Frequently Asked Questions
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A Manual J is an ACCA Certified calculation of the heating and cooling loads of a home or commercial structure.
The Manual J is a scientific way to size equipment, unlike the traditional method of square footage and the age of the home which is inaccurate and inexact.
To properly calculate loads, we take the known insulation values of walls, floors, and attics, the window sizes and quantity, orientation, and building tightness, and insert this information into the software to form a room by room load calculation of your home.
These building envelope values are then calculated using the ASHRAE Climatic Design Conditions for your address, and we are given an accurate assessment of your home’s heating and cooling needs.
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A Manual S is equipment selection. The Manual S takes into account the load of the house, the ASHRAE climate data, including ambient temperature and humidity, duct system design and losses, and static pressure availability.
The Manual S is the best way to size a system for a home, because it takes outside variables into account.
The AHRI Database is commonly used a sizing tool, but most contractors don’t realize that the testing data provided by the AHRI is one very small piece of the puzzle. The AHRI gives a single data point, while equipment manufacturers give a range of data points based on pressures, humidity, etc.
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A Manual D is the duct system design. Each duct, fitting, and register can be customized to size and design for proper airflow with the selected equipment.
The Manual D confirms that the system selected based on the heating and cooling load will provide adequate airflow.
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A properly done, ACCA Certified Manual J takes into account the building qualities, building envelope types, and specified details of an existing or new construction home, and calculates the heating load, sensible cooling load, and latent cooling load to provide you with a comprehensive understanding of your homes needs.
In the past, HVAC contractors calculated the loads of a house based on the square footage and age of a house, with a buffer to ensure that the heating and cooling loads were exceeded, preventing a call back for a system that “couldn’t keep up.” Changes in building codes and HVAC technology has led to a more scientific approach to comfort, that uses data instead of estimating.
Modern HVAC equipment, specifically heat pump systems, have a range of capacities that they operate best in, and oversizing a heat pump leads to high electricity usage and short cycling. Oftentimes, this isn’t discovered by the homeowner or the builder until the winter heating bill arrives, or there is mechanical breakdown from short cycling. Properly sizing a system saves you money each month, and in the long term by extending the life of your HVAC system.
The key informative components of the Manual J are the heating load, sensible cooling load and the latent cooling load.
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The heating load tells us how much heat your home will require on the design degree day (the average coldest day of the year in your area), when there is no radiant heat from the sun. This heating load is used to ensure you stay warm inside, when it is cold outside.
The heating load is the amount of heat lost through the building envelope that needs to be replaced by the heat from your heating system.
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There are two parts to the cooling load.
Sensible Cooling Load: The Sensible Cooling Load is the amount of sensible heat (heat that can be directly and easily measured with a thermostat) that your system needs be able to remove on the cooling degree day (the average hottest day of the year in your area), during the daytime while radiant heat from the sun enters your home.
Latent Cooling Load: The Latent Cooling Load is how much moisture your system needs to be able to remove during the most humid times of the year. Latent heat cannot be measured with a thermostat and is moisture related.
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We do in-home testing, including blower door tests, duct leakage tests, leakage to outside tests, and more.
Blower door testing measures the building envelope leakage rate, and fits well with our air sealing recommendation service. While the blower door is running, it is easy to pinpoint the areas of leakage to find an air sealing solution, reducing the heating demand for your home and saving in energy costs.
Duct testing measures the total leakage from an existing duct system, highlighting areas where corrections can be made, saving you on your heating and cooling bill.
Leakage to outside testing measures the duct leakage that is outside of the thermal envelope. This test is done by depressurizing the house at the same pressure as the duct system, to only measure duct losses to unfinished space or the exterior of the house.
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Insulation upgrades:
We review your quotes, discuss insulation types, and discuss your future plans to provide you with a detailed report.
HVAC & water heater quote comparisons:
It can be challenging to work through and understand HVAC and water heater quotes. There are many ways to asses the efficiency of a system and predict the efficacy of the system once installed, but you need to know what to look for.
We offer personalized reports comparing efficiency data and mechanical specs to ensure you make a decision you are happy with. We send you verified AHRI efficiency data and highlight key areas of focus.
Energy efficiency upgrades:
This includes a wide variety of options, such as air sealing and appliances.
We offer air sealing advice and best practices, and we look through our appliance database to compare refrigerators, dishwashers, clothes washers, and clothes dryers.
Ventilation:
We provide our ventilation guidelines and requirements, and provide ERV, HRV, and ventilation fan efficiency comparisons and best practices.
ERVs & HRVs are still a mystery to many HVAC contractors, and installing the wrong one can cost you significantly.
It is important to have a deep understanding of what to look for, and we provide better options in many cases.
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For Manual J, S, D
Go to the Manual J, S, D tab at the top of the page.
We have a form we ask you to fill out, and we ask that you provide us with a measured floor plan with location and measurements of the windows.
By giving us this information, we can provide you with a precise Manual J report that you can be confident in. When the form is submitted, one of our qualified team members will recieve the information, and get to work.
You will recieve the Manual J, along with the invoice for the service, within three buisiness days. We offer rushed service as well, so there is an option to recieve your Manual J within 24 hours.
Quote Comparison Service
This service works differently.
From the Energy Consulting tab, you will select one of our four options, add to cart, and check out.
We ask that you email your quotes and questions to Info@NortheastEnergyAdvisory.com, and we will create a comparison of your options for you.
We offer our professional advise on what quote is best for you, and any suggestions we have to improve on those quotes.
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We have a few companies that we subcontract for heat pump installations in the New England area. We have worked with them for the last five years and we are happy to provide a quote to you.