HomeMy WebLinkAboutFile Documents.614 North St.0248.2017 (44).ARBK
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Bighorn Consulting Engineers, Inc.
569 South Westgate Drive, Suite 1, Grand Junction, CO 81505
Phone: 970-241-8709 Fax: 970-241-9514
614 W North, Aspen
Mechanical Design Narrative
September 14, 2017
This narrative is to provide permit information on the above residence. Full mechanical
design will follow to coordinate with architectural layout of the space.
General
The residence is approximately 4,000 ft2, two-story structure with a basement.
Energy Compliance
The walls, windows, roof, foundation, partitions, etc will meet the prescriptive
requirements of the IECC. Should this deviate from the prescriptive requirements, a
ResCheck document will be completed to show compliance.
A REMP check sheet will be submitted if necessary with regard to any snowmelt being
designed and required renewable energy on the residence.
Plumbing
Boilers will be installed in the residence for space heating and domestic water heating.
The boilers will be similar to the Lochinvar Knight, WHN models. The boilers will take
care of the heating in the fan coils, radiant floor heating, kitchen make up air for a hood
over 400 CFM and the domestic water load. The loads for those items are as follows:
FC’s (70,000 BTUH), Kitchen Hood MUA (75,000 BTUH), Radiant Floor (80,000 BTUH),
Domestic Hot Water (132,000 BTUH). If we use the boiler for all systems, we can take
credit for some of the systems not performing simultaneously. We can credit
approximately ½ of the domestic water load. The total boiler load output would be
291,000 BTUH. When you de-rate this for altitude (0.84) and efficiency (0.92) the input
for the boiler system needs to be approximately 375,000 BTUH. The project should plan
on installing (2) two boilers at WHN-200. These would give slightly more than the load
called for in the load calculations and would provide some redundancy in case one boiler
was being repaired. Condensate from the boiler system would need to go through a
neutralizer as it will be acidic.
Domestic hot water will be routed from the mechanical room on the lower level. The
water heaters will be sidearm water heaters similar to Lochinvar SIT-60 (2). The heating
fluid will come from the boiler system in the residence.
M. Blaine Buck
9-15-17
10/11/17
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Heating, ventilating and air-conditioning
The HVAC system in the residence will consist of the following. Fan Coils for cooling
and supplemental heating and radiant floor heating for 1st stage of heating.
The lower level will have radiant heating installed in the floors. No supplemental heat
would be required for this level. A 300 CFM heat recovery ventilator will be required for
this level to provide for ventilation. Ducts will be routed from the toilet rooms for exhaust
and supply to each room with a small 4” supply duct. Exhaust and outside air will be
taken in and/or exhausted through a wall vent.
The main level will have radiant heating and a fan coil installed. The fan coil will be
approximately 2,000 CFM and have a 4 ton condensing unit on the exterior of the
building for cooling. The fan coil will have 4 zones on the main level for separate control.
The fan coil shall be variable speed on a VFD so it does not require a bypass damper.
The radiant floor will be the 1st stage of heating. The fan coil shall have a heating water
coil installed to cover the outside make up air necessary for the kitchen hood as well as
enough load to make the air temperature from the fan coil reach 95 degrees in the
winter. The condensing unit shall be a minimum 16 SEER similar to the Lennox XC16.
The fan coil will be similar to the Lennox CBWMV model sized correctly for the coil and
CFM.
The upper level will have radiant heating and a fan coil installed. The fan coil will be
approximately 1,400 CFM and have a 3 ton condensing unit on the exterior of the
building for cooling. The fan coil will have 4 zones on the upper level for separate
control. The fan coil shall be variable speed on a VFD so it does not require a bypass
damper. The radiant floor will be the 1st stage of heating. The condensing unit shall be
a minimum 16 SEER similar to the Lennox XC16. The fan coil will be similar to the
Lennox CBWMV model sized correctly for the coil and CFM.
The in-floor radiant heating shall be piped at 10” on center piping at ½” in the floor. Each
zone and loop shall be routed to manifold boxes at select locations on each level.
The boiler system described above shall have pumps for each system for injection
pumping, different water temperatures and controls. The domestic water system shall
have a priority call when it is in need of boiler water, it will be first priority and will drive
the temperature of the heating water system.
Exhaust fans will be installed at all toilet room locations to provide code required exhaust
in those locations.
Grilles, Registers and diffusers will be floor and/or ceiling as required in the spaces. The
registers will be installed as near to the outside walls as possible. Linear grilles shall be
used in most locations.
END OF MECHANICAL NARRATIVE
10/11/17