Any advice on heat recovery fans from Vent Axia and how good thier "h" humidity function works?

[diy_massacre]

When I moved into my house we had mould behind furniture upstairs so I bought a dehumidifier which did the trick.
I found the cooker hood was on recirculate. I then ducted it to outside and the dehumidifier is now redundant.
Don't forget that for an extractor to work you need air to come in! I've worked in numerous buildings where fans were in sealed rooms. One had a 9" Ventaxia which you could hear speed up whenever the door was opened!

Thanks, food for thought!

I could try and connect the cooker hood to the outside but he piping wouldn't look pretty and think the management may not like the outcome.

The house leaks air like a sieve with air coming in everywhere, we have ledge and brace bent doors which plug a gap but dont seal, so it can only get better.

Thanks

diy_m

 

[Ric2013]

Thanks Ric2013

I like your response, thats a good datapoint!

I always assumed the humidity detector would be on the internal inflow to the unit inside rather than the incoming air. But interesting so hear about the sensor not being able to distinguish.

Thanks

diy_m

Crossed wires here. It will monitor the air inside the room. However, the air in the room will be replaced with outside air which may have a high RH. So the 'new' air in the room may also seem damp to the sensor. The fact that your fan will preheat the incoming air will certainly help it distinguish, however, the very act of heating the air will cause the RH to fall somewhat.

 

[gmartine]

If you're prepared to drill a hole through the outside wall for a humidity fan why is it a problem for an extractor fan?

It seems you're attracted to a particular solution that isn't even designed for kitchens and the problem you say is damp. You can get low profile ducting that can sit on top or even inside kitchen cabinets quite unobtrusively if you have tradtional fitted style kitchen. A full cooker extractor system ducted to the outside is what you need.

 

[Dannyk]

I'd never heard of these humidity fans till seeing this thread. They seem to be a poor expensive solution looking for a problem.
Cost £300!
Extraction a mere 9l/s compared to a cooker hood's 111l/s or a 6" kitchen fan's 200+l/s (cost<£100).
gmartine is right.
I eventually sited the hob on outside wall on a refit.

 

[Murdoch]

I eventually sited the hob on outside wall on a refit.

Good move

These days mandatory external extraction IS required on new builds AND extensions for kitchens, cloakrooms, utility rooms, en-suites and bathrooms

 

[hometech]

Been using these for the last 8 months in bathrooms, kitchen and utility room. I swapped all existing fans for them. Expensive but well worth it. My plan is to add them to all rooms and lofts as well. Ventilation is so badly neglected

 

[gmartine]

Been using these for the last 8 months in bathrooms, kitchen and utility room. I swapped all existing fans for them. Expensive but well worth it. My plan is to add them to all rooms and lofts as well. Ventilation is so badly neglected

Why bother installing a heat recovery fan in a room where there's no high humidity/temperature to recover the heat from.

 

[Ric2013]

Why bother installing a heat recovery fan in a room where there's no high humidity/temperature to recover the heat from.

It depends what percentage of heat is recovered and if you need constant operation. If the fan consumes 5W of electricity and is run constantly, that's 0.13kW per day.

But 9l/s is 32cu m. an hour. So you could be changing all the air in the room once per hour at that rate.

As far as I can gather (very roughly indeed), it takes around 1.2W to heat a cubic meter of air by 1°C. So at 20°C indoors and 10°C outdoors, every day would have 770 cu m x delta 10 x 1.2W = 9.2kWh. Recover half that energy and you've saved 4.5kW. Nearly a pound's worth of electricity if you're a low energy user or on a genuinely green tariff.

So, assuming the fan lasts only 3 years, and assuming a 100 day heating season it is still paying for itself compared with just opening the window. So not a stupid idea at all.

 

[hometech]

Why bother installing a heat recovery fan in a room where there's no high humidity/temperature to recover the heat fromI

I don't expect the average person to understand so no point in discussing that with you

 

[Murdoch]

I don't expect the average person to understand so no point in discussing that with you

Back with your condescending replies again?