If you don’t have an extractor fan in your bathroom, it’s a good idea to get one anyway to prevent moisture buildup from using the shower etc. If you’re worried about heat loss, you can get single-room MVHR extractor fans that get rid of the old moist air, but retain the heat from it (well, most of it). An extractor fan will use a lot less energy than a dehumidifier, so if you have the drying space in the bathroom and are happy to install one, then that might be a good option.
If you get a dehumidifier instead then you are not limited to drying the clothes in the bathroom - just do it wherever is most convenient. We use one to dry our clothes in the spare bedroom, and it works just fine. The main reason we don’t dry them in our bathroom is due to lack of space.
I suggest getting humidity monitors - less than £10 combined with a thermometer. I have several and when they show 70% humidity I turn on the dehumidifier.
Both Ebac and Meaco are good makes, but as Tim Gilbert says “I suggest that you compare power consumption and water extraction rates”.
Also note that different types of dehumidifier work better at different ambient temperatures.
In the case of Meaco their web site has nominal extraction rates for an assumed humidity. In reality there will be a curve with high extraction at very high humidity and negligible extraction at minimal humidity.
This is true when not heating the house but in the heating season you need to take into account the need to heat the cold air drawn into the house to replace the extracted air.
Thanks everyone @Tim_Gilbert@andyham@epickering@tom and @lloydham for all your feedback in helping me understand the best approaches for managing humidity.
I’m particularly interested in the Ebac dehumidifier - mostly because it’s British made and I want to chase them up to discuss their service for enabling parts and repairs.
Embodied carbon and lifecycle to waste feels just as important as the energy efficiency of anything we choose to install in our homes.
This is the reason I’m so wary of insulating and using materials that if they fail cannot be recycled or support the oil industry in the production of them.
I’m looking at a single room wall mounted MVHR for the bathroom. Mostly to dehumidfy when drying clothes and heat exchange for when we’re in the bathroom would be a good additional extra if the energy consumption is low. I want to keep it simple and have full control to turn on and off with ease.
Obviously, as you stated - the most energy efficient version would be good for the environment and our pocket.
I think making a comparison table is a good thing to help me.
What should I include?
Energy used in KWHs, price, functions (some join up with lights when turned on /off), heat output, manufacturers guarantee… anything else?
If you have managed to make your home nearly airtight, and possibly otherwise, I strongly recommend a continuous system with humidistat to increase flow when it is wet in the room. Given your bathroom’s recent history there is all the more reason to have constant ventilation, starting now, not at a late stage of the refurbishment.
The link you provided had one continuous system. Armed with the above information you may find others elsewhere.
Things to take into account when choosing an MVHR are
Volume of the room
Rate of air change by the unit when idling and when boosting
Watts used
% recovery declared (take with a pinch of salt)
Size of opening required in the wall. (For airflow bigger is better, for ease of fitting often smaller is better.)
Length of guarantee
Cost
At least a continuous system doesn’t need linking to the lights.
As a reference, my whole house system has a declared consumption of 32W but when boosting I have measured 37W. Still good.
Edit: all single room systems seem to be through the wall, rather than ceiling vented (with appropriate duct).
You won’t find this published as it is largely dependent on duration of use rather than efficiency of system. Also consider that energy used should be compared with energy saved.
I was about to post about drying clothes in an efficient way, then found this thread. We was using a C rated vented dryer in our detached brick garage for drying clothes in winter. This was starting to cost a lot in electricity, but also the dryer has stopped working in the recent cold weather. We are currently drying the clothes indoors but this is making the house humid. We don’t have space in the house for a dryer, I would like to have a heat pump dryer, but putting any dryer in the garage is a bad idea in cold weather.
So is the best solution to get a dehumidifier to use in one room?
We purchased an ebac 1300 dehumidifier with a laundry setting. It’s great. We dry our clothes in the bathroom.
The dehumidifier is great as it’s portable. We use it in one of our bedrooms, which has a moisture and mould problem. It’s really helped this winter because we’ve hardly had the heating on to dry the moisture.
Recently I have found out about decentralised MVHR’s, i wonder if these are a good idea, but they seem costly per each unit.
Dehumidifiers seem to be always out of stock at the moment.
I recommend MVHRs. They not only remove humidity but also give fresh air, while recovering the heat in the exhaust air. There is a discussion of suitable models on another thread.
In the above linked thread this comes out a winner
I suggest you skip down the thread and find someone who can advise about fitting, although my understanding is that once the right size hole has been cut through your wall any electrician can fit one.
Makes my life so much easier 