Free Heat?

[Guest]

You need a biscuit tin, two computer fans cut into the lid, a switch,and a bleed valve. Plus hoses in parralel to the calorifier feed, and whatever ductwork/wiring required. I took the electrical feed from the horn switch.

Ours is housed in the calorifier cupboard at rear of boat, ducted under the bed and exits in the central bathroom. It means on a wet day the bathroom is tropical for defrosting me and drying clothes without/before firing up the stove. With the bathroom door open the whole central portion of the boat is warmed.

Not noticed any drop in engine temp (70), or any downside at all. Go for it.

 

I fitted a bleed valve on a high t-off which means I can easily bleed the heater matrix (ex fiesta) and the calorifier.

 

Peter20120226_18.JPG

Brilliant

[Mike Jordan]

See if this helps- The photos are of a home made housing using pop rivets and ally sheet, a single 125mm computor fan and and the matrix from a ford galaxy ( there are two heaters in a galaxy. This matrix is from the passenger compartment) Computor fans are not as good as those taken from a vehicle but are nice and quiet. The matrix is surrounded with foam to stop it rattling and can be slid into the housing with the pipes facing in either direction.

I have always sited the heater in the base of a cupboard and frequently put a fan in the roof of the cupboard to vent through the roof of the boat. this means that the heater will work in reverse when the fan in the unit is switched off and make the cupboard into a drying space. A 100mm fan normally uses about point one of an amp and can be left on overnight.

Mike.

[Paringa]

I have a 20 plate heat exchanger - ebay - plumbed into my calorifier circuit. A 2 port valve when open allows my central heating pump to pump water around the heat exchanger circuit. The pump and valve are triggered by a switch and relay - the latter installed by Mike BM of this parish. The heat transfer is enough to get the radiators and boat toasty warm on a trip...

 

If you look at the saving on diesel to run heating, time and effort it took to do plus costs, was it worth it? Probably not.

 

But it works and I like to feel I am getting something for free...if you know what I mean.

[Alan Saunders]

On older cars the heater was totally ineffective until the engine warmed up and the thermostat opened. On more recent vehicles the heater is effective within a few minutes. I believe this is because the heater is plumbed into the head cooling circuit? Some 'modern' boat engines may have a similar arrangement?

 

Alan

[Scholar Gypsy]

On older cars the heater was totally ineffective until the engine warmed up and the thermostat opened. On more recent vehicles the heater is effective within a few minutes. I believe this is because the heater is plumbed into the head cooling circuit? Some 'modern' boat engines may have a similar arrangement?

 

Alan

 

Possibly - but see comments above on the risk of overcooling.

[PeterDHS]

Over-cooling might be an issue with a plate exchanger or an attempt to heat radiator circuits. However my install (see previous) was simply air fanned through a Fiesta heater matrix. Cost was about £45 from memory and works brill.

On my 46 ft NB with a 38hp BetaMarine there is no discernable temperature drop whatever.

Best money I have ever spent on the boat (don't get me started on the money-pit issue).

 

Peter.

[Mike Jordan]

I can only report on the results of using these heaters with BMC 1.5 and 1.8 engines. The hot supply was taken from the heater outlet pipe on the cylinder head and the return to an unequal tee in the swim tank return pipe.I never experienced any over cooling. The calorifier seemed to reach full temperature in about 45 minutes of cruising with or without the heater in use at the same time.

I can't recall using the engine to generate power for the batteries without cruising at the same time, I don't think its good practice, and wouldn't expect to get the engine warmed up quickly enough to generate waste heat to warm the cabin.

A very popular modification in the eyes of management was a modest length of 100mm lightweight hose to provide a hair drier. Probably not worthwhile today since everyone seems to have an inverter onboard.