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What size comfort system do I need for a home or building that’s X,XXX square feet?

Despite popular belief, the square footage per ton “rule-of-thumb” is a horribly inaccurate method of sizing comfort equipment. The only way to determine the correct system sizing for your home is to calculate the heat gain/loss in BTUs using ACCA Manual J or ASHRAE load calculations. If you consider two different buildings (each 2,000 square feet) – one built in the 1960’s with poor construction quality and the other built to modern code requirements – the square footage per ton method would assume that both homes require the same size system. This is absolutely not the case! Manual J & ASHRAE load calculations consider a number of factors including construction quality, insulation R-values, door and window sizes and types, internal occupants and appliance heat gain, building orientation, etc.

What are Manual J, Manual S, and Manual D load calculations and why are they important?

Manual J load calculations determine the heat gain/loss of your home in BTUs. Manual S calculations verify proper equipment sizing in conjunction with the Manual J load requirements. Manual D duct calculations are used to size ductwork system trunks and branches to achieve proper airflow and velocity to each room in your home. Each of these calculations are imperative for comfort system sizing, design, and installation.

I’m building an addition to a home or building. Can I just add new ductwork from my existing system?

If your existing comfort and ductwork systems are properly sized, in most cases adding on additional ductwork and air devices will not provide adequate comfort for the addition or the existing building area. Another consideration when adding onto a home or office is that newer additions made to older construction will feature drastically different construction materials, so having a single comfort system that conditions both areas can result in notable temperature differences between the two types of construction - even if the comfort equipment and ductwork are properly sized.

I’m making changes to the construction after plan approval. Do I need to update the mechanical?

Absolutely. Any construction changes relating to materials, insulation, doors/windows, skylights, internal heat gains, building orientation, etc. can have a notable impact on the amount of capacity and air delivery required to each room/area. Make sure you consult with the mechanical designer and have the mechanical load calculations and design updated accordingly.

How large should I make the mechanical rooms/closets?

Equipment clearances for code requirements and service access vary depending on the type and capacity of the HVAC equipment to be installed. In general, the minimum size of a mechanical closet for a gas furnace must be 56” wide by 39” deep. These dimensions would account for the furnace and necessary ductwork, but additional area would be required for any necessary combustion ducting and flue venting (which can vary in size based upon the number of fuel burning appliances in the mechanical area).

How much attic clearance do I need for ductwork systems?

This will vary based upon the volume of air being moved to each location, building layout, and whether or not duct intersections are required to achieve proper supply and return air movement. The general rule of thumb for required attic space is the height of the ductwork plus 18-20” for insulation and truss members. Keep in mind that the mechanical ductwork cannot impede the insulation line.

Is it better to have insulation installed directly above the ceiling or at the bottom of the roof deck?

Creating an encapsulated attic (with insulation installed above the ductwork) will result in a much more energy-efficient home and allow for a smaller HVAC system to be utilized. When ductwork systems are installed above insulation (outside of the thermal envelope), larger HVAC systems must be installed to account for the additional heat gain placed on the ductwork.

Does the specific orientation of the home or building affect the mechanical load?

Absolutely! Two identical homes or buildings can have drastically different cooling loads if they are oriented differently. Buildings with extensive south/west facing glass will have a much higher load than buildings with mostly north/east facing fenestrations.

What is fresh air ventilation? Is it required?

Mechanical code requires the introduction of fresh air ventilation for both new residential homes and commercial buildings. The specific volume of fresh air required varies based upon square footage, number of rooms, occupancy, and building use. The heat gain from the associated fresh air introduced must be accounted for in the load calculations and equipment sizing.

What are transfers and how do they differ from ducted returns?

Mechanical code requires that all rooms with doors receiving more than 100 CFM of supply air delivery contain either ducted returns or transfers (excluding bathrooms, laundry rooms, and kitchens). It is not always possible to locate ducted returns in each room, so a transfer (either ducted or wall grille) creates a path between an isolated room and the main system return grille to allow return to be drawn back to the system.

Do multi-level homes / buildings require separate systems for each level?

Ideally, yes. Because heat rises, multi-level buildings with single systems that condition area on multiple levels are not able to maintain even temperatures on each level. The best practice includes having separate HVAC systems for each level. If this is not possible, at a bare minimum, zone damper/control systems should be installed to allow airflow delivery control to each level independently. Keep in mind that zone and bypass dampers must be fully accessible for service and replacement after installation.

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When should I schedule the mechanical work in relation to other trades?

If any underground mechanical installation is required (such as underground duct systems or line-set chases), this must be scheduled well in advance of having foundations poured. When it comes time to schedule the rough-in phase, the mechanical contractor should be the very first trade on-site. Duct systems are much larger than other utilities and the specific locations are much more imperative. If the electricians and plumbers complete their rough-in phase installations prior to the mechanical, there are often location conflicts that require items already installed to be relocated.

What items need to be completed / constructed in order to start the mechanical rough-in phase?

The home or building will be ready for the rough-in phase after framing has been completed, and the mechanical rough-in phase should be completed prior to electric, plumbing, security system, central vacuum, roof, or insulation work to avoid construction conflicts and additional fees.

What items need to be completed / constructed in order to start the mechanical completion phase?

The home or building will be ready for the mechanical completion phase after interior/exterior painting is completed, electrical disconnects are installed, and gas/drain piping is in place. Keep in mind that electrical and gas service must be active to the location in order to perform the HVAC equipment start-up and commissioning process.

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What is two-stage cooling / heating and what are the benefits?

