Heating and Cooling Sy= stems Chapter
12
A great pl= easure of trawler cruising over sailing is the ability to be warm in the cold weat= her and cool in the heat.
|
T |
he heating and ventila=
tion
system is composed of a closed loop glycol system that circulates through t=
he
ship. Each area of the ship h=
as an air
handler and thermostat that transfers the heating or cooling from the glycol
loop to air and distributes conditioned air to the area it serves. The closed loop glycol system is c=
ooled
or heated by the Marine Air chillers/heat pumps in the engine room. When the sea water temperature exc=
eeds a
certain level, the heat pump is no longer effective heating. For these situations the Hurricane
diesel furnace is switched into the loop for high efficiency diesel heating=
.
![](3D"HVAC_files/image002.jpg")
Air
Handlers
The ship has eight air=
handlers
that serve the various living areas as shown in the table, below. Each of these units is sized to ha=
ndle
the heat and cooling load for the area.&nb=
sp;
Each area has a control panel in the area near the occupants to sense
the temperature and direct the operation of the air handler to supply coole=
d or
heated air to achieve the set temperature.=
Operation of these panels is found in their own user manual.
Each air handler has v=
alves
on the heated/chilled glycol pipes so it can be isolated for service or sho=
uld
a leak develop. A condensate =
drain
runs from each air handler to the gray water tanks. Sometimes condensate drains do not=
carry
enough volume to rest getting plugged.&nbs=
p;
This is the most likely source of any moisture accumulation around t=
he
air handler. When servicing t=
he
glycol loop, air may infiltrate the loop.&=
nbsp;
If this is the case or a particular air handler does not seem to res=
pond
as well as others, then the unit may require bleeding. There is a bleed valve on a small =
tube
on the accessible side of each air handler.
|
Handler |
Location |
Areas Served |
Handler Size |
|
Saloon |
Starboard
cabinet base |
Saloon |
xx CFM |
|
Galley |
Port forw=
ard
corner cabinet base |
Galley |
|
|
Pilot House |
Under set=
tee |
Pilot Hou=
se |
|
|
Forward Stateroom |
Under bed=
|
Forward
stateroom and forward head |
|
|
Port Stateroom |
Base of
wardrobe cabinet |
Port Stat=
eroom |
|
|
Office |
Cabinet u=
nder
breakers |
Office and
master head |
|
|
Master Stateroom |
Under bea=
d |
Master
stateroom |
|
|
Engine Room |
Ceiling f=
orward
of engine |
Engine ro=
om |
|
Air Handling/ Circulation
Heated or chilled glycol is delivered to the air han= dlers via the glycol plumbing system. The glycol mix is heated or cooled by the chillers and furnace. A ball valve for the chiller and f= or the furnace selects which unit supplies glycol to the system. The supply lines run across the ce= iling of the engine room and utility room. They are routed down the forward wall of the utility room, to the bi= lge and then travel the length of the ship in the bilge. At points along the bilge the air handlers tee into the supply line and the return line. The return lines follow the same p= ath back to the engine room, drawn by the circulation pump on the return line.<= span style=3D'mso-spacerun:yes'> A flow indicator in the return lin= es permits observation of proper flow.
There is a gray accumulator tank near the chillers, = with a valve for fresh water feed, plumbed into the domestic water system to top up the glycol system. The fresh = water is fed into the system automatically through a pressure reducer and a check valve to prevent back flow into the glycol system. If the glycol system drops below 8= PSI, the ship’s fresh water system will add water through the reducer to b= ring it to 8 PSI. Operational PSI = may be greater than 8 PSI due to expansion when heating occurs. This is normal. See the Marine Air manual for proper operating conditions. There is also a valve for glycol fe= ed into the system should that need topping up. See Marine Air Manual for instruct= ions.
If topping up the system with fresh glycol solution = when the closed loop circulation system is pressurized, you will need a charge p= ump to pump the glycol solution into the system. Check the glycol solution for = its degree of concentration with an ordinary automotive coolant hydrometer. See= the Marine Air Manual.
