There are a couple right answers. Here's an approach I've used:
* System type UHT
* Zero out fan energy (0.00 kW/CFM), if there are no space circulation fans tied to your IR heater operation
* eQuest doesn't simulate the skin-heating comfort effects of radiant heat. If you run into unmet heating hours, you can justifiably lower associated thermotat setpoints to account for this.
* DOE2 help files advise adjusting your HIR to 1.05 if products of combustion are not being vented out of the space (industrial applications).
I've used the following approaches to model overheat gas radiant heating
systems.
Since doe-2 does not have models for heating that is predominantly radiant
in nature; the assumption I use for the heating models are that the
predominant gain mechanism is convection.
I assume the system is well modeled by using a heating coil in the space,
such as a baseboard system (which has no flow).
If the heater is constant output when on then you could use a reset
controlled baseboard with a flat output relation.
If they are space temperature controlled then you use thermostat control.
Both would be good models.
If control is variable based on people sense of comfort then you need a
relationship between space temperature and comfort and then alter the
thermostat schedule to match that relation.
If the radiant heater does not have any fan associated with it, like a radiant ceiling panel, then I zero out the fan energy like Nick mentions. When the radiant heater has a combustion air fan, like a gas-fired radiant heater, then I enter fan data that matches the combustion air fan to capture that energy consumption.
________________________________
Keith Swartz, P.E., LEED AP
Hi Arash,
There are a couple right answers. Here's an approach I've used:
* System type UHT
* Zero out fan energy (0.00 kW/CFM), if there are no space circulation fans tied to your IR heater operation
* eQuest doesn't simulate the skin-heating comfort effects of radiant heat. If you run into unmet heating hours, you can justifiably lower associated thermotat setpoints to account for this.
* DOE2 help files advise adjusting your HIR to 1.05 if products of combustion are not being vented out of the space (industrial applications).
~Nick
[cid:489575314 at 22072009-0ABB]
NICK CATON, P.E.
Arash,
I've used the following approaches to model overheat gas radiant heating
systems.
Since doe-2 does not have models for heating that is predominantly radiant
in nature; the assumption I use for the heating models are that the
predominant gain mechanism is convection.
I assume the system is well modeled by using a heating coil in the space,
such as a baseboard system (which has no flow).
If the heater is constant output when on then you could use a reset
controlled baseboard with a flat output relation.
If they are space temperature controlled then you use thermostat control.
Both would be good models.
If control is variable based on people sense of comfort then you need a
relationship between space temperature and comfort and then alter the
thermostat schedule to match that relation.
Dennis
___________
Dennis Hunt
Arash,
If the radiant heater does not have any fan associated with it, like a radiant ceiling panel, then I zero out the fan energy like Nick mentions. When the radiant heater has a combustion air fan, like a gas-fired radiant heater, then I enter fan data that matches the combustion air fan to capture that energy consumption.
________________________________
Keith Swartz, P.E., LEED AP