I live in an air-conditioned mobile home.

There are no return ducts.
Air is returned to the furnace in the utility room.

Some rooms are quite cooler than others,
so I've closed the outlets in those rooms.

Friends tell me that if you close the outlet ducts,
theres a chance of freezing up the cooler coils.

Possible ??

Any rule-of-thumb for measuring/avoiding this ?


rj

wrote:

I live in an air-conditioned mobile home.

There are no return ducts.
Air is returned to the furnace in the utility room.

Some rooms are quite cooler than others,
so I've closed the outlets in those rooms.

Friends tell me that if you close the outlet ducts,
theres a chance of freezing up the cooler coils.

Possible ??

Any rule-of-thumb for measuring/avoiding this ?

As a rule of thumb, if it freezes up then you've closed too many vents.

hvacrmedic

"RJ" wrote in message
...

I live in an air-conditioned mobile home.

There are no return ducts.
Air is returned to the furnace in the utility room.

Some rooms are quite cooler than others,
so I've closed the outlets in those rooms.

Friends tell me that if you close the outlet ducts,
theres a chance of freezing up the cooler coils.

Possible ??

Any rule-of-thumb for measuring/avoiding this ?


rj

This is Turtle.

Years ago there was 2 rules of thumb about closing vents.

1] don't do it.

2] Never close more than 1/3 the volume of air off or 1/3 of the number of vents
in your home.

TURTLE

"TURTLE" wrote in message
...

"RJ" wrote in message
...

I live in an air-conditioned mobile home.

There are no return ducts.
Air is returned to the furnace in the utility room.

Some rooms are quite cooler than others,
so I've closed the outlets in those rooms.

Friends tell me that if you close the outlet ducts,
theres a chance of freezing up the cooler coils.

Possible ??

Any rule-of-thumb for measuring/avoiding this ?


rj

This is Turtle.

Years ago there was 2 rules of thumb about closing vents.

1] don't do it.

2] Never close more than 1/3 the volume of air off or 1/3 of the number of
vents in your home.

TURTLE


I could never understand this, when you close off unused rooms aren't you
lessening the load on the system over all? In heating and air-conditioning?
Or is it worse for one verses the other??

Thanks, Rich

"Rich" wrote in message
I could never understand this, when you close off unused rooms aren't you
lessening the load on the system over all? In heating and
air-conditioning? Or is it worse for one verses the other??

Thanks, Rich

Yes, you are, but the systems are designed to run at a certain capacity. If
the capacity is not used, they will cycle more frequently. Is that bad?
Depends. Compressors are often rated at X starts per hour.

You have to understand about load on the system. With few exceptions of
some variable machines, the heater or AC compressor is either off, or it is
on. The thermostat is a switch that turns it off or turns it on. There are
those people that when chilly will turn the thermostat up higher thinking it
will heat faster. No, it won't. When you turn on a light in a room, it is
on. Pushing the switch harder does not make it brighter. Same with a
heating and cooling systems. Burner on is putting out full capacity.

Shutting down dampers will change the air flow and static pressure on the
blower. If it has a lot of resistance, it can actually work harder trying
to overcome the blocked vents as it would just blowing and circulating the
air. Just like blowing through a straw, bigger is easier.
Ed

"Rich" wrote in message
g.com...

"TURTLE" wrote in message
...

"RJ" wrote in message
...

I live in an air-conditioned mobile home.

There are no return ducts.
Air is returned to the furnace in the utility room.

Some rooms are quite cooler than others,
so I've closed the outlets in those rooms.

Friends tell me that if you close the outlet ducts,
theres a chance of freezing up the cooler coils.

Possible ??

Any rule-of-thumb for measuring/avoiding this ?


rj

This is Turtle.

Years ago there was 2 rules of thumb about closing vents.

1] don't do it.

2] Never close more than 1/3 the volume of air off or 1/3 of the number
of vents in your home.

TURTLE


I could never understand this, when you close off unused rooms aren't you
lessening the load on the system over all? In heating and
air-conditioning? Or is it worse for one verses the other??

Thanks, Rich


You unblance the air flow that was designed into the ductwork.
Now, that said, mobile home units are different animals.
What the OP needs to do, since the air handler that is in the unit is made
to operate on a higher static, is to start with the ducts closest to the air
handler, and almost close them, not fully, but almost. As he gets farther
from the unit, (air handler) the ducts should be progressivly open till the
registers at the farthest end, are open all the way. Air, being fluid, goes
for the path of least resistance, and this will insure max air flow to the
farther ends of the home, while still allowing for cooling and heating to
take place.

