TWL: Fw: ENGINE ROOM TEMPS
I am sure my boats engine room is to hot.
I would be very interesred in hearing what the tempretures run in the engine
room of members boats, as well as size, type and manufacturer of there
blowers...
I am considering installing larger blowers in my engine room and would like
to hear a formula for figuring blower size needed for the cubic feet in
engine room.. Also a source for dc blowers other than vestus...
Also is it better to have one blower blowing in and one blower blowing out?
Or is it better to have both blowers blowing out or blowing in?
I sure could use some help here... Thanks
Mike Danforth
Steffie Ann 52' Defever L.R.C.
Daytona Beach Fl.
I understand that the engine room shouldn't be more than 30 degrees F. over
ambient outside temp. Of course, for diesels, the cooler the better. My
Krogen has one high capacity blower blowing in.
Keith
__
Slogan of 105.9, the classic rock radio station in Chicago: "Of all the
radio stations in Chicago...we're one of them."
----- Original Message -----
From: biplane1@iag.net
The blowers should exhaust air. You want a negative pressure in the engine
room so hot air or fumes aren't escaping into the boat through any crevices
or when you open the door.
We added two blowers horozintally at overhead height that circulate air
within the engine room. It makes it "feel" much more plesant when you're in
there and moves the hot spots around so they get exhausted.
115 volt blowers are ten times more reliable than DC, last longer and are
much cheaper. If you have an inverter let it run from the DC and use it to
run the blowers. If necessary purchase and dedicate an inverter just for
that function - what you save on blowers will more than pay for the
inverter. You can use a cheap industrial inverter without all the charger
features because it only runs when the engines are on anyhow. Eg Harbor
Freight, 2000 watt inverter $239.99.
Andina Foster,
tech@yandina.com
I am sure my boats engine room is to hot.
I would be very interesred in hearing what the tempretures run in the
engine
room of members boats, as well as size, type and manufacturer of there
blowers...
I am considering installing larger blowers in my engine room and would
like
to hear a formula for figuring blower size needed for the cubic feet in
engine room.. Also a source for dc blowers other than vestus...
Also is it better to have one blower blowing in and one blower blowing
out?
Or is it better to have both blowers blowing out or blowing in?
I sure could use some help here... Thanks
Mike Danforth
Steffie Ann 52' Defever L.R.C.
Daytona Beach Fl.
115 volt blowers are ten times more reliable than DC, last longer and are
much cheaper. If you have an inverter let it run from the DC and use it
to
run the blowers. If necessary purchase and dedicate an inverter just for
that function - what you save on blowers will more than pay for the
inverter. You can use a cheap industrial inverter without all the charger
features because it only runs when the engines are on anyhow. Eg Harbor
Freight, 2000 watt inverter $239.99.
Andina Foster,
UPDATE: Harbor freight have 600 watt inverters on sale for $70.
I've found that you have to take those ratings with a grain of salt but that
should run four 100 watt blowers with power to spare.
Andina Foster,
tech@yandina.com
Mike Danforth wrote:
I am sure my boats engine room is to hot.
I would be very interesred in hearing what the tempretures run in the engine
room of members boats, as well as size, type and manufacturer of there
blowers...
I am considering installing larger blowers in my engine room and would like
to hear a formula for figuring blower size needed for the cubic feet in
engine room.. Also a source for dc blowers other than vestus...
Also is it better to have one blower blowing in and one blower blowing out?
Or is it better to have both blowers blowing out or blowing in?
I sure could use some help here... Thanks
REPLY
Most of the large yachts I get on board have engine room fan systems made by
Delta "T" in Florida.
They can provide you with some design figures to determine the requirements for
your boat.
The typical system consist of one in and one out blowing fan.
The speed is variable and controlled by a sophisticated variable frequency
source.
The speed is determined by temperature and in some cases barometric pressure.
When a pair of MTU V12 engines are running at full bore they can draw so much
air that the negative pressure in the engine room would prevent you from
opening the door to get inside unless there is sufficient outside air being
brought in.
On the other hand some of the big fans can produce so much air flow it would
bowl you over if you stood right in front of the fan outlet.
If you store the starting batteries inside the engine compartment they should
not be subjected to ambient temperatures in excess of 120 F
Hotter than that and you risk a condition called thermal runaway when the
batteries are being charged hard.
