to help evaporate. A towel radiator, for example, less useful for the puddles on the floor (but obviously very useful for drying the towels, again another source of damp and energy demand for evaporation)

Does the room have windows? Will direct sun light be coming in during the times you expect to be showering? This is probably the best scenario.

Doubling up extraction will pull more air in from the rest of the house, in effect  using the warmth of the  rest of the house as the heat source, lowering the effective efficiency of the MVHR system overall. 

 

[Adsibob]

13 hours ago, joth said:

As you are looking to dry the room through evaporation. The evaporation process requires  energy (converting sensible to latent heat and all that) and airflow, so i think the main question is where you anticipate the energy to come from.

Do you have UFH in that room? Another heating source? Will it run all year, or just in winter?   UFH is most effective as the water tends to pool on the floor so the UFH directly heats it to help evaporate. A towel radiator, for example, less useful for the puddles on the floor (but obviously very useful for drying the towels, again another source of damp and energy demand for evaporation)

Does the room have windows? Will direct sun light be coming in during the times you expect to be showering? This is probably the best scenario.

Doubling up extraction will pull more air in from the rest of the house, in effect  using the warmth of the  rest of the house as the heat source, lowering the effective efficiency of the MVHR system overall. 

 

There will be UFH, probably no towel heater. I hadn’t actually thought that through. Maybe I va need a towel heater as well. 
There is a small 750 by 900 window which will get a bit of sun in the afternoon.

I guess I was looking for approximate estimates of drying times based on others’ experiences. 

Edited August 27, 2021 by Adsibob

[tonyshouse]

There won’t be a problem even if you get it wrong 

 

One inlet and one outlet would be belt and braces approach