HVAC System: (1) Describe the components of the system or systems (AH, VAV, RTU, Chiller, cooling tower, piping, pumps, type of duct, etc.).

Direct Expansion Air Conditioning serves as the main system used for the HVAC system. This kind of system utilizes RVEC or refrigerant vapor expansion/compression cycle to allow for the direct cooling of the air supply to an occupied space. Because there are both the split systems and one package system for the DX units the parts are going to be different. The packaged systems contain all four pieces of the RVEC system (evaporator, condenser, compressor, expansion device along with some unit controls). This includes internal ducting and fans. The split systems contain fans and the evaporator within the building. The rest of the RVEC system components are placed outside of the building as separate units allowing greater flexibility.

A. The purpose of each component.

The system will boast a hot water heating coil, a DX cooling coil, as well as an integral energy wheel. The cooling capacity is at thirty tons and utilizes CO2 sensors plus a VFD to change the quantity of Exhaust Air as well as Outside Air, based on existing occupancy of the building. The ductwork which covers return, supply, exhaust, and outside air will be galvanized sheet metal will have external duct insulation as its main insulation. Along with each VAV terminal unit will be sound attenuators. The three HVAC systems are the following: one DX packaged unit (at east end of building, outside) and two DX split systems. Ventilation is important and the Mechanical Room will include ventilation (exhaust with 200 CFM capacity) and heat (1KW wall heater).

B. How the component works.

The heating and cooling coils warm and cool the air and the energy wheel transfers back the heat. VAV or Variable Air Volume can serve various purposes and can act as a heating, air conditioning, and/or ventilating system with a constant supply of airflow at variable temperatures. Sound attentuators act like duct silencers for HVAC systems. The galvanized sheet metal ducts offer easy fitting and flexibility so the flow of air is unencumbered.

C. How the components work together.

The air needed to cool down the spaces is directly chilled by the systems' refrigerant located in the cooling coil. Since the refrigerant directly cools the air (the same for heating coil) there is higher cooling efficiency. Refrigerant piping however, cannot always e carried large distances. That is why there is one unit in the first floor, one in the basement, and an external part applied to the east of the building.

(2) Discuss the controls of the system and who installs the controls.

The controls are part of the APR Control which is a capacity-control device modulating refrigeration/air conditioning capacity that matches fluctuations happening within the BTU quantity of an existing load. The unit reads the heat content the returning air within the system and then changes the pressure of the suction gas. The APR Control can sense variations via the evaporator coil and the enthalpy of retuning air. The kind of person that installs an APR Control is a refrigeration mechanic and takes around 4-6 hours.

(3) Discuss the process of the cooling cycle through the system.

Air passes over an indoor cooling coil, heating cold liquid refrigerant, transforming it into a warm gas/vapor. A copper tube then transfers the vapor to the compressor, compressing it and increasing pressure. The hotter vapor goes through another heat exchanger, which is called an outdoor condenser. The hot gas then transforms into a warm high pressure liquid. It goes through a liquid line or a smaller copper tube and then to a dryer/filter, before making its way to an expansion device, minimizing the high pressure liquid to a low pressure and cold liquid. Then finally, the cold liquid goes through an indoor cooling coil, repeating the cycle.

(4) Discuss the process of the heating cycle through the system.

The same process exists within the heating cycle as it does the cooling cycle with one exception. The heating cycle incorporates a special valve located in the refrigeration piping reversing the refrigeration cycle. In colder weather, a defrost period is necessary for a heat pump.

(5) Discuss the energy conservation measures, if any, for the building.

The DX systems offers flexibility and lower costs as well as lower maintenance. The packaged and split systems can be used for a variety of situations with high capacity. The lower costs come from lower maintenance which leads to energy conservation. Sealing and insulating the ductwork also saves energy and reduces leaks.

(6) Why was this system used as compared to another?

Because the DX systems are low maintenance compared to other system types and remain a reliable choice, suitable for the estimated usage, it is a cost-effective option that augments life-cycle expenses. The DX systems will contain two air cooled condensing units. One has the cooling capacity of twenty tons and will serve the first floor. For the basement level, the second unit will have half the capacity (ten tons). The units will be able to accommodate VAV applications and feature dual refrigerant circuits housing scroll compressors. The Carrier 38AUDB25 and the 38AUDB12 serve as the basis of the design. Since the first floor unit has an airflow of 8,000 CFM, the basement will have 4,000 CFM. The VAV terminal units have hot water reheat coils with all zones offered one.
(7) Discuss the impact of the HVAC system on the schedule.

Because it is using three total DX systems, it may take a little longer because the split systems mean having parts placed externally on the building and each floor. However, the installation may not take long with the control unit only taking at maximum 6 hours.

PLUMBING System:

(1) Potable water supply source, waste discharge point for sanitary and storm.

There will be two full-length trench drains and they replace the floor drains existing within the building. The new drains will be connected to existing underground waste lines. The trench drains are in the latrines. Drain lines will be in the mechanical room and the other in the cadre lunge for ice makers.

(2) Type and location of water pipes.

There are two types of water pipes: hot and cold water pipes. There is a firestop material covering the pipe as well as rock wool pipe insulation and sealant. There is a steel pipe sleeve. The water line size is 3" and is 2 1/2" where the main shut-off valve is. The water pipes run alongside the latrines and cadre lounge.

(3) Type and location of sanitary sewer pipes.

The sanitary sewer pipes will be located in four bathrooms or latrines (two male, one Coed and one female). Because there will be six floor-mounted flush valve toilets, three showers, eight wall-hung lavatories, and five wall-mounted flush valve urinals, the sanitary sewer pipes will be varied. Along with toilets, ten stainless steel sing-bowl classroom sinks, two hose bibbs, two dual level electric water coolers, and one floor-mounted mop sink will round the rest of the water usage.

(4) Discuss the pumps in the systems.

There is a domestic hot water recirculation pump, 11 GPM at 1ft, 115 volts 1.4 full load amps. There is also an in-line hot water circulating pump for maintenance of proper loop temperature at the water heater.

(5) Discuss any controls in the system.

There is one gas-fired water heater that through direct vent and an input of 125 MPH (capacity of 65 gallons) will heat up the water. The basis of the design is Lochinvar SNR126-065. The aforementioned pumps will also act as controls along with the valves. The mixing valves restrict the maximum temperature of hot water to 120F.

(6) Discuss the hot water source and distribution (re-circulation or non-re-circulation)

The hot water will come from the hot water heater and will recirculate due to the hot water recirculation pump.

(7) Discuss the impact of the plumbing system on the schedule.

The plumbing system is complex, involves including new trench drains, although it will contribute to the existing framework. However, there is a need to create several latrines and various functions for the water such as the water coolers. This may add more time to the schedule especially if any problems arise with the piping.

ELECTRICAL System:

(1) List service amperages and voltage to the MDP.

The MDP or Main Distribution Panel and electrical service will be provided at a rate of 480Y/277V, 4-wire, 3-phase and 208Y/120v transformers.

(2) List operating voltage(s).

The operating or service voltage is 400 amps.

(3) Describe the control systems.

One control system is the SMART meter and it is an electronic device, recording electric energy consumption of one hour or less intervals, communicating data at least daily to the utility got billing and continuous monitoring. A distribution board or breaker panel in other words, will divide electric power feeds into subsidiary circuits while also granting a circuit breaker/protective fuse for every circuit at no more than 100A at 208v-3ph. The transformer is also another kind of control system in that transfers electricity via two or more circuits.

(4) Describe the electrical from…