Two-stage cooling/heating comfort systems provide additional levels of system capacity. The first stage (often around 70% of total capacity) is used during mild weather conditions and consumes less electricity or gas than single stage systems running at 100% continuously. During extremely warm or cold periods (or when the thermostat set-point is adjusted more than 3 degrees at once), the second stage of cooling/heating is engaged to provide 100% capacity delivery as needed. The main benefit of two-stage comfort is notable annual energy savings compared to single-stage equipment.

What are variable-capacity compressor systems and what are the benefits?

Variable-capacity compressor systems feature hundreds of stages (capacity levels) that allow the systems to modulate compressor speed up and down to deliver only the amount of cooling or heating capacity actually needed in the home or building. The main benefit of these systems is a notable reduction in utility costs compared to systems that constantly operate at 100% capacity.

What’s the difference between fixed-speed PSC / constant-torque / variable-speed indoor fans?

Fixed-speed PSC fans operate on single speeds for cooling/heating modes and have been commonly installed in comfort systems for the past few decades. This type of motor is being phased out in most newer comfort systems due to new energy efficiency regulations. Constant-torque motors are ECM (Electronically Commutated Motors) with multiple speed taps that are designed to maintain constant torque levels while in operation. These motors offer improved energy efficiency compared to older style fixed-speed PSC fans. Variable-speed indoor fans are also ECM type motors but are designed to maintain a constant CFM (cubic feet per minute). Variable-speed fans are the most energy-efficient and allow a great deal of versatility with airflow adjustments. As opposed to other types of fans that basically operate with On/Off functionality, variable-speed fans slowly ramp up-to and down-from maximum speed which results in quieter operation and less noticeable airflow noise inside the home or building.

What is a ton rating and what does it mean?

Tonnage ratings refer to the nominal capacity (size) of a comfort system. One ton of capacity equates to 12,000 BTU. Tonnage is somewhat of a loose rating when it comes to true system capacity, because the actual delivered capacity varies among different climate zone, manufacturers, product types, and system efficiency levels. In short, systems with the same tonnage from two different manufacturers can have notably different sensible capacity delivery.

What are SEER / EER ratings and what do they mean?

SEER stands for Seasonal Energy Efficiency Ratio and EER stands for Energy Efficiency Rating. Think of SEER and EER like miles per gallon for the cooling system. The higher the SEER / EER, the more energy efficient the cooling system and the less it will cost to cool the home or building annually.

What are AFUE ratings and what do they mean?

AFUE stands for Annual Fuel Utilization Efficiency and is a rating for gas fired heating equipment. Think of AFUE like miles per gallon for the heating system. The higher the AFUE, the more of each dollar spent on natural gas (or propane) is used to actually generate heat that’s delivered to the home or building. In our warm Southern Arizona climate, higher AFUE gas heating equipment is not nearly as common as in colder climate areas due to the increased installation cost with long payback periods.

What are HSPF ratings and what do they mean?

HSPF stands for Heating Seasonal Performance Factor and is a rating for heat pump equipment. Think of HSPF like miles per gallon for the heating system. The higher the HSPF, the more energy efficient the heating system and the less it will cost to heat the home or building annually.

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My system isn’t cooling/heating. What can I check before I call for service?

Verify that your thermostat is set to the proper mode (cooling/heating) and the temperature set-point is below (cooling) or above (heating) the current indoor temperature. If you’re handy, you can also check for tripped circuit breakers or blown fuses. Older / weak circuit breakers can trip from time to time, but if the breaker trips repeatedly after being reset, this can indicate an issue with the electrical circuit or your comfort system. If you find a blown fuse, odds are the root cause is something other than the fuse itself. If replacing the fuse gets your system back online, we still recommend having a professional evaluate your system.

How do I operate my thermostat?

If you have recently moved into a new office (or lost your thermostat user manual), don’t worry! The vast majority of thermostat user manuals are available online without special login access. Simply find the model number of your thermostat (typically located on the base plate or rear of the thermostat) and perform a Google search with the model number and words “user manual” – Example: “Nest T3008US user manual.”

What temperature set-points should I use for my cooling/heating?

Different people are comfortable at different indoor temperatures so we recommend keeping your thermostat set to temperatures that keep you and your clients the most comfortable. If your business receives excessive traffic with doors opening and closing frequently throughout the day, you may have to adjust your thermostat setpoint to compensate for the additional heat gain/loss. Keep in mind that the lower you keep your thermostat set in the summer (and the higher you keep it set in the winter), the higher your utility bills will be.

Should I turn my thermostat off or drastically change the set-point while my office is unoccupied?

There is a common misconception that turning your thermostat completely off or raising/lowering the temperature 8-10 degrees while your office is unoccupied will result in energy savings. This is actually not the case! Especially during the summer, when the indoor temperature and humidity increase well beyond comfort levels, your system will work extremely hard to return the building to occupied comfort conditions. The best practice is to set your temperature back no more than 3-5 degrees because setting back further will result in higher utility costs.

Should I set my indoor fan to Auto, On, or Circulate?

The best indoor fan setting for your needs can vary based upon your personal comfort, type of system, and the layout of your office. The “Auto” indoor fan setting operates your comfort system’s indoor fan only when the system is cooling or heating. The “On” fan setting will run your indoor fan continuously regardless of cooling/heating operation to constantly circulate air throughout your building. If your thermostat has a “Circulate” fan feature, using this setting will operate the indoor fan for a few minutes each hour just to circulate some air and prevent stagnant indoor air on mild days when there is no demand for cooling or heating operation.

