Review
of direct, indoor and outdoor vent
7.4 series - PH-28R models
There are three Paloma tankless water heater models from 7.4 series
that we will review in this article. All three models are high volume,
on demand water heaters, designed to provide an endless hot water,
instantaneous and only when you need it. With the newest technology
implemented,
Paloma
7.4 line gas models are high efficient and great performers.
With the respect of venting option and installing location, 7.4 Paloma
tankless water
heaters can be divided into next models:
PH-28R DVSN(P) (P for propane) that is using
direct venting option
PH-28R IFSN(P) for indoor installation
PH-28R OFN(P)
for outdoor installation
All 7.4 series on demand models are able to work with maximum gas
input of
199,900 BTU/hr and are considered as high efficiency water
heaters, with the energy factor of 0.82 and thermal efficiency 84%.
This is mainly done with a
help of
the intelligent electronic system, designed also to provide high
safety environment for the unit and users.
These high volume units, with 314 gallons of hot water per
hour, are able to provide enough hot water for up
to three simultaneous showers and supply middle size residential homes.
Use this value as a reference for
southern, warmer areas (Sunbelt), where incoming cold water temperature
is 60 F; in northern and colder areas, where incoming water is 40 F and
the supply is 5.2 gallons per minute.
In order to start and protect the water heater at the same
time, minimum cold water flow has to be
met, which is for PH-28R models 0.66 gallons per minute and minimum
pressure of 14
psi.
At the same time to prevent inner parts from malfunctioning, maximum
allowed
water pressure is 150 psi. TPR valve, which is must to installed, was
designed and tested on that pressure.
With a gas modulating valve, PH-28R Paloma tankless water heater
adjusts its
power, based on the water flow demand and temperature, and it can work
in a range from minimum 19,000 to 199,900 BTU.
Maximum hot water temperature is factory-set on 120 F but it
can be adjusted to up to 140 F for residential models.
7.4
Series Paloma
Tankless Water Heater - Venting Options
7.4 Paloma outdoor
models cannot be installed indoors and in any other position except
vertical. Due to negative influence of cold weather and freezing
temperatures, recommendation is to protect your tankless water heater,
hot and cold water lines with a proper insulation.
7.4
Paloma indoor
tankless water heaters are to be installed indoor only. For the proper
work and safety, a proper venting material has to be mounted on the
heater, with a termination suitable for Category III venting.
Indoor models, PH-28R IFSN (P), are using one-pipe system to
discharge flue gases, 4" in
diameter, UL approved and Category III stainless steel, while the air
for combustion is used from the inside. Fresh air must be supplied
through two equal openings properly sized, either from the outside or
other room. Venting pipes can be run horizontally or vertically
and with an adequate termination.
Recommendation is to install a vent with a slight downward slope of
horizontal run toward the outside so the formed condensate can securely
leave the unit. If the downward slope is not possible, or the pipe is
run vertically, than condensate trap has to be installed.
As these models are installed indoor there is always potential
hazard of carbon monoxide leak. That is why Paloma is using an
exclusive sensing burner and ICAD safety system not only to optimize
combustion and make the unit greener, but to shut the water heater down
in case of raised level of carbon monoxide.
Paloma direct
vent water heaters, PH-28R DVSN, must be installed with a 2/4"
diameter, UL approved
and Category III coaxial stainless steel vent pipe, horizontally or
vertically run and with a proper termination.
Other
Benefits
7.4 Paloma
tankless water heater can be connected with another residential gas
unit to gain even more
power, by using DUOnex Cable that has to be purchased separately.
Combining its power, the First Hour hot water supply will reach amazing
516 gallons, while 100 gallon tank type will have only 135 gallons max.
7.4 series tankless water heaters are using an ignition device which
automatically lights the burner and eliminates the need for pilot light
and energy waste. It is very easy to use, and together with built-in
electric blower contributes in rising the thermal efficiency.
Paloma tankless water heater 7.4 brings also computerized self
diagnostic program and error code display, which helps in
troubleshooting and repairs.
Using the manual and error code on the unit; like 11, 12, 15, you can
define what is the possible cause (valve is not open, low water flow,
low gas pressure...) and how to repair it (open the faucet to increase
the flow, or call the service).
Other benefits and safety features can also be found in the article
about Paloma water
heating here.
You can buy Paloma tankless water heater from 7.4 series
online at Amazon.com
or www.pexsupply.com
from $900 or in Home Depot both Canada
and US. Keep in mind that 7.4 series qualifies for the 2009 Federal
Tankless Tax Credit as it is EnergyStar rated.