hvac due diligence report – salem public library – 370

HVAC DUE DILIGENCE REPORT – SALEM PUBLIC LIBRARY –370 ESSEX STREET – SALEM, MA Submitted to: CITY OF SALEM February 10, 2017 Submitted by: RDK ENGINEERS

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TABLE OF CONTENTS

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SECTION 1 Introduction

SECTION 2 Executive Summary

SECTION 3 HVAC Existing Conditions and Recommendations

SECTION 4 HVAC Existing Equipment Capacities Replacement Summary


INTRODUCTION

Salem Library 370 Essex Street Salem, MA Due Diligence Report Page 1 Job No. 20160681.00

1.0 INTRODUCTION RDK Engineers (RDK) was retained by the City of Salem to visit the Salem Library located at 370 Essex Street in Salem, Massachusetts to review the existing HVAC systems serving the property, with a focus on evaluating the systems. RDK visited the property on January 23, 2017. During the visit, RDK’s engineering review utilized the design plans provided from 1989 and toured the property with the current building manager. The building has been home to the Salem Library since 1889, starting life as a private residence. Major renovations occurred between 1979 and 1990. The RDK project team is as follows: Principal in Charge: Robert Persechini Project Manager: Bill Punch HVAC Department Head: Vincent Bettano, P.E. HVAC Engineer: Steve Rosen


EXECUTIVE SUMMARY


2.0 EXECUTIVE SUMMARY The building heating plant is in good condition with a new boiler installed in 2010. However, the hot water distribution in certain areas has been non-existent for many years due to reported leaks. All the air supply systems are twenty-seven (27) years old and are in various states of disrepair. This is expected since all the systems are past their normal life expectancy. There is no BMS (Building Management System) and the over thirty (30) thermostats are not labeled to indicate their function, causing confusion for both occupants and facilities personnel. RDK was informed that there are many occupant comfort complaints. The Children’s area requires electric space heaters to temper the cold air because the heating hot water system is not usable due to leaks in that area. This is not the best environment for children and a complete rehab of the hot water system including pressure testing; flow testing of the piping should be initiated to rectify the heating systems. Many of the air-handling systems require either extensive repairs or replacement. The existing air systems should be balanced to verify system performance. Review the requirements indicated in this report to determine the cost of repairs versus replacing systems in kind. Create a plan that allows for either replacing or redesigning cooling and heating systems to allow temperature control by either users or a facility BMS, which utilizes more energy efficient equipment. After updates are complete, it would be recommended that a maintenance contractor be engaged to change out filters on a regular basis and monitor performance at the maintenance periods established.


HVAC EXISTING CONDITIONS AND RECOMMENDATIONS


3.0 HVAC EXISTING CONDITIONS AND RECOMMENDATIONS RDK observed the mechanical systems in the Library. In the Ground Floor Mechanical Rooms, the gas-fired boiler installed in 2010 is a Weil-McLain model 88 Series 2 with a WJ500-15 burner producing 1,700 MBH of heat. Water is pumped via two (2) three (3) HP pumps (run/standby) operating at 208V. A 50-gallon domestic hot water tank, Ruud model PROG 50 was installed in 2015. Both the DHW heater and boiler are vented with flues (8” and 3”) thru the building. There are two (2) ceiling mounted recessed hot water unit heaters located in the area, locally controlled, and an air intake in the Boiler Room. The boiler room exhaust fan is not working and is wrapped to prevent cold air circulating because the fan has no back draft damper. The local controls are Metasys by Johnson Controls installed in 1987. The newer thermostats (local) are as manufactured by Honeywell. A second exhaust fan that was designed to exhaust air from the Children’s area was not accessible and at the time of the visit the UPS was non-operational. The design indicates this fan to be a two-speed fan capable of either 1,500 or 3,000 CFM. The AHU (SA-1), because of leaks, has no working hot water coil, delivering air to the Children’s area. The three (3) designed fire dampers were not present in the ductwork leaving the mechanical room. This should be rectified after being reviewed by a code consultant. The associated Air-Cooled Condensing (ACC) unit as manufactured by Snyder is located outside on grade and is non-operational. The air distribution ductwork is partially exposed in the Children’s area and is not insulated. Should this area be architecturally modified it would be energy efficient to insulate the ductwork. The Ground Floor AHU is in a very confined crawl space. This unit serves the Front Lobby. It is a Carrier unit, Model 39 LB103. At the time of the visit, the UPS was non-operational. The Ground Floor bathrooms are each exhausted with a ceiling mounted exhaust fan controlled by a light switch, which appear to be in good working order. The exhaust air is ducted to a common exhaust louver. There is a working wall mounted hot water cabinet unit heater located at one of the Ground Floor entry doors. The main double doors utilize the two (2) ceiling mounted ducted hot water cabinet unit heaters, both of which were non-operational, at the time of the visit.


