heat recovery for laundry room - non mechanical

[richard_leeds]

Hi

I have a traditional venting tumble drier that pumps steam laden air outside.  I'd like to get some heat recovery for this, especially as the exhaust is very damp so there is lots of latent heat recovery potential.

I can only find mechanical whole house mechanical systems.  They cost a fortune, and a fan isn't required because the drier already has a fan.  Is is possible to get a small passive heat recovery units for this sort of application?

Thanks

Richard

[Alan Clarke]

There are some single-room heat recovery units, though these still have a fan.
To get decent heat recovery you need equal flow rates each way through the heat exchanger - if you did rig up an un-fanned extract you'd need to ensure equal air flow inwards. If the drier has an intake connection you can fit a duct to then you could make that the intake (and thus bring in dry air pre-heated by the heat exchanger).

Alternatively, some report reasonable success scrapping the drier altogether and using a single-room heat exchanger to keep the air in the utility room dry, and leave clothes to dry over 24 hours or so.

Alan

[richard_leeds]

Thanks Alan. 

The utility room is just 1.5m x 2.5m, so that's why I thought a passive unit would suffice.  The drier fan would push the wet warm air out, and that in turn would draw the fresh air in.

We do also air dry, but the small windowless basement space isn't the greatest! Now you mention it, the heat recovery would help with that.

Just need to find a small unit...

[Lewis Taylor]

As an alternative here is an idea....

Obtain a small intercooler from a car (turbo desiel cars have these and are available as scrap for a few pounds). For those that don't know an intercooler is akin to a car radiator but for air! It is used in a car to cool the boosted air from the turbo before being fed into the engine to reduce heat and increase the density of the charge.

The outlet from the tumbe dryer could be fed through the intercooler and a small low power fan could then be used to blow air though the intercooler matric therefore recovering the heat from the tumber dryer. A small drain hole could be drilled in the bottom to catch the condensation.

Air from outside could be ducted to the fan to obtain fresh air and allow the intercooler to create condensation inside increasing the efficiency.

The larger the intercooler the more heat that could be recovered.

Slightly "Heath Robinson" but I am sure it would work fairly well!

Lewis

[Alan Clarke]

The small heat recovery unit I had in mind was this sort: http://www.vent-axia.com/range/lowatt-hr25-solo-plus.html which has energy efficient fans running on just 2 watts, designed for continuous operation.

Alan