Should I replace my old thermostat with a programmable thermostat?

Aside from being a mechanical code requirement for new system installations, switching to a programmable thermostat can result in notable energy savings. Most models feature time period functionality so you can program your temperature set-points for multiple time blocks each day. Going a step further, the Nest Professional thermostats we offer are also WiFi compatible so you can make temperature adjustments using your computer, tablet, or smart phone when you’re away from your office.

How often should I clean / replace my system’s air filter(s)?

Air filters will load (become dirty) at various rates depending on how often the indoor fan operates, how dusty the indoor air is, frequency that exterior doors open/close, etc. The best rule of thumb is to inspect your air filter(s) at least monthly and clean/replace them as necessary. Beware of filters that claim to be “90-Day Filters” because there is simply no way to guarantee that an air filter can be left in place for a 3-month period without becoming dirty and restricting system airflow.

Why does my thermostat say “Check Filter” when I just replaced it?

Thermostat filter reminders are typically set to display after a certain number of days or period of system operation. Your thermostat does not actually monitor the condition or cleanliness of your filters or know when you clean/replace them, so this reminder must be reset.

Do I need to have annual maintenance performed on my comfort system?

Absolutely! In most offices, the comfort systems are among the highest priced pieces of equipment installed, and you should protect your investment. Having proper annual maintenance performed will maximize energy efficiency (keep utility bills low), prevent system breakdowns, prolong the operation life, and maintain your system’s factory warranty coverage.

What system maintenance items can I perform myself?

We recommend keeping filters clean/replaced regularly, keeping plants and debris away from your outdoor units, and leaving the rest to us! HVAC equipment contains advanced electronics and is connected to utilities such as natural gas and high-voltage electricity. Taking safety considerations and factory warranty coverage into account, we do not recommend opening any service panels or attempting any repairs unless you’re a factory trained professional.

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What type of air filter(s) should I be using?

For most applications, we recommend a loose pleat type air filter with a MERV Rating of 8-11. If allergies or excessive indoor dust are of concern, we do offer solutions for high-efficiency indoor filtration and air purification. Care should be taken when considering the use of air filters with a MERV rating above 11 or electronic air cleaners. High efficiency air filtration products are often more restrictive than standard air filters, so care must be taken to ensure that your ductwork system can handle the increased static pressure without causing any damage to your comfort system.

I need better indoor air filtration! What can I do?

If standard air filters aren’t cutting it for you, don’t worry - we can help! The first step to impeccably clean indoor air is to ensure that your ductwork system is tight (leak free). We also offer a wide variety of indoor air quality products such as air cleaners and even air purification.

My comfort system circulates odors from the break room, copier room, etc. What can I do?

We have a solution for that! Ask us about indoor air purification using Air Scrubber Plus technology.

How often should I have my ducts cleaned?

In most offices with regular air filter cleaning/replacement, duct cleaning is necessary approximately every 10 years. If air filter maintenance is neglected or your duct system has leaks, sediment can accumulate within the duct system more frequently.

Is there any way to seal up leaky ductwork without replacing it?

Absolutely. Our patented Aeroseal process enables us to seal duct systems from the inside without having to replace duct or cut drywall to seal duct externally. Ask us for details!

How can I tell if my ductwork system has leaks?

Some indicators to watch for include excessive indoor dust levels, dirt trails at supply register openings, and cold air movement in attics/cavities where duct is present during cooling operation. If you think your duct system is leaky but aren’t positive, we can perform a duct blaster test and tell you exactly how much leakage is present.

Can I save money by having my leaky ductwork sealed?

Aside from the associated health and indoor air quality benefits, having leaky duct systems sealed can also save you quite a bit of money! The U.S. Department of Energy reports the typical office may lose from 20 to 30% of its conditioned air due to leaky ducts. As a result, your comfort system works harder and longer, consumes much more energy, and wears out sooner. The more leaky the duct system, the more savings to be had, but we have seen annual energy savings as high as 30% after performing our patented Aeroseal duct sealing process!

Is it okay to close off supply registers in rooms that are unoccupied?

To attempt to save money on utility costs, many building occupants tend to close off supply registers in rooms/offices that are rarely occupied. In most applications, we don’t recommend closing off more than 1 supply air register per system. Your comfort equipment and ductwork systems are designed and balanced to move a specific volume or air to each space in your building. Closing off or covering multiple registers will not result in any energy savings and will actually increase the static pressure in your duct system and potentially cause damage to your comfort system.

Is it okay to place furniture in front of return grilles?

System return grilles should not be partially or completely blocked by furniture, wall coverings, etc. under any circumstance. Restricting proper return airflow to your comfort system will reduce energy efficiency, system performance, and can cause damage to expensive system components.

Why does my furnace produce an odor at the beginning of each heating system?

The annual furnace odor is common and a result of dust accumulating on the heat exchanger over the months of inactivity. The high temperature of the heat exchanger burns the dust off over the first few heating cycles, and this odor should dissipate within 24-48 hours under normal circumstances. If you notice a smell that appears to be more “burning” or “electrical” in nature, turn your system off and contact us immediately!

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Does my comfort system need surge protection?

Most business owners invest in surge protection for their electronics, computers and copiers, but neglect to protect some of the most expensive equipment in their offices – the cooling and heating systems! Comfort systems contain many expensive electrical components such as compressors, fan motors, and control modules, and manufacturer warranties do not cover part failure resulting from power surges. The Intermatic AG3000 surge arrestors we offer provide industry-leading protection against both major surges and spikes (lightning, brownouts, utility spikes) and micro surges.

