OFFICE BUILDING COMFORT SOLUTIONS SERVICE PRO MAX 3.0™ STATE-OF-THE-ART PREVENTATIVE MAINTENANCE ANALYSIS TO CERTIFY THAT YOU ACHIEVE THE MAXIMUM COST SAVING EFICIENCY OF YOUR EXISITING HEATING & COOLING EQUIPMENT ALLOWS FACT-BASED REPAIR / REPLACE DECISION MAKING ANALYSIS DETAILED REPORTS TO PROVIDE MANAGERS ACCURATE REAL-TIME EFFICIENCY AND PERFORMANCE STATUS LEVELS OF YOUR EXISTING HEATING & COOLING EQUIPMENT PROVIDES PRE-TEST AND POST-REPAIR EFFICIENCY % INDEX VALUES OF EACH UNIT Standards based on: The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) & Air Conditioning Contractors of America (ACCA) Standards 180 ACCURATELY ESTIMATES THE HEATING & COOLING ACTUAL % CAPACITY OF EACH UNIT IF IT WAS SERVICED TO OPERATE LIKE NEW SUPPORTS SOUND BUSINESS DECISIONS DRIVES EFFICIENT EQUIPMENT BUDGETING ANALYSIS IMPROVES YOUR HEATING & COOLING SYSTEM’S OPERATIONAL AVAILABILITY & LIFECYCLE COST Tucson Electric Power (T.E.P.)

REBATE IS OFFERRED ON FOUR TON OR LARGER ROOF-TOP PACKAGE UNITS AGE OF EQUIPMENT: UNIT(s) MUST BE THREE YEARS OR OLDER TESTING & SERVICE MUST BE PERFORMED DURING THE A/C TUNE-UP (N/A @ HEAT TUNE-UP) T.E.P. REBATE IS OFFERED ONCE EVERY SIX YEARS ON EACH HVAC UNIT TESTED Examples of Program Cost: Larger Units Cost & Rebate Price % Discount: An industry leading approach to planned schedule maintenance programs Employ highly skilled professional team of service technicians – all certified Efficient preventative and diagnostic tasks reducing operating costs and decreasing energy consumption Comprehensive on-site inspection of your existing mechanical and environmental systems Contact us today at 520-629-9833 to request a meeting at your facility with one of our commercial accounts representative team members. The key objective is to offer and ensure a comfortable, healthy workplace and protecting the environment. Contact Hamstra at 520-629-9833 before noon and we 100% guarantee a service technician will be at your facility the same day before the close of our business hours.

Hamstra offers the exact same testing activities as the Premium Plus Plan. The following cleaning activities are omitted to provide an alternative lower-cost plan: Evaporative & condensing coils, blower wheels & condensate pans are excluded. By offering these activities separately, you select the requested cleaning per system. Name*Email*Phone*How May We Help You? Contact us today regarding a complimentary estimate Request a meeting at your facility with one of our commercial accounts representative team membersclicking in ac unitPower Knot treated a four ton (14 kW) roof-top packaged air conditioning unit with its Synthetic Refrigerant Additive (SRA) at the Mission Valley Elementary School in Fremont, California. average cost of a air conditioning unitAfter treatment, the efficiency of the unit increased by over 16%, resulting in savings in electricity cost and increasing the air conditioning cooling capacity for 32 students in their classroom. ac unit no longer cooling

However, the room did not get ice cold! [In the past, Power Knot referred to the product as the Synthetic Refrigerant Catalyst; the term Additive is now preferred.] Mission Valley Elementary, one of 28 elementary schools within the Fremont Unified School District (FUSD) is located on the southeast side of San Francisco Bay in the beautiful city of Fremont which lies between San Jose and Oakland in Alameda County. The school’s population is over 750 students with class sizes of 1:20 in grades K-3 and 1:30 in grades 4-6. The school consists of a rich ethnic diversity of students. With a shrinking budget in the fiscal year 2010, the Fremont Unified School District is exploring various ways to reduce expenditures. Energy cost is one of the major expenses for the 48 schools in the Fremont district. Attendance in the Fremont schools has been increasing for the past few years. This has driven up the cost for operating the schools from salaries and classroom supplies all the way to facilities and maintenance.

The energy cost for classroom electricity and heating has also increased significantly over the years. FUSD is interested in deploying new energy saving solutions to help them reduce their energy cost. The SRA from Power Knot improves energy efficiency of a cooling system and can saves customer’s money. It is injected into the refrigeration circuit of the cooling system and improves heat transfer by eliminating the “oil fouling” that occurs in a cooling system. Power Knot guarantees a minimum of 10% gain in efficiency after the proper application of the SRA. In the case of FUSD, this can translate to greater cooling in the classroom with the same amount or a decrease in electricity usage. The packaged air conditioning unit is located on the roof of the classroom. Each classroom is cooled by one such air conditioning unit. There are four roof-top AC units per building. Each AC unit has an economizer feature to allow outside fresh air to enter into the classroom. The unit is shown in figure 1;

details of the unit are listed in figure 2. This unit uses about 7.2 kW to operate. It runs about for about eight hours a day 110 days a year. With electricity cost at 17¢ per kWh, that amounts to an annual cost to operate of over $1075. To measure the gains in efficiency, Power Knot used the method of measuring enthalpy. The enthalpy method entails measuring the wet bulb temperature of a direct exchange air conditioning system before and after the treatment of the SRA. As the air is heated or cooled, the a/c unit is heating or cooling the gases (sensible heat) and the water vapor (latent heat). The cooling process often removes water vapor from the air. Hence it is why we measure the wet bulb temperatures to include the moisture factor of calculating the energy required to cool the water in the air. At the Mission Valley Elementary School, we measured the wet bulb temperature on the roof-top AC unit in the air flow compartment area before and after the evaporator.

From the wet bulb temperature we can calculate the enthalpy. The work done by an air conditioning unit is proportional to the difference in enthalpy between the supply air hS and hR return air: This proportionality is assured because the rate of flow of air through the space is constant, regardless of the output of the air conditioner. By treating this air conditioning system with the SRA, we will measure the heat absorption before treatment (hB) and heat absorption after treatment (hA). If the flow of air remains constant before and after treatment (and that is a very reasonable assumption), the gain in efficiency is calculated as: The enthalpy can be calculated at a specific time based on the wet bulb temperatures. This calculation of enthalpy is made using spot readings of the wet bulb temperatures. We measured the wet bulb temperatures using an Amprobe Model TMD-10 – Dual Thermometer. We installed the SRA into the low pressure port of the system using a hand pump as shown in figure 4.

The installation is performed while the system is running. This ensures the liquid cannot slug the compressor. It also results in no disturbance to the occupants of the space being cooled. The installation takes only minutes and was completed at 13:45 on 2010-10-12. We measured the enthalpy 15 minutes before that and 45 minutes after that. We allowed 45 minutes for the SRA to take effect. On a small system like this, we would like to leave it at least an hour, but it was getting too close to the end of the school day to wait any longer. The figures we measured for wet bulb temperature for the system before and after treatment are shown in figure 5. The table also shows the calculated enthalpy. As can be seen, in about 45 minutes after treatment with the SRA, we measured a greater delta temperature across the evaporator as compared to the delta temperature before the treatment. This means the air conditioning system is running more efficient and increased cooling capacity for the students in the classroom: