Running Engine Blowers

Please re read you own post at No 18, you have clearly stated that those engines can run with no blowers . I was curious as to how the engine room was cooled in that instance and now you tell me how the blowers work.

When I'm thinking of an issue that involves the design and set up of the boat, my first question would go to the builder. How did they engineer it and anticipate it working. Then I would test their design theories to see if they worked as intended.

Another question. Why aren't all engine rooms air conditioned? I don't mean down to 70 degrees, but some air. Could often just be the vents beyond the last vents. No thermostat, just air off the rest of the system.

Just tied up in Ft Myers. Catching up on home things.
Thank you for submitting a spec sheet. From Cat and not from the boat mfg, but I look forward to study it, hopefully later tonight.

Thx,
rc

The inter/after coolers will do the work in their place. Cool ERs don't mean much after the air goes thru a Turbo (and DDC blower).
Coolant thermostats will keep the blocks at 180 degrees no mater how cool the ER is.
Cool ERs are for the human I/O part on/in a ship.

I remember Spellbound had A/C in the engine rooms 20+ years ago. The owner ran them constantly (F Lee B). He was quite upset that is was still hot in there. Duh...
It did make a difference after a few hours at the dock. With engines just turned off, you could go in there (stand up, mid ship ER) and feel the cool air trying to blow on you.

Help the engines run,, NOT.

I wasn't suggesting based on helping the engines although it might in some minor way, but really for the human element. Just surprises me how few engine rooms have air.

Part of the marine tech physical fitness program not to cool the ER; Drink lots of beer (rum), sweat it off the next day, always come home skinny.
Repeat.

I have in my shed an old 24Kbtu s/c unit that one day I will install in out Bert. Been sitting for years. Already ran the wires and temp connected a 230Vac home A/C blower.
But one day, I'll be fancy like da rich folks and finally install that unit.

The amount of energy, cost and space required to make a major difference is what I am sure deters most.

There are some boats that do however cool the air coming into the machinery spaces buy having heat exchanger ( looks like a radiator core) mounted in the Air inlet trunking which is fed by sea water.

Not all engines have Charge Air Coolers and some if not all have a maximum inlet air temp , the non cooling of the machinery spaces and toughing it out promoted above does not seem to consider that there are other items in the machinery spaces other than the main engines that do benefit from being kept at a sensible temperature.

It will take a massive number of BTUs to cool an ER especially within 18 hours or engine shut down. You re not going to accomplish anything by diverting some air from one of the air handlers in the saloon or nearby stateroom.

To get it even slightly comfortable woudl probably take 36 to 48k BTUs in your average 70-90 footer ER... Probably another 12 to $15k and d try room which is usually even harder to find than $

As to cooling with blowers after a run, when the blowers pull hot air from the ER cooler outside air is brought in thru the vent, it really helps.

So I guess I'll try to sum it up:

• Engines pull a massive amount of air through the engine room.
  
• Aftercooled engines don't care what the ambient air temperature is. People care about ambient air temp, but it can't be controlled when running the boat because of the volume of air vs. heat of engines.
  
• AirCond can help bring the temp down, once back at the dock.
  
• ER blowers are usually to exhaust hot air once the engines are shut down, but some manufacturers will use them to add air to the ER while running.

I'm not a surveyor, but I'll guess that ducting air from the salon to the engine room would not be good from a fumes, fire, and noise perspective. Air intakes in general are a source of onboard noise emanating from the engine room.

I'll add a side note regarding air conditioning in an engine room. I recently added a 24,000btu unit to my engine room since I like to tinker and do much of my own maintenance and this time of year its a sweaty proposition. Engine rooms are designed to ventilate. It may seem obvious, but you will need to devise a way to close the engine room vents to keep the cool air in while at the dock for extended amounts of time. Otherwise, your attempts to cool the area will be futile.

A side advantage is the air conditioning keeps the bilges bone dry, humidity low, and salt air off the machinery.

I had always run the blowers while underway. I'm not sure why exactly. After reading this thread I will just run them after running for cooldown only.

Everything in your engine room will suffer prolonged exposure to elevated temps, you should do your best to keep the temp as low as you can.

I always run my blowers underway and after stopping.

You have received a few comments on running / not running your blowers under way.
As above, lots of comments from senior members from around the world.

I'm not sure but I feel it's a split opinion from all who have contributed.

I do recommend after re-reading all of the above suggestions and comments, it's a you thing. These are good thoughts and suggestions (both ways) but your the owner / operator and will decide on your own.

Tap back on this thread later and tell us what you came up with and how it worked out.

,rc

MV Dirona, a Nordhavn 52, wrote recently about this topic.

The high points are that you can keep the engine room temp at an acceptable level even in 24/7 operation but it is work and takes time until you get it right.

It's like a commercial kitchen.......You ventilate it ,not air condition it. It would take a extremely large amount of AC to cool all the heat rejected by the engines. I would consider pumping AC into the engine room when the engines are off. This would only benefit if you do your own maintenance or your engineer/contractor would love you when he does it.

Actually some commercial kitchens are heavily air conditioned. The most difficult area I air conditioned in business was a commercial laundry and pressing area. We did use very powerful exhaust fans but we also used about three times normal air conditioning tonnage and had very large ducts about every ten feet throughout blowing directly on the operators. We were able to actually get it too cold. It's amazing what you can cool with enough exhaust power pulling the hot air out and enough air conditioning.