I have a whole-building surge protector installed, so my HVAC equipment is safe, right?

Not necessarily! While “whole-building” surge protectors installed at your main electrical panel provide protection against major surges and spikes from everything outside your meter, the average office in the U.S. experiences hundreds of yearly micro surges within the building’s electrical service. Large appliances such as refrigerators, motors, manufacturing equipment, hand dryers, and even comfort systems create micro surges within your electrical system when starting/stopping. While these surges typically do not result in immediate system failure, over time they degrade the integrity of electrical components and can result in premature electrical component failure.

What is condensate overflow protection and why do I need it?

As your cooling system removes heat from the indoor air, condensation is produced and drained from the indoor coil – as much as 5-15 gallons per day during high-humidity months! If your drain line becomes plugged with sediment or insects, all of this water is still going to drain somewhere. Condensate overflow conditions can quickly result in thousands of dollars in damage to walls, ceilings, and flooring and result in microbial growth if left unnoticed. The AquaGuard condensate safety overflow devices we offer detect overflow conditions and lock-out system operation to prevent your cooling system from creating additional condensation until the drain issue is corrected.

Is there anything I can do to prevent my indoor coil from rusting/corroding prematurely?

While there’s unfortunately no way to entirely prevent indoor coil corrosion over time, the process can definitely be slowed down. We offer industry-leading corrosion protection using the RGF Environmental FinSaver which uses a galvanic reaction (dissimilar metals in contact and condensation water as the catalyst) to draw corrosion to itself. The FinSaver creates the most attractive place for corrosion to occur, draws corrosion to itself and away from your indoor coil, and is effective at combating both formicary and galvanic corrosion.

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What size comfort system do I need for a building that’s X,XXX square feet?

Despite popular belief, the square footage per ton “rule-of-thumb” is a horribly inaccurate method of sizing comfort equipment. The only way to determine the correct system sizing for your home is to calculate the heat gain/loss in BTUs using ACCA / ASHRAE load calculations. If you consider two different buildings (each 2,000 square feet) – one built in the 1960’s with poor construction quality and the other built to modern code requirements – the square footage per ton method would assume that both buildings require the same size system. This is absolutely not the case! Load calculations consider a number of factors including construction quality, insulation R-values, door and window sizes and types, internal occupants and appliance heat gain, building orientation, etc.

I currently have a 5.0 ton system so that’s what I need when I replace it, right?

Existing system sizing should be used as nothing more than a reference point when looking at options for new system replacements. According to the U.S. Department of Energy, approximately 70% of comfort systems installed (by companies other than Hamstra) are improperly sized for the offices/areas they condition. Another consideration is comfort equipment specifications and performance have changed drastically over the years, so the actual delivered capacity of a 20-year old 5.0 ton system is often quite a bit different than a brand new 5.0 ton system.

Why is the upper level of my office always warmer than the lower level?

On buildings with separate comfort systems for each level, the most common issue we identify is improperly sized equipment. Contractors unfamiliar with load calculations often oversize lower level systems and undersize upper level systems. Having properly sized comfort equipment and ductwork systems installed can often remedy this issue. On multi-story buildings with single systems that condition multiple levels, the upper level is almost always warmer in the summer because heat rises. The best way to remedy this issue without adding a separate comfort system for the upper level would be to have a zone damper/control system installed that would allow for individual temperature control of each level by automatically opening and closing dampers in the ductwork system as necessary.

Why are rooms on the south/west side of my building always warmer during summer afternoons?

Rooms with south or west facing exposure receive the most direct sunlight during our warm summer afternoons, which means those rooms will require more cooling/airflow to keep them as comfortable as the rest of the building. While adjustments can be made to improve airflow to these rooms, items such as skylights and large windows may make it difficult to keep these rooms the exact same temperature as the rest of the structure. Setting your indoor fan for continuous operation to keep the indoor air circulating will help keep temperatures even across the building when the cooling system isn’t running.

Why is my IT room always so hot?

Chances are the additional internal heat gain from the electronic equipment was not accounted for when the comfort system was originally sized. Depending on the specific shortage of capacity/airflow, corrective actions may require replacement of ductwork, air devices, or even comfort equipment to achieve adequate comfort in these rooms.

Why is it so humid in my office?

Living in Southern Arizona, we typically only have notable outdoor humidity for a couple months each year. If you notice that your indoor humidity levels are excessive and it constantly feels muggy inside, your comfort system might be to blame. Having indoor fan operation and system airflow set properly can often make a huge difference in humidity control. Equipment sizing also plays an important role. If your comfort system is oversized for your office and only operates in cooling mode for short periods of time before cycling off, the system will be unable to remove adequate levels of moisture from the indoor air.

I’m building an addition on my office. Can I just add new ductwork from my existing system?

If your existing building comfort and ductwork systems are properly sized, in most cases adding on additional ductwork and air devices will not provide adequate comfort for the addition or the existing home area. Another consideration when adding onto a building is that newer additions made to older structures will feature drastically different construction materials, so having a single comfort system that conditions both areas can result in notable temperature differences between the two types of construction - even if the comfort equipment and ductwork are properly sized.

Why are my utility bills so high?

Comfort equipment is often the largest consumer of electricity in most homes. Having annual maintenance performed can help keep your system(s) running as efficiently as possible by ensuring the refrigerant charge is correct, airflow is set properly, blowers and coils are clean and free of sediment, and all electrical components are working properly. Another factor that can contribute to high utility costs is the sizing of the system. If your comfort system is too small for your office and runs throughout the day without shutting off, your utility bills will reflect this.

