120 Unit High Rise Multifamily

General Description

A twenty story high rise apartment building located in New York, NY. This sample project is a 78,000 square foot building containing 120 apartments. The building was constructed in 1950 and contains the original 10,000,000 btu/hour oil-fired steam boiler. The building envelope consists of 8" block walls with 4" face brick, 4" concrete flat roof with no insulation, and single pane windows. Domestic hot water is produced by a separate 500,000 btu/hr oil-fired boiler with a 500 gallon storage tank. A blower door was not a viable technique to measure infiltration, instead the ACH (air changes per hour) was estimated and adjusted to match billing. The landlord pays all utility costs including oil for heat, hot water and all other electric costs. A utility bill analysis has been performed for both electric and #2 oil.

Both boilers are located in the basement level mechanical room. Each apartment contains a through-wall PTAC AC unit installed in the living area. The average AC unit is sized at 12,000 btu/hour. All AC units were installed in 1982 and are estimated to have an aggregated output capacity of 1,440,000 btu/ hour (average unit size * 120 units). Note: only ½ of each apartment is served by air conditioning (living area only). Window units are not permitted in bedrooms due to wiring and electrical load concerns.

The thermostat is set to 73F as the occupied heating temperature and not set back (since tenants do not pay for heat -thermostat was adjusted to match billing). The occupied cooling temperature is set to 71F with no setbacks (tenants do not pay their own cooling costs – adjusted to match billing).

Shared appliances include a 6 coin-op clothes washer with 4 matching coin-op electric dryers. These are located in the basement. Each apartment has an electric oven and range, and a refrigerator.

Improvements modeled include: a boiler replacement, new Energy Star refrigerators, new Energy Star rated washers and gas dryers, new AC units, targeted air sealing including window weather stripping, an additional 2" of rigid insulation under new roof, and lighting improvements.

Packages Included

"Measures with Payback of 10 years or less "- included measures with a simple payback of ten years or less. Includes: 86% efficient boiler with outdoor reset control, new Energy Star rated refrigerators and clothes washers, gas dryers, window weather strip instead of window replacement, replacement of all incandescent fixtures with 20 W fluorescent fixtures in apartments, and 2" of additional insulation in roof.

"Fast Payback Package" – Includes measures which enjoy a simple payback of 5 years or less. This includes new refrigerators, lighting, window weather stripping, washers, dryers and additional roof insulation.

"All Measures Package" – Contains all measures regardless of simple payback. Package included new boiler, appliances, lighting, roof insulation, new windows, and AC units.