The perimeter radiation heating utilizes various fin tube profiles from sheet metal baseboard to low profile cast iron types. RDK was informed that the heating is non-operational due to reported leaks in the piping loops. The First Floor AHU unit serves the Reading Room. It is a Carrier unit, Model 40QBS 060. The associated air-cooled condensing unit was reportedly replaced last year. RDK was informed that the unit was not meeting the cooling requirements. The outdoor air damper is non-operational and should be replaced now. A second First Floor AHU unit serves the Book Stack area. It is a Carrier unit, Model 40AQ036310BU. The associated air-cooled condensing unit is indicated as Unit # 6018. It was not possible to see if the outdoor airflow is regulated. The tight confines of this vertical unit has a short section of both return and supply uninsulated ductwork to a shelf area that hold both a vertical discharge air grille on the top of the shelf and a linear return grille at the floor level of the same shelf. This results in poor air distribution and a lack of air movement. It is recommended to modify the air distribution in conjunction with future architectural modifications. The three (3) First Floor bathrooms are each exhausted with a ceiling mounted exhaust fan controlled by a light switch, which all appear to be in good working order. The air is ducted to a common exhaust louver from the Break Room bathroom, one (1) public bathroom (unisex), and directly to an outdoor louver from the second public bathroom (all gender). There are two (2) working floor mounted hot water cabinet unit heaters located at the main First Floor entry doors controlled by a local thermostat. The thermostatically controlled perimeter radiation utilizes both wall mounted individual radiators (located between rows of stacks) and a continuous perimeter fin tube behind bookshelves. The bookshelves are raised up and the support has a continuous frill to allow return air back to the radiation. The Mezzanine Floor AHU is in a very confined crawl space. This unit serves the Break Room and the Book Stacks. It is a Carrier unit, Model 40QHS 060. The unit was non-operational at the time of the visit. Repairs to this unit would appear to be difficult due to the space constraints. The replacement of this unit with a new unit better configured to the space may not be cost prohibitive as compared to the cost of repairs to this unit. The Break Room perimeter radiation-heating baseboard is operational. The thermostatically controlled perimeter radiation in the Book Stacks utilizes both wall-mounted individual radiators (located between rows of stacks) and a continuous perimeter fin tube behind bookshelves. The bookshelves are raised up and the support has a continuous frill to allow return air back to the radiation.


A second Mezzanine Floor AHU unit serves the Book Stack area. It is a Carrier unit, Model 40AQ036310BU. The associated ACC unit is indicated as Unit # 6643. It was not possible to see if the outdoor airflow is regulated. The tight confines of this vertical unit has a short section of both return and supply uninsulated ductwork to a shelf area that hold both a vertical discharge air grille on the top of the shelf and a linear return grille at the floor level of the same shelf. This results in poor air distribution and a lack of air movement. It is recommended to modify the air distribution in conjunction with future architectural modifications. The Second Floor is served by AHUs located in the Attic and a rooftop unit (RTU). The air distribution is thru concealed ductwork located in soffits with sidewall air supply grilles. Perimeter radiation is located at the windows (with a few windows not having any heating) utilizing a linear grille at the top of the shelving under the windowsills. The AHUs are as manufactured by Carrier. The Reference area is supplied by a Model 39LB0606187 unit. The Business Office area is supplied by a Model 39LB03606102 unit. A separate air-handling unit that is also located in the Attic with ductwork serving the spaces, which is a Carrier Model 39LA0306101 unit, serves the occupied Third Floor. It would be recommended to replace this equipment with updated 3-ton and 5-ton capacity new equipment due to the equipment no longer achieving design conditions for cooling as reported “partial cooling”. The RTU that serves the Second Floor was non-operational at the time of the visit. It used to utilize an electric heating coil. The Carrier Weathermaker unit should be replaced with an equivalent 90MBH total cooling new unit. It would be recommended to utilize a more efficient gas heating section in the new RTU. In addition to the condensing units described that are located on grade, the remaining six (6) split system condensing units are located on the roof with exposed refrigerant lines running along the roof. It would be recommended to replace these units along with the associated AHUs. Although various manufacturers presently manufacture the condensing units, it would be recommended to select one (1) manufacturer. The six (6) condensing units installed now are:

Payne: Model PA13PR036 Payne: Model PA13PR036

Thermal Zone: Model TZAA-360-CA757 Thermal Zone: Model TZAA-360-CA757

Allegiance: Model 2A7C0036 American Standard: Model TTA091A300GA

There were no reported problems with the third floor exhaust fan located in the Attic, a Peerless Model 9. It would be recommended all air systems be balance to achieve the design air flows intended.