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What is the best brand of comfort system available?

The best product for your application is based upon a number of factors. Different product lines from different manufacturers feature various strengths and weaknesses compared to others. For that reason, we always perform an in-depth evaluation to determine the best comfort solution for your needs. The brands and product lines we carry are all subjected to extensive lab and field testing, and we only install the same equipment and products for our clients that we use in our own office. More important than the label on your equipment is the contractor that installs it. Newer comfort systems are becoming increasingly technical and complex, and many of the details overlooked by other contractors can have a huge impact on energy efficiency and system life. The brand name on your equipment is only as good as the installing contactor that stands behind the installation!

What is two-stage cooling / heating and what are the benefits?

Two-stage cooling/heating comfort systems provide additional levels of system capacity. The first stage (often around 70% of total capacity) is used during mild weather conditions and consumes less electricity or gas than single stage systems running at 100% continuously. During extremely warm or cold periods (or when the thermostat set-point is adjusted more than 3 degrees at once), the second stage of cooling/heating is engaged to provide 100% capacity delivery as needed. The main benefit of two-stage comfort is notable annual energy savings compared to single-stage equipment.

What are variable-capacity compressor systems and what are the benefits?

Variable-capacity compressor systems feature hundreds of stages (capacity levels) that allow the systems to modulate compressor speed up and down to deliver only the amount of cooling or heating capacity actually needed in the home. The main benefit of these systems is a notable reduction in utility costs compared to systems that constantly operate at 100% capacity.

What’s the difference between fixed-speed PSC / constant-torque / variable-speed indoor fans?

Fixed-speed PSC fans operate on single speeds for cooling/heating modes and have been commonly installed in comfort systems for the past few decades. This type of motor is being phased out in most newer comfort systems due to new energy efficiency regulations. Constant-torque motors are ECM (Electronically Commutated Motors) with multiple speed taps that are designed to maintain constant torque levels while in operation. These motors offer improved energy efficiency compared to older style fixed-speed PSC fans. Variable-speed indoor fans are also ECM type motors but are designed to maintain a constant CFM (cubic feet per minute). Variable-speed fans are the most energy-efficient and allow a great deal of versatility with airflow adjustments. As opposed to other types of fans that basically operate with On/Off functionality, variable-speed fans slowly ramp up-to and down-from maximum speed which results in quieter operation and less noticeable airflow noise inside your office.

What is a ton rating and what does it mean?

Tonnage ratings refer to the nominal capacity (size) of a comfort system. One ton of capacity equates to 12,000 BTU. Tonnage is somewhat of a loose rating when it comes to true system capacity, because the actual delivered capacity varies among different climate zone, manufacturers, product types, and system efficiency levels. In short, systems with the same tonnage from two different manufacturers can have notably different sensible capacity delivery.

What are SEER / EER ratings and what do they mean?

SEER stands for Seasonal Energy Efficiency Ratio and EER stands for Energy Efficiency Rating. Think of SEER and EER like miles per gallon for cooling system. The higher the SEER / EER, the more energy efficient the cooling system and the less it will cost you to cool your office annually.

What are AFUE ratings and what do they mean?

AFUE stands for Annual Fuel Utilization Efficiency and is a rating for gas fired heating equipment. Think of AFUE like miles per gallon for your heating system. The higher the AFUE, the more of each dollar spent on natural gas (or propane) is used to actually generate heat that’s delivered to your office. In our warm Southern Arizona climate, higher AFUE gas heating equipment is not nearly as common as in colder climate areas due to the increased installation cost with long payback periods.

What are HSPF ratings and what do they mean?

HSPF stands for Heating Seasonal Performance Factor and is a rating for heat pump equipment. Think of HSPF like miles per gallon for your heating system. The higher the HSPF, the more energy efficient the heating system and the less it will cost you to heat your office annually.

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My system isn’t cooling/heating. What can I check before I call for service?

Verify that your thermostat is set to the proper mode (cooling/heating) and the temperature set-point is below (cooling) or above (heating) the current indoor temperature. If you’re handy, you can also check for tripped circuit breakers or blown fuses. Older / weak circuit breakers can trip from time to time, but if the breaker trips repeatedly after being reset, this can indicate an issue with the electrical circuit or your comfort system. If you find a blown fuse, odds are the root cause is something other than the fuse itself. If replacing the fuse gets your system back online, we still recommend having a professional evaluate your system.

How do I operate my thermostat?

If you have recently moved into a new home (or lost your thermostat user manual), don’t worry! The vast majority of thermostat user manuals are available online without special login access. Simply find the model number of your thermostat (typically located on the base plate or rear of the thermostat) and perform a Google search with the model number and words “user manual” – Example: “Nest T3008US user manual.”

What temperature set-points should I use for my cooling/heating?

Different people are comfortable at different indoor temperatures so we recommend keeping your thermostat set to temperatures that keep you the most comfortable. For energy-efficient operation, EnergyStar recommends a cooling set-point of 78 degrees and a heating set-point of 72 degrees. Keep in mind that the lower you keep your thermostat set in the summer (and the higher you keep it set in the winter), the higher your utility bills will be.

Should I turn my thermostat off or drastically change the temperature set-point while I’m at work?

There is a common misconception that turning your thermostat completely off or raising/lowering the temperature 8-10 degrees while you’re away from your home daily will result in energy savings. This is actually not the case! Especially during the summer, when the indoor temperature and humidity increase during the day, your system will work extremely hard to return the home to occupied comfort conditions. The best practice is to set your temperature back no more than 3-5 degrees because setting back further will result in higher utility costs.

