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Subject Author Date
Thermally Controlled Diffusers Will 12-30-2007
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Posted by Will on December 30, 2007, 7:48 pm
Which brand of thermally controlled diffusers offer the widest range of
temperature set points? In particular I would like to find a way to set
temperature between 69 and 71 for a unit that has both heating and cooling
thermostats built in.

Acutherm makes the Therma-Fuser product, and it has a set point range
between 70 and 78.

I'm also interested in finding alternative products that have digital wall
thermostats to allow the end user to have some input into the thermofuser
set points. Acutherm appears to have this.

If there are any brands to avoid I would appreciate knowing about those as
well.

--
Will



Posted by Zyp on December 30, 2007, 8:23 pm
Will wrote:
> Which brand of thermally controlled diffusers offer the widest range
> of temperature set points? In particular I would like to find a way
> to set temperature between 69 and 71 for a unit that has both heating
> and cooling thermostats built in.
>
> Acutherm makes the Therma-Fuser product, and it has a set point range
> between 70 and 78.
>
> I'm also interested in finding alternative products that have digital
> wall thermostats to allow the end user to have some input into the
> thermofuser set points. Acutherm appears to have this.
>
> If there are any brands to avoid I would appreciate knowing about
> those as well.
>
> --
> Will

Anything that limits the air flow through the diffuser is not good for the
equipment. Generally, when there is less than the recommend airflow, it is
condsidered abuse by the manufactuer.

I realize that many believe that zone controlled diffuers [new to the
market - some wireless] will solve poor duct design, but nothing is further
from the truth.


--
Zyp



Posted by Will on December 31, 2007, 4:11 am
> Anything that limits the air flow through the diffuser is not good for the
> equipment. Generally, when there is less than the recommend airflow, it
is
> condsidered abuse by the manufactuer.

I think the Acutherm wireless thermostat for their therma-fuser just alters
the set point on the thermostats inside the diffuser. It doesn't alter
airflow directly?


> I realize that many believe that zone controlled diffuers [new to the
> market - some wireless] will solve poor duct design, but nothing is
further
> from the truth.

Sometimes it is not an airflow problem. Sometimes the problem is a large
area is on one zone and the thermostat placement for the zone doesn't
accurately represent temperature variations across different rooms.

And the therma-fuser gives each room occupant at least some ability to
establish a personal preference a bit warmer or colder than the set point on
the zone thermostat. I know some large companies here in the Bay Area like
Adobe put a therma-fuser on every outlet vent going into an employee's work
area.

--
Will



> Will wrote:
> > Which brand of thermally controlled diffusers offer the widest range
> > of temperature set points? In particular I would like to find a way
> > to set temperature between 69 and 71 for a unit that has both heating
> > and cooling thermostats built in.
> >
> > Acutherm makes the Therma-Fuser product, and it has a set point range
> > between 70 and 78.
> >
> > I'm also interested in finding alternative products that have digital
> > wall thermostats to allow the end user to have some input into the
> > thermofuser set points. Acutherm appears to have this.
> >
> > If there are any brands to avoid I would appreciate knowing about
> > those as well.
> >
> > --
> > Will



Posted by Noon-Air on December 31, 2007, 8:14 am

>> Anything that limits the air flow through the diffuser is not good for
>> the
>> equipment. Generally, when there is less than the recommend airflow, it
> is
>> condsidered abuse by the manufactuer.
>
> I think the Acutherm wireless thermostat for their therma-fuser just
> alters
> the set point on the thermostats inside the diffuser. It doesn't alter
> airflow directly?

Just how do you think they work if they don't alter airflow directly???

>> I realize that many believe that zone controlled diffuers [new to the
>> market - some wireless] will solve poor duct design, but nothing is
> further
>> from the truth.
>
> Sometimes it is not an airflow problem. Sometimes the problem is a large
> area is on one zone and the thermostat placement for the zone doesn't
> accurately represent temperature variations across different rooms.

Unless the thermostat is placed on a window or in the other end of the
building from where the zone is, thats not really an issue, neither is the
size of the space. What IS the issue is proper airflow and distribution.
There are minimum airflow requirements for a/c systems.. usually around
400CFM per ton. If you increase or reduce the airflow by as little as 10%,
the consequenses can be disasterous. too little airflow, and the system will
freeze up, too much airflow and you have high humidity...that creates its
own set of problems. FWIW, a correctly sized system, with a properly
installed air distribution system will maintain a constant, even temperature
throughout the zone....usually within 1 or 2 degrees.

> And the therma-fuser gives each room occupant at least some ability to
> establish a personal preference a bit warmer or colder than the set point
> on
> the zone thermostat.

They don't work like that.

> I know some large companies here in the Bay Area like
> Adobe put a therma-fuser on every outlet vent going into an employee's
> work
> area.

As far as I can tell, either your trying to put a band aid on poorly
designed, badly installed, air distribution system(ductwork), or you
spamming these "smoke and mirrors" defusers. which is it??



Posted by Will on December 31, 2007, 1:03 pm
> >> Anything that limits the air flow through the diffuser is not good for
> >> the
> >> equipment. Generally, when there is less than the recommend airflow,
it
> > is
> >> condsidered abuse by the manufactuer.
> >
> > I think the Acutherm wireless thermostat for their therma-fuser just
> > alters
> > the set point on the thermostats inside the diffuser. It doesn't alter
> > airflow directly?
>
> Just how do you think they work if they don't alter airflow directly???

Thermafusers alter the airflow as a result of an internal thermostat
responding to airflow temperature around the thermostat. The wireless
thermostat on the Acutherm unit appears to alter the setpoint temperature of
that thermostat.


> > And the therma-fuser gives each room occupant at least some ability to
> > establish a personal preference a bit warmer or colder than the set
point
> > on
> > the zone thermostat.
>
> They don't work like that.

Room A on Zone 1 can set the thermofuser to close its damper below 70 and
above 72.

Room B on Zone 1 can set the thermofuser to close its damper below 71 and
above 74.

That certainly does affect the end temperature in each of those two rooms.
It's not active heating or cooling from the therma-fuser, but it is
certainly giving the room occupant some level of control on the end
temperature, and at least it sets limits.


> > I know some large companies here in the Bay Area like
> > Adobe put a therma-fuser on every outlet vent going into an employee's
> > work
> > area.
>
> As far as I can tell, either your trying to put a band aid on poorly
> designed, badly installed, air distribution system(ductwork), or you
> spamming these "smoke and mirrors" defusers. which is it??

Badly designed, badly installed, badly redesigned, badly maintained systems
with bad ductwork describes about 90% of the small commercial buildings that
are 20 years old. And no one ever has the $3K to $10K budget to redo a
zone. Usually the customer has a problem with a single room even *after*
everything is rebalanced.

In any case, I was looking for brand recommendations for thermally
controlled diffusers. I wasn't trying to convince anyone to use one.

--
Will




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