SeaRay ran some tests on their boat models and confirmed that their engine
compartment did not get hotter than 120 F since this is a stipulated criteria in
the ABYC standard. Please note I am only reporting what the standard says, not
necessarily agreeing or refuting it..
New engine installations by Caterpillar, Detroit, MTU etc all require extensive
barometric and temperature measurements to be made during the commissioning in
order for the warranty to be valid.
Boats that are repowered quite often have to have additional air inlets added
in order to bring the engine compartment environment into spec.
That tells me that the older boats were quite often under ventilated and
perhaps over heated.
You need not buy sophisticated instrumentation to do these measurements
yourself.
Engine inlet barometric pressure can be measured using a home made manometer
consisting of a yard stick, twenty feet of thin PVC plastic tubing and a piece
of 3"X1" board. Temperature can be measured using the inexpensive
indoor/outdoor thermometers you can buy in any hardware or automotive shop for
under $20.
Calibrate the temp sensor with ice water and boiling water. Its a fair
assumption that the electronic sensing circuit is linear between these two
points.
The engine manufacturer can provide the numbers for acceptable engine intake
barometric pressure and temp.
Unless these numbers are achieved, then you can figure on adding ventilation.
Companies like Delta "T" can give you help in calculating air flow as a
function of engine compartment volume.
BTW, keep in mind that corrugated flexible air duct has many time more flow
resistance than smooth walled duct.
regards
Arild
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.507 / Virus Database: 304 - Release Date: 8/4/2003
I would be very interesred in hearing what the tempretures run in the
engine room of members boats, as well as size, type and manufacturer of
there blowers...
In the PNW, I have a single large Volvo (TMD100A) that eventually, after 8
hours running, gets up to 109 (measured with a Fluke digital meter &
thermocouple) with an ambient water temperature of 60 and an air temperature
of 80. This is with natural ventilation into the engine room through two
vents in the hull side and no blowers running. If I run the two Jabsco
exhaust blowers - through two other vents - I can bring the ambient air temp
down to about 100.
Keith
These are the ones we used. They are fairly easy to install with the flange
around the exit that will screw to the overhead with a round or square duct
above it.
Go to http://www.grainger.com and insert part number 4C447 in the "Product
Searach" box at the top.
Andina Foster,
tech@yandina.com
Andina,
Any suggestions on where to purchase some 115volt blowers?
Jeff
biplane1@iag.net wrote:
I would be very interesred in hearing what the tempretures run in the engine
room of members boats, as well as size, type and manufacturer of there
blowers...
Mike,
My engine room runs about 115 degrees, summertime. No genny running. No
blowers. Just natural flow. Can not remember temps with genny running, but
I do that very seldom due to inverter. Size: approx. 17x12x7.
Bob
R C Smith Jr
M/V MARY KATHRYN
Hatteras 58 LRC
Annapolis
My engine room temp, in Florida where the ambient air temp is around 90F
and water temp is about 85F, runs about 120 degrees F, with two Lehman-Ford
90s running at 1800 rpm, no blowers operating. In the Chesapeake, where the
ambient air temp was around 85F and the water temp around 70F, the engine
room temp was about 110-115F, no blowers operating.
I do have two 300 CFM squirrel-cage blowers sold by the big boat stores
that I turn on after shutting down the engines. They are located at the
forward end of the engine room and exhaust the air. Originally, one blew in
and the other out, but the temp gets lower faster with both blowing out;
air enters the engine room through vents and a long bilge that provides
some ventilation through the lazarette. Engine room is about 8 feet X 12
feet X 3.5 feet high.
At 08:30 AM 9/6/2003, biplane1@iag.net wrote:
I am sure my boats engine room is to hot.
I would be very interesred in hearing what the tempretures run in the engine
room of members boats, as well as size, type and manufacturer of there
blowers...
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
Bob McLeran and Judy Young Manatee Cove Marina
M/V Sanderling Patrick Air Force Base
Hampton 35 Trawler Melbourne, Florida
Andina,
Any suggestions on where to purchase some 115volt blowers?
Jeff
We added two blowers horozintally at overhead height that circulate air
within the engine room. It makes it "feel" much more plesant when you're in
there and moves the hot spots around so they get exhausted.
115 volt blowers are ten times more reliable than DC, last longer and are
much cheaper.