How to find heat loss by experiment
How to find heat loss by experiment
(OP)
I'm trying to verify the accuracy of some software that calculates heat transfer through buildings. This is to be done by some practical experiment, but I'm not quite sure how to set it up, so I want peoples ideas on this. I'm thinking of using a room, its u'values, heating devices, and the adjacent rooms for some measurements. On paper I can calculate the heat loss in Watts using basic equations, but how can I somehow support the calculations by doing an experiment?





RE: How to find heat loss by experiment
RE: How to find heat loss by experiment
With a known I^2R there is a new equilibrium room temp (and hopefully, negligible increases in the surrounging temperatures).
Theta = measured temp-calculated temp
Plot the theta-vs the added heat generation.
Regards
RE: How to find heat loss by experiment
in any case... you do all the calculations, very carefully... considering all factors and alternatives... and then the HVAC OEM says: we have available: 5, 10 or 15 ton equipment, make your pick.
saludos.
a.
RE: How to find heat loss by experiment
RE: How to find heat loss by experiment
The heater output at steady state during each isothermal hold gives the heat flux for a given ΔT.
The increased or decreased heat input needed to change the room T can be used to approximate the room's heat capacity.
Re windows. No problem in doing the heat flux measurements as described; maybe more correction for room heat capacity.
Repeat the measurement cycle with one window blocked off or replaced with polystyrene insulation.
Maybe then repeat with a second window insulated off.
Ditto if a third window.
Perhaps start with the polystyrene sheets loosely stacked in the room so always contribute to the heat capacity.
RE: How to find heat loss by experiment
There are many building energy software packages out there, and some have been validated against models. Some of these have been publically funded, so the details of the validation method should be available to the public.
Alternatively, validate your software against some already validated and accepted software. Much easier.
RE: How to find heat loss by experiment
m777182
RE: How to find heat loss by experiment
If the inflow/outflow of air to the central room can be cut off---
Then with additional I^2*R bring the room up to its original temperature. Add this I^2*R to other heat generation in the room to get the total heat flow.
Regards
RE: How to find heat loss by experiment