Quality HVAC design, install and testing
HVAC systems are often poorly designed and installed leading to many problems including
Improper sizing leads to high energy use
Short cycling means they heat or cool properly
Ducts don’t deliver conditioned air
Unequal heating and cooling means uneven comfort
Filters that dont remove impurities from the air
There are a variety of ways to make sure a home has a quality HVAC system that avoids common problems. Here is how True Turtle designs an HVAC system for high performance.
Designing in lower energy use from the very beginning
Homes use 40-50% of their energy on space heating and cooling. Early choices in the design have an enormous impact on energy use for the long term.
Load calculations mean higher comfort and lower energy use
Bigger is NOT better when it comes to HVAC systems. Many contractors rely on “Rules of thumb” to size a HVAC system. This leads to grossly oversized systems that use more energy than is necessary and provide poor comfort in a home due to short cycling.
There is a proper way to size a HVAC system. The contractor performs a special energy model that calculates the heating and cooling load. It’s called a Manual J. Most contractors either do not perform a Manual J, (instead relying on rules of thumb) or they do the Manual J grossly wrong.
True Turtle always performs a Manual J.
In fact…our Manual J is quality checked by our LEED rater to assure it’s done right.
Our equipment sizing is on average, about 30% smaller than what a “rule of thumb” designed system. Saving the eventual owner money while providing excellent comfort.
Energy saving layout and design
Energy saving air handler placement
The air handler is inside the envelope. Many times it is in the attic or garage where it loses heating and cooling to extreme temperatures.
The air handler is centrally located so that duct runs are short and straight. Every bend means you lose 25% of the air flow due to turbulence. We specifically locate air handlers to minimize bends.
Energy saving duct layout design
All ducts are inside the envelope…many times contractors locate ducts in exterior walls or even worse in attics or crawlspaces where they lose heating and cooling to the extreme temperatures and leakage.
No flex duct unless required by code. Flex duct is not smooth on the inside and air flow is lost. Many contractors will duct an entire home with flex duct, resulting in uncomfortable rooms and an octopus in your basement or attic.
Quality duct installation, verified by testing
Ducts are evil.
Energy Star reports that for any given house "about 20 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts. The result is higher utility bills and difficulty keeping the house comfortable, no matter how the thermostat is set".
If heating and cooling is ~50% of a buildings energy use that 10% of the energy used in your home wasted!
Duct leakage is so important that the tested rate has a huge effect on the predicted energy use of a building.
Quality testing of ducts ensures high performance
We perform a series of duct blaster tests to ensure high performance:
1st test: During construction before close in so we can correct deficiencies
2nd test: Post completion to get the final measured rate
What is a duct test?
A duct blaster test is performed by sealing up all duct registers, pressuring the system and measuring the leakage. By adding fog to the test you can visually find leakage points for correction.
Higher performance, easy to maintain and service HVAC equipment
Our HVAC equipment is NOT super special, whiz bang, ultra high performance equipment. We don’t need whiz bang because we’ve focused on quality construction of a high performance envelope with super air sealing, tight ducts, super insulation, high performance windows, etc.
We install only slightly higher performing, brand name, low maintenance equipment. Our goal is comfort that is durable, tried and true, and easy to service and maintain.
Our typical performance specifications for a 2,000-2,400 sf gut renovation row home are:
2-2.5 Ton system
This equipment is about 20-30% more efficient than builder grade.
What do the above numbers mean?
Seasonal Energy Efficiency Ratio (SEER):
SEER indicates the relative amount of energy needed to provide a specific cooling output. The higher the SEER, the more efficient the equipment. Many older systems have SEER ratings of 6 or less. However, the minimum SEER allowed today is 13.
Heating Seasonal Performance Factor (HSPF):
HSPF is specifically used to measure the efficiency of air source heat pumps. It is the ratio of heat output to electrical power for a season. The most efficient heat pumps have an HSPF between 8-10.
HVAC systems also contain ventilation and air filtration…which are also designed and installed better in a high performance building.