![](3D"HVAC_files/image004.gif")
The closed loop plumbing for the chilled (or heated)= water system is a high heat resistant CPVC schedule 80 plastic pipe with foam pipe insulation around it. If opening the system for plumbing repairs, use CPVC Schedule 80 or equivalent piping. Ordinary PVC piping will not withstand the high temperature of the Hurricane boiler heated water.
Air Conditioning
The air conditioning system is all 220 VAC powered. = You must be connected to an adequate shore power source or run a generator when operating the air conditioning chillers.&n= bsp; Breakers for the chillers and pump relay panel are in the utility ro= om panel.
The A/C system has its own inlet and seawater strain= er in the engine room, located at the forward starboard side of the engine room b= elow the fuel transfer manifold. Before operating the A/C system, be sure the va= lve for the sea water inlet is open, then check the flow indicator for proper f= low during operation. The seawater cooling circulating pump is near the inlet strainer.
The second air conditioning pump, mounted on the sta= rboard engine room wall, circulates the chilled (or, if in heat mode, heated) glyc= ol to the air handlers. Be sure the valves for this pump are open for operation and that the flow indicator shows proper flow.
There are two valves above the chillers, in the insu= lated piping. For cooling or heating from the heat pump, both the supply and retu= rn valves must be opened for the chillers and the return for the Hurricane die= sel fired boiler must be closed. = The supply from the boiler must be open to permit expansion. See Hurricane diesel fired boiler = below.
The main control box for the A/C system is in the engine roo= m, adjacent to the chillers. Change the toggle switches from off to cool for a= ir conditioning. For reverse cycle heating, change to heat. The middle toggle switch must be set to chiller.[WW1]
The breaker for the circulation and raw water pumps is on th=
e bulkhead
above the white toggle switch box.
It must be switched on for cooling or heating or boiler operation.
The system cannot be operated without the boat afloa= t, with the sea water inlet fully immersed. Before starting up the system, che= ck to see that the inlet and outlet valves for the raw water cooling pump are open.
Hurricane Diesel Fired Boiler
The diesel fired boiler is tied to the Marine Air circulation system. To run the furnace instead of the chiller, open the two blue handled valves in the black insulated piping located above the Hurrica= ne boiler. Each has a label indicating the position of the valves for boiler operation or for Marine Air chiller operation. Close the return valve to the chiller units to take them out of the loop. Leave the supply side open to perm= it expansion.
The furnace is fueled from the ship’s day tanks through the utility room fuel manifold.&nb= sp; The furnace is plumbed to be continuously bled with the bleed return line plumbed to the starboard day tank.&nb= sp; When operating the furnace, open the valve on the diesel fuel distribution manifold in the utility room for the Hurricane heater. Since t= he bleed line will return to the starboard day tank, the starboard day tank su= pply to the manifold must also be open to prevent overflowing the day tank.
The battery charger on the forward engine room bulkhead for = the main engine start battery should be plugged in whenever the Hurricane boile= r is in operation. Failure to do s= o may run down the main engine start battery.[WW3]
Open the smokestack on the starboard aft stairs by rotating = the top counter clock-wise. [WW4]
Go to the engine room main control panel for the A/C system and switch the two outside toggle switches to off, and the middle sw= itch to boiler.
Turn on the breaker for the circulation pump just ab= ove and beside the main control panel on the engine room bulkhead, labeled ‘A/C P/P Breaker’. At the utility room panel, the chiller breakers should be off, the PRP= (pump relay panel) should be on[WW5] , and the desired air handler breakers should be on.
Pull ‘ON’ the red (push/pull) switch labeled Hurricane boiler on the panel above the air conditioning chillers. There will be a pause, the fuel pu= mp will come on, and then the burner will fire a few seconds later. Set the desired temperature at the= air handler control panels as usual. &nbs= p; [WW6]
The boiler will produce heat in a few minutes. Remem= ber that heating the glycol mixed chilled water in the system may take some time before heat comes out the air handlers.