Product Overview

Submittal Data Information
Variable Speed Delta-T 00
®
Circulators
Submittal Data # 101-133
Supersedes: New
Effective: 11/01/08
Optimal Pumping Simplified
No matter how good your original system design and heat loss calculations were, they included
estimates and rules of thumb. What are the design conditions for those systems you “inher-
ited” or have to service? Have a zone valve system or multi-zone radiant manifolds running off
a common circulator? Your system needs a circulator that automatically adjusts to deliver the
optimal heat transfer based on the actual operation of the system, every day, under all load con-
ditions – even when those conditions change.
With the Taco Variable Speed Delta-T 00
®
Circulators you simply dial in your desired tempera-
ture drop across the system or zone (5-50°F), attach a supply and return sensor directly to the
pump and it will automatically vary its performance to deliver optimal heat, efficiency and com-
fort.
Applications
There are a few hydronic applications that can benefit greatly from the use of a Taco Variable
Speed Delta-T Circulator.
Example 1 : Multi-Zone Radiant
Manifolds with Loop Actuators
Residential radiant floor heating systems
often feature several zones on a single
manifold, using manifold valve actuators,
designed around a 10° Delta-T. The cir-
culator is sized to provide enough flow
and head pressure to satisfy all zones
calling at the same time. At any given point, however, a single, small zone, such as a bathroom
or bedroom, may be the only zone calling, with a required flow rate of only, say, 0.4 GPM. The
attached 008 circulator, however, can generate over 9 GPM. The result? Poor heat transfer and
performance due to a greatly reduced delta T, as well as considerable velocity noise – both likely
resulting in callbacks from unsatisfied customers.
The solution? The 008-VDT or 0013-VDT for larger systems! It will automatically adjust the
circulator’s speed to maintain the proper heat transfer by maintaining a 10˚Delta-T across the
radiant zone. The 00-VDT will also eliminate velocity noise by slowing the actual flow rate
through the zone to the minimum required to deliver proper heat. If other zones on the mani-
fold open, the 00-VDT will increase its speed to deliver the required BTU’s, while at the same
time maintaining the designed for 10° Delta-T across the radiant system.
Example 2: Series Loop Systems Using Zone Valves
As with the previous example, the circulator for this system is sized to provide enough flow
and head pressure to satisfy all zones calling simultaneously under design conditions. As zone
valves close, less heat
is required. But with a
fixed speed circulator,
the open zones will see
an increase in flow, with
a corresponding drop
in the design delta T of
20°. This will result in
poor heat transfer and
considerable velocity noise. In addition, when using a cast-iron boiler, the higher return water
temperatures may cause the boiler to short-cycle, reducing its overall efficiency and resulting in
higher fuel bills for the customer.
The solution? The Taco 00-VDT circulator will automatically adjust its speed to maintain the
designed for 20˚delta T across the open zones. The circulator will speed up or slow down as
needed, as zones open or close, always maintaining a 20˚ Delta-T. This will increase overall com-
fort and sharply reduce boiler short-cycling. The 00-VDT will also control velocity noise issues
in the system, eliminating the need for a pressure differential bypass valve.
See www.taco-hvac.com for additional applications for the 00-VDT Circulators.
Product Features
 •All-in-OnePump&Control
 •SensorsIncluded
 •EasytoInstall:
- Attach 2 Sensors
- Dial in the Desired Delta-T
 •ULApproved
 •Snap-inPCBoard,replaceable
 •LEDStatusPanel
 •FuseProtected
 •Plug-inLowVoltageWiringTerminal
 •OptionalIntegralFlowCheck(IFC
®
)
Operational Benefits
 •IncreasesSystemEfficiency
 •PumpAlwaysRunsat  
Minimum Required Speed
 •EliminatesVelocityNoise
 •EliminatesNeedforaPressureBy-passValve
 •ConservesEnergy
 •AchievesSystemDesignGoals,evenwhen
Installed System Varies from Original Design
 •PumpAutomaticallyAdjuststo 
Current System Conditions
 •SpendLessTimeFiguringOut 
Pressure Drop (for proper pump sizing)
when Servicing Existing Systems.
 •PumpExercise
 •DeliversIdealBTU/hrHeatTransfer 
for All Styles of Emitters
FOR INDOOR USE ONLY
Taco Inc., 1160 Cranston Street, Cranston, RI 02920 / [phone] / Fax [phone]
Taco(Canada)Ltd.,8450LawsonRoad,Unit#3,Milton,OntarioL9T0J8/(905)564-9422/Fax(905)564-9436
www.taco-hvac.com
iSeries-R
B
C
A
B
C
A
“00”-VDT
Supply
Sensor
Return
Sensor
M M M M
Outdoor
Sensor
Boiler
Sensor
"00"-VDT
Supply
Sensor
M
M
Return
Sensor
M
Use at 40%, Centered (In place of “Do it Once. Do it right” on Catalog Sheets) NOTE: Remove Hydronic Components & Systems