On Thu, 4 Aug 2005 15:09:08 -0400, "Carolina Breeze HVAC"
wrote:


"Rich" wrote in message
ng.com...


You unblance the air flow that was designed into the ductwork.
Now, that said, mobile home units are different animals.
What the OP needs to do, since the air handler that is in the unit is made
to operate on a higher static, is to start with the ducts closest to the air
handler, and almost close them, not fully, but almost. As he gets farther
from the unit, (air handler) the ducts should be progressivly open till the
registers at the farthest end, are open all the way. Air, being fluid, goes
for the path of least resistance, and this will insure max air flow to the
farther ends of the home, while still allowing for cooling and heating to
take place.

Thats basically what I ended up doing.

I closed the vents closest to the furnace intake.
Full-open the ducts furthest away.

House temps feel alot more balanced room-to-room now.



rj

Edwin Pawlowski wrote:

"Rich" wrote in message

I could never understand this, when you close off unused rooms aren't you
lessening the load on the system over all? In heating and
air-conditioning? Or is it worse for one verses the other??

Thanks, Rich


Yes, you are, but the systems are designed to run at a certain capacity. If
the capacity is not used, they will cycle more frequently. Is that bad?
Depends. Compressors are often rated at X starts per hour.

You have to understand about load on the system. With few exceptions of
some variable machines, the heater or AC compressor is either off, or it is
on. The thermostat is a switch that turns it off or turns it on. There are
those people that when chilly will turn the thermostat up higher thinking it
will heat faster. No, it won't. When you turn on a light in a room, it is
on. Pushing the switch harder does not make it brighter. Same with a
heating and cooling systems. Burner on is putting out full capacity.

Not as a general rule, since many systems are staged.


Shutting down dampers will change the air flow and static pressure on the
blower. If it has a lot of resistance, it can actually work harder trying
to overcome the blocked vents as it would just blowing and circulating the
air.

Doesn't work that way. The blower will unload with greater static.

Just like blowing through a straw, bigger is easier.

Lower resistance with a constant applied force means more work, not less.

hvacrmedic

Edwin Pawlowski wrote:

"Rich" wrote in message

I could never understand this, when you close off unused rooms aren't you
lessening the load on the system over all? In heating and
air-conditioning? Or is it worse for one verses the other??

Thanks, Rich


Yes, you are, but the systems are designed to run at a certain capacity. If
the capacity is not used, they will cycle more frequently. Is that bad?
Depends. Compressors are often rated at X starts per hour.

You have to understand about load on the system. With few exceptions of
some variable machines, the heater or AC compressor is either off, or it is
on. The thermostat is a switch that turns it off or turns it on. There are
those people that when chilly will turn the thermostat up higher thinking it
will heat faster. No, it won't. When you turn on a light in a room, it is
on. Pushing the switch harder does not make it brighter. Same with a
heating and cooling systems. Burner on is putting out full capacity.

Not as a general rule, since many systems are staged.


Shutting down dampers will change the air flow and static pressure on the
blower. If it has a lot of resistance, it can actually work harder trying
to overcome the blocked vents as it would just blowing and circulating the
air.

Doesn't work that way. The blower will unload with greater static.

Just like blowing through a straw, bigger is easier.

Lower resistance with a constant applied force means more work, not less.

hvacrmedic

Edwin Pawlowski wrote:

"Rich" wrote in message

I could never understand this, when you close off unused rooms aren't you
lessening the load on the system over all? In heating and
air-conditioning? Or is it worse for one verses the other??

Thanks, Rich


Yes, you are, but the systems are designed to run at a certain capacity. If
the capacity is not used, they will cycle more frequently. Is that bad?
Depends. Compressors are often rated at X starts per hour.

You have to understand about load on the system. With few exceptions of
some variable machines, the heater or AC compressor is either off, or it is
on. The thermostat is a switch that turns it off or turns it on. There are
those people that when chilly will turn the thermostat up higher thinking it
will heat faster. No, it won't. When you turn on a light in a room, it is
on. Pushing the switch harder does not make it brighter. Same with a
heating and cooling systems. Burner on is putting out full capacity.

Not as a general rule, since many systems are staged.


Shutting down dampers will change the air flow and static pressure on the
blower. If it has a lot of resistance, it can actually work harder trying
to overcome the blocked vents as it would just blowing and circulating the
air.

Doesn't work that way. The blower will unload with greater static.

Just like blowing through a straw, bigger is easier.

Lower resistance with a constant applied force means more work, not less.

hvacrmedic