Figure I Generalized map of the Wilbur Mining ... - University of Utah

PART II
HEAT LOADS, WELLS. HEAT EXCHANGERS,
AND PUMPS
Heat Load Detennination
Commercial District Heat Load. Since it is impractical
to do detailed heat loss calculations on
each of the downtown buildings, a typical block was
chosen and the total downtown area heat loss projected
from the values obtained.
The typical block was selected to contain a
mix of building construction with particular attention
to materials, number of floors in the buildings,
display windows, and type of business. The
block chosen is bounded by North 7th, North 8th.
Main, and Pine Streets. Building construction is
primarily masonry (brick) with built up roofs and a
good mix of ceiling heights, some of the establishments
having been remodeled with lowered ceilings.
Businesses include an insurance office, two jewelry
stores, two clothing stores (1 men's, 1 women's),
an office supply store, two home furnishing stores,
a photographer's studio, a restaurant, and an outdoor
sporting goods store with office space on the
second floor.
The heat loss of each establishment was calculated
using ASHRAE recommended procedures and design
temperature for the Klamath Falls area. Actual
values used were: inside temperature of 60°F
(with 10°F night setback during the coldest nighttime
periods); and design temperature of 0°F,
which will include 99% of the time. Each establishment
was inspected, measured, and construction
estimated and/or obtained from the building occupants.
Heat losses were estimated based on ASHRAE
values for the materials and construction involved,
with wind speed of less that 7 raph.
Meteorological data was obtained from the U.S.
Weather Bureau downtown station for January, 1978,
and the degree days for the month calculated. Heat
losses for the buildings were again calculated
using the January weather data and estimated fuel
consumption was compared with actual fuel consumption
obtained from building occupants' January
fuel bills. Calculated values were H.9% higher
than actual fuel consumption.
From the information thus obtained, a heat
load constant of 4.34 BTU/H/ft^ based on building
volume was estimated and applied to building volumes
obtained from the City Planning Department.
Fuel consumption and process heat loads were
obtained from special case establishments in the
proposed district. Domestic hot water was estimated
at ^0% of the district heat requirements.
These loads were added to the loads calculated on
the basis of building volume to obtain the total
heat load.
Future expansion was provided for by adding
approximately 12% to the building volume heat load
estimates but no additional high process loads
were estimated since zoning restrictions prohibit
385
Lund, et. al.
such future expansion in the area covered by this
district.
Total estimated heat load for the downtown
district is 135 x 10^ BTU/hr and will require
6,750 gpm of 200°F water with a 40°F temperature
drop.
The heat loads for 10 of the 14 buildings included
in the initial district had been estimated
using ASHRAE methods for the 1977 county feasibility
study. Actual consumption of fuel was compared
against estimated consumption for a period of
5 years for that study. Estimated consumption was
approximately 8% higher than actual consumption.
The heat load values obtained from the 1977
study were within 15,000 BTU/hr of the values obtained
when using the constant of 4.34 BTU/hr/ft^,
The heat load for the Phase 1-14 government buildings
based on the constant is 15,3 x 10^ BTU/hr,
Selection of 40 Temperature Drop, Ten of the
14 initial buil dings presently have hot water heat-
ing systems at average temperatures ranging from
144°F to igO^F, One building is partially heated
by heat pumps s upplied with 100°F water and par-
tially by 190°F water in finned tube convectors.
An electrically heated building obviously will re-
quire a retrofi t to convert to hot water by placing
water coils in the duct plenums.
The county jail has a very old steam system
that is inadequate now, but the existing finned
tube radiation can be utilized with additional
lengths of radiation. Modifications must be made
to enlarge the steam condensate return lines.
The Veterans Memorial Building, also steam,
has combination radiation and forced air heating.
The building has been remodeled and office size
reduced several times with installation of new radiation
so that there is excess radiation capacity
at steam temperatures. Use of 180°F average water
temperature will reduce the radiation capacity but
this loss can be offset by increasing th^ coil capacity
in the central forced air unit.
The hot water heated buildings, in general,
presently have average temperature in the 180°F to
190°F range. Reduction of the average temperature
to 180°F will reduce the heating capacity by about
10%. Since the buildings are old and were originally
designed with over capacity, the present
systems will require little retrofit except in the
mechanical room valving and control systems and
addition of appropriate valves and controls to accept
water from the district supply system.
Use of average v/ater temperatures much below
180°F would require the addition of radiation, fan
coils, etc., as appropriate. For instance, use of
170''F average water temperature would reduce the
heating capacity by about 23% on the average. This
reduction would be excessive in most of the
buildings.