Should I set my indoor fan to Auto, On, or Circulate?

The best indoor fan setting for your needs can vary based upon your personal comfort, type of system, and the layout of your home. The “Auto” indoor fan setting operates your comfort system’s indoor fan only when the system is cooling or heating. The “On” fan setting will run your indoor fan continuously regardless of cooling/heating operation to constantly circulate air throughout your home. If your thermostat has a “Circulate” fan feature, using this setting will operate the indoor fan for a few minutes each hour just to circulate some air and prevent stagnant indoor air on mild days when there is no demand for cooling or heating operation.

Should I replace my old thermostat with a programmable thermostat?

Aside from being a mechanical code requirement for new system installations, switching to a programmable thermostat can result in notable energy savings. Most models feature time period functionality so you can program your temperature set-points for multiple time blocks each day. Going a step further, the Nest Professional thermostats we offer are also WiFi compatible so you can make temperature adjustments using your computer, tablet, or smart phone when you’re away from home.

How often should I clean / replace my system’s air filter(s)?

Air filters will load (become dirty) at various rates depending on how often the indoor fan operates, how dusty the indoor air is, number of pets, frequency that exterior doors open/close, etc. The best rule of thumb is to inspect your air filter(s) at least monthly and clean/replace them as necessary. Beware of filters that claim to be “90-Day Filters” because there is simply no way to guarantee that an air filter can be left in place for a 3-month period without becoming dirty and restricting system airflow.

Why does my thermostat say “Check Filter” when I just replaced it?

Thermostat filter reminders are typically set to display after a certain number of days or period of system operation. Your thermostat does not actually monitor the condition or cleanliness of your filters or know when you clean/replace them, so this reminder must be reset.

Do I need to have annual maintenance performed on my comfort system?

Absolutely! In most homes, the comfort systems are among the highest priced pieces of equipment installed, and you should protect your investment. Having proper annual maintenance performed will maximize energy efficiency (keep utility bills low), prevent system breakdowns, prolong the operation life, and maintain your system’s factory warranty coverage.

What system maintenance items can I perform myself?

We recommend keeping filters clean/replaced regularly, keeping plants and debris away from your outdoor units, and leaving the rest to us! HVAC equipment contains advanced electronics and is connected to utilities such as natural gas and high-voltage electricity. Taking safety considerations and factory warranty coverage into account, we do not recommend opening any service panels or attempting any repairs unless you’re a factory trained professional.

I saw my neighbor spraying his outdoor coil with a hose. Should I be doing that?

While keeping your outdoor coil clean is imperative for proper system operation and maximum energy efficiency, spraying it with a hose can actually cause more harm than benefit. Your outdoor unit draws air from the outside of the unit in through the condenser coil, and spraying water from the outside in can actually push surface sediment and debris further into the coil. Properly cleaning condenser coils often requires the application of a specialty cleaner and rinsing the coil in the opposite direction that air flows through it.

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What type of air filter(s) should I be using?

For most applications, we recommend a loose pleat type air filter with a MERV Rating of 8-11. If allergies or excessive indoor dust are of concern, we do offer solutions for high-efficiency indoor filtration and air purification. Care should be taken when considering the use of air filters with a MERV rating above 11 or electronic air cleaners. High efficiency air filtration products are often more restrictive than standard air filters, so care must be taken to ensure that your ductwork system can handle the increased static pressure without causing any damage to your comfort system.

I need better indoor air filtration! What can I do?

If standard air filters aren’t cutting it for you, don’t worry - we can help! The first step to impeccably clean indoor air is to ensure that your ductwork system is tight (leak free). We also offer a wide variety of indoor air quality products such as air cleaners and even air purification.

My comfort system circulates odors from cooking, pets, etc. What can I do?

We have a solution for that! Ask us about indoor air purification using Air Scrubber Plus technology.

How often should I have my ducts cleaned?

In most homes with regular air filter cleaning/replacement, duct cleaning is necessary approximately every 10 years. If air filter maintenance is neglected or your duct system has leaks, sediment can accumulate within the duct system more frequently.

Is there any way to seal up leaky ductwork without replacing it?

Absolutely. Our patented Aeroseal process enables us to seal duct systems from the inside without having to replace duct or cut drywall to seal duct externally. Ask us for details!

How can I tell if my ductwork system has leaks?

Some indicators to watch for include excessive indoor dust levels, dirt trails at supply register openings, and cold air movement in attics/cavities where duct is present during cooling operation. If you think your duct system is leaky but aren’t positive, we can perform a duct blaster test and tell you exactly how much leakage is present.

Can I save money by having my leaky ductwork sealed?

Aside from the associated health and indoor air quality benefits, having leaky duct systems sealed can also save you quite a bit of money! The U.S. Department of Energy reports the typical home may lose from 20 to 30% of its conditioned air due to leaky ducts. As a result, your comfort system works harder and longer, consumes much more energy, and wears out sooner. The more leaky the duct system, the more savings to be had, but we have seen annual energy savings as high as 30% after performing our patented Aeroseal duct sealing process!

Is it okay to close off supply registers in rooms that are unoccupied?

To attempt to save money on utility costs, many residents tend to close off supply registers in rooms that are rarely occupied. In most applications, we don’t recommend closing off more than 1 supply air register per system. Your comfort equipment and ductwork systems are designed and balanced to move a specific volume or air to each space in your home. Closing off or covering multiple registers will not result in any energy savings and will actually increase the static pressure in your duct system and potentially cause damage to your comfort system.