Condensing Units Children’s Library Condensing Unit Refrigerant Piping Entering Building

Boiler and DHW Flues Hot Water Circulating Pumps Boiler

Hot Water Unit Heater Boiler Room Ventilation Fan Basement Air Handling Unit


Non-insulated Partially Exposed Ductwork Children’s Library Air Supply Ductwork

Cast iron Radiation Perimeter Radiation Exposed Ductwork

Exposed Ductwork Boiler Room Ventilation Hot Water Heater


Wired Thermostat Exposed Radiator Electric Space Heater

Exposed Radiator AC Unit Supply and Return Grilles AC Unit in Closet Ductwork

AC Unit in Closet AC Unit in Closet Break Room Radiator Heating


Fire AC Unit in Closet Perimeter Sill Heating Refrigerant Piping on Roof

Condensing Units on Roof Inoperable RTU RTU Ductwork on Roof

Condensing Units on Roof Hot Water Unit Heater in Attic AC Unit in Attic


Crushed Ductwork in Attic Hot Water Unit Heater in Attic

Rusted Sheet Metal Louvers Perimeter Heating Blocked by Shelving

Deficiencies/Code Items

1. There are no volume dampers on the outdoor air intake ducts to the various systems to determine the amount of outdoor air supplying the various AHUs. It would be recommended the outdoor air volumes be updated to accommodate the latest design standards.

2. RTU-1, SA-1, SA-3, and SA-6 are all over 2,000 CFM capacity and require smoke detectors in the return air ductwork. It does not appear that any have been installed.


HVAC EXISTING EQUIPMENT CAPACITIES REPLACEMENT SUMMARY


4.0 HVAC EXISTING EQUIPMENT CAPACITIES REPLACEMENT SUMMARY Children’s Library 1. Replace SA-1 with equal – 5,200 CFM @ 1.75”wg, 183 MBH cooling, heating coil 60-85F, 14 GPM

@ 500 FPM. Provide smoke detector in the return air.

2. Replace associated air-cooled condensing unit.

3. Replace associated exhaust fan, 1,500/3,000 CFM, ½ HP, 208/3/60. Front Lobby 1. Replace SA-2, Carrier unit, Model 39 LB103 with equal – 1,600 CFM @ 1.5”wg, 65.9 MBH

cooling, heating coil 60-85F, 5 GPM @ 500 FPM.

2. Replace associated air-cooled condensing unit. Ground Floor 1. Replace hot water cabinet unit heaters (2) – 600 CFM, 31,800 BTUH, 120/1/60. First Floor Reading Area 1. Replace Carrier unit, Model 40QBS 060 with equal – 2,000 CFM @ 0.75”wg, 58 MBH cooling.

2. Replace associated air-cooled condensing unit.

3. Replace non-operational outdoor air damper. First Floor Book Stack Area 1. Replace Carrier unit, Model 40AQ036310BU with equal – 1,200 CFM @ 0.65”wg, 43.8 MBH

cooling.

2. Replace associated air-cooled condensing Unit #6018. Mezzanine Floor Book Stack Area 1. Replace Carrier unit, Model 40AQ036310BU with equal – 1,200 CFM @ 0.65”wg, 43.8 MBH

cooling.

2. Replace associated air-cooled condensing Unit #6643.


Mezzanine Floor Break Room 1. Replace Carrier unit, Model 40QBS 060 with equal – 2,000 CFM @ 0.75”wg, 58 MBH cooling.

2. Replace associated air-cooled condensing unit. Second Floor Book Stack Area 1. Replace Carrier unit, Model 39LB0606187 with equal – 2,500 CFM @ 1.5”wg, 84 MBH cooling

2. Replace associated air-cooled condensing unit. Provide smoke detector in return air. Second Floor Business Office Area 1. Replace Carrier unit, Model 39LB03606102 with equal – 1,500 CFM @ 1.5”wg, 58 MBH cooling,

heating coil 65-85F, 3 GPM @ 500 FPM.

2. Replace associated air-cooled condensing unit. Second Floor Reference Area 1. Replace Carrier roof top unit (RTU), Model Weathermaker with equal – 3,100 CFM @ 0.6”wg,

90.6 MBH cooling total capacity, 69.3 sensible cooling capacity, electric heating coil 15.8KW, 208/3/60 or replace electric heating coil with gas-fired section, 53.9 MBH. Provide smoke detector in return air.

Third Floor 1. Replace Carrier unit, Model 39LA0306101 with equal – 2,240 CFM @ 1.5”wg, 65.9 MBH cooling,

heating coil 65-95F, 4 GPM @ 500 FPM. Provide smoke detector in return air.

2. Replace associated air-cooled condensing unit. General 1. Pressure test all perimeter radiation heating piping and all duct hot water heating coils piping

and repair all leaks in the piping loops.

2. Air and water balance all new systems.

3. Replace all integral thermostatically controlled valves with new control valves with remote thermostats.

4. Identify all thermostat zones and verify operation.


5. Clean all ductwork.

6. Insulate all uninsulated hot water piping and ductwork.

7. Verify operation of all automatic control dampers for all outside air intakes and exhaust to outdoors.

8. Provide new automatic control dampers on outside air intakes and exhausts where nonexistent.

hvac due diligence report – salem public library – 370

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