Is it okay to place furniture in front of return grilles?

System return grilles should not be partially or completely blocked by furniture, wall coverings, etc. under any circumstance. Restricting proper return airflow to your comfort system will reduce energy efficiency, system performance, and can cause damage to expensive system components.

Why does my furnace produce an odor at the beginning of each heating system?

The annual furnace odor is common and a result of dust accumulating on the heat exchanger over the months of inactivity. The high temperature of the heat exchanger burns the dust off over the first few heating cycles, and this odor should dissipate within 24-48 hours under normal circumstances. If you notice a smell that appears to be more “burning” or “electrical” in nature, turn your system off and contact us immediately!

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Does my comfort system need surge protection?

Most homeowners invest in surge protection for their televisions and computers, but neglect to protect the most expensive equipment in their homes – the cooling and heating systems! Comfort systems contain many expensive electrical components such as compressors, fan motors, and control modules, and manufacturer warranties do not cover part failure resulting from power surges. The Intermatic AG3000 surge arrestors we offer provide industry-leading protection against both major surges and spikes (lightning, brownouts, utility spikes) and micro surges.

I have a whole-house surge protector installed, so my HVAC equipment is safe, right?

Not necessarily! While “whole-house” surge protectors installed at your main electrical panel provide protection against major surges and spikes from everything outside your meter, the average home in the U.S. experiences hundreds of yearly micro surges within the home’s electrical service. Large appliances such as refrigerators, motors, pool equipment, hair dryers, and even comfort systems create micro surges within your electrical system when starting/stopping. While these surges typically do not result in immediate system failure, over time they degrade the integrity of electrical components and can result in premature electrical component failure.

What is condensate overflow protection and why do I need it?

As your cooling system removes heat from the indoor air, condensation is produced and drained from the indoor coil – as much as 5-15 gallons per day during high-humidity months! If your drain line becomes plugged with sediment or insects, all of this water is still going to drain somewhere. Condensate overflow conditions can quickly result in thousands of dollars in damage to walls, ceilings, and flooring and result in microbial growth if left unnoticed. The AquaGuard condensate safety overflow devices we offer detect overflow conditions and lock-out system operation to prevent your cooling system from creating additional condensation until the drain issue is corrected.

Is there anything I can do to prevent my indoor coil from rusting/corroding prematurely?

While there’s unfortunately no way to entirely prevent indoor coil corrosion over time, the process can definitely be slowed down. We offer industry-leading corrosion protection using the RGF Environmental FinSaver which uses a galvanic reaction (dissimilar metals in contact and condensation water as the catalyst) to draw corrosion to itself. The FinSaver creates the most attractive place for corrosion to occur, draws corrosion to itself and away from your indoor coil, and is effective at combating both formicary and galvanic corrosion.

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What size comfort system do I need for a home that’s X,XXX square feet?

Despite popular belief, the square footage per ton “rule-of-thumb” is a horribly inaccurate method of sizing comfort equipment. The only way to determine the correct system sizing for your home is to calculate the heat gain/loss in BTUs using ACCA Manual J load calculations. If you consider two different homes (each 2,000 square feet) – one built in the 1960’s with poor construction quality and the other built to modern code requirements – the square footage per ton method would assume that both homes require the same size system. This is absolutely not the case! Manual J load calculations consider a number of factors including construction quality, insulation R-values, door and window sizes and types, internal occupants and appliance heat gain, building orientation, etc.

What are Manual J, Manual S, and Manual D load calculations and why are they important?

Manual J load calculations determine the heat gain/loss of your home in BTUs. Manual S calculations verify proper equipment sizing in conjunction with the Manual J load requirements. Manual D duct calculations are used to size ductwork system trunks and branches to achieve proper airflow and velocity to each room in your home. Each of these calculations are imperative for comfort system sizing, design, and installation.

I currently have a 5.0 ton system so that’s what I need when I replace it, right?

Existing system sizing should be used as nothing more than a reference point when looking at options for new system replacements. According to the U.S. Department of Energy, approximately 70% of residential comfort systems installed (by companies other than Hamstra) are improperly sized for the homes/areas they condition. We always perform ACCA Manual J load calculations to determine the proper system size for your home. Another consideration is comfort equipment specifications and performance have changed drastically over the years, so the actual delivered capacity of a 20-year old 5.0 ton system is often quite a bit different than a brand new 5.0 ton system.

Why is the upper level of my home always warmer than the lower level?

On homes with separate comfort systems for each level, the most common issue we identify is improperly sized equipment. Contractors unfamiliar with Manual J load calculations often oversize lower level systems and undersize upper level systems. Having properly sized comfort equipment and ductwork systems installed can often remedy this issue. On multi-story homes with single systems that condition multiple levels, the upper level is almost always warmer in the summer because heat rises. The best way to remedy this issue without adding a separate comfort system for the upper level would be to have a zone damper/control system installed that would allow for individual temperature control of each level by automatically opening and closing dampers in the ductwork system as necessary.

Why are rooms on the south/west side of my home always warmer during summer afternoons?

Rooms with south or west facing exposure receive the most direct sunlight during our warm summer afternoons, which means those rooms will require more cooling/airflow to keep them as comfortable as the rest of the home. While adjustments can be made to improve airflow to these rooms, items such as skylights and large windows may make it difficult to keep these rooms the exact same temperature as the rest of the home. Setting your indoor fan for continuous operation to keep the indoor air circulating will help keep temperatures even across the home when the cooling system isn’t running.

Why is my home office / theater always so hot?

Chances are the additional internal heat gains from the office or audio video equipment were not accounted for when the comfort system was originally sized. Depending on the specific shortage of capacity/airflow, corrective actions may require replacement of ductwork, air devices, or even comfort equipment to achieve adequate comfort in these rooms.

Why is it so humid in my home?

Living in Southern Arizona, we typically only have notable outdoor humidity for a couple months each year. If you notice that your indoor humidity levels are excessive and it constantly feels muggy inside, your comfort system might be to blame. Having indoor fan operation and system airflow set properly can often make a huge difference in humidity control. Equipment sizing also plays an important role. If your comfort system is oversized for your home and only operates in cooling mode for short periods of time before cycling off, the system will be unable to remove adequate levels of moisture from the indoor air.

I’m building an addition on my home. Can I just add new ductwork from my existing system?

If your existing home comfort and ductwork systems are properly sized, in most cases adding on additional ductwork and air devices will not provide adequate comfort for the addition or the existing home area. Another consideration when adding onto a home is that newer additions made to older homes will feature drastically different construction materials, so having a single comfort system that conditions both areas can result in notable temperature differences between the two types of construction - even if the comfort equipment and ductwork are properly sized.

Why are my utility bills so high?

Comfort equipment is often the largest consumer of electricity in most homes. Having annual maintenance performed can help keep your system(s) running as efficiently as possible by ensuring the refrigerant charge is correct, airflow is set properly, blowers and coils are clean and free of sediment, and all electrical components are working properly. Another factor that can contribute to high utility costs is the sizing of the system. If your comfort system is too small for your home and runs throughout the day without shutting off, your utility bills will reflect this.

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What is the best brand of comfort system available?

The best product for your application is based upon a number of factors. Different product lines from different manufacturers feature various strengths and weaknesses compared to others. For that reason, we always perform an in-depth home evaluation to determine the best comfort solution for your needs. The brands and product lines we carry are all subjected to extensive lab and field testing, and we only install the same equipment and products for our clients that we use in our own homes. More important than the label on your equipment is the contractor that installs it. Newer comfort systems are becoming increasingly technical and complex, and many of the details overlooked by other contractors can have a huge impact on energy efficiency and system life. The brand name on your equipment is only as good as the installing contactor that stands behind the installation!

What is two-stage cooling / heating and what are the benefits?

Two-stage cooling/heating comfort systems provide additional levels of system capacity. The first stage (often around 70% of total capacity) is used during mild weather conditions and consumes less electricity or gas than single stage systems running at 100% continuously. During extremely warm or cold periods (or when the thermostat set-point is adjusted more than 3 degrees at once), the second stage of cooling/heating is engaged to provide 100% capacity delivery as needed. The main benefit of two-stage comfort is notable annual energy savings compared to single-stage equipment.

What are variable-capacity compressor systems and what are the benefits?

Variable-capacity compressor systems feature hundreds of stages (capacity levels) that allow the systems to modulate compressor speed up and down to deliver only the amount of cooling or heating capacity actually needed in the home. The main benefit of these systems is a notable reduction in utility costs compared to systems that constantly operate at 100% capacity.

What’s the difference between fixed-speed PSC / constant-torque / variable-speed indoor fans?

Fixed-speed PSC fans operate on single speeds for cooling/heating modes and have been commonly installed in comfort systems for the past few decades. This type of motor is being phased out in most newer comfort systems due to new energy efficiency regulations. Constant-torque motors are ECM (Electronically Commutated Motors) with multiple speed taps that are designed to maintain constant torque levels while in operation. These motors offer improved energy efficiency compared to older style fixed-speed PSC fans. Variable-speed indoor fans are also ECM type motors but are designed to maintain a constant CFM (cubic feet per minute). Variable-speed fans are the most energy-efficient and allow a great deal of versatility with airflow adjustments. As opposed to other types of fans that basically operate with On/Off functionality, variable-speed fans slowly ramp up-to and down-from maximum speed which results in quieter operation and less noticeable airflow noise inside your home.

What is a ton rating and what does it mean?

Tonnage ratings refer to the nominal capacity (size) of a comfort system. One ton of capacity equates to 12,000 BTU. Tonnage is somewhat of a loose rating when it comes to true system capacity, because the actual delivered capacity varies among different climate zone, manufacturers, product types, and system efficiency levels. In short, systems with the same tonnage from two different manufacturers can have notably different sensible capacity delivery.

What are SEER / EER ratings and what do they mean?

SEER stands for Seasonal Energy Efficiency Ratio and EER stands for Energy Efficiency Rating. Think of SEER and EER like miles per gallon for cooling system. The higher the SEER / EER, the more energy efficient the cooling system and the less it will cost you to cool your home annually.

What are AFUE ratings and what do they mean?

AFUE stands for Annual Fuel Utilization Efficiency and is a rating for gas fired heating equipment. Think of AFUE like miles per gallon for your heating system. The higher the AFUE, the more of each dollar spent on natural gas (or propane) is used to actually generate heat that’s delivered to your home. In our warm Southern Arizona climate, higher AFUE gas heating equipment is not nearly as common as in colder climate areas due to the increased installation cost with long payback periods.

What are HSPF ratings and what do they mean?

HSPF stands for Heating Seasonal Performance Factor and is a rating for heat pump equipment. Think of HSPF like miles per gallon for your heating system. The higher the HSPF, the more energy efficient the heating system and the less it will cost you to heat your home annually.

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