Sizing & Design Materials

NEEP — Cold Climate Sizing Support Tools

The cold climate heat pump sizing support tools, which include a helpful tutorial video on how to use them, help users to select cold-climate air source heat pump (ccASHP) products that are sized to best match the peak and annual heating needs of a home or heating zone. The tools, functioning within the NEEP ccASHP Product List website, include a search function and a product-level analysis. The search function helps users compare multiple products based on the search criteria. The product view displays system and load-matching data, and provides a visual for how a specific heat pump’s capacity matches the heating load across the home’s winter temperatures.

NEEP — Sizing and Selecting Air Source Heat Pumps in Cold Climates

Selecting the right cold climate heat pump requires careful consideration of the heating load, the intended use of the system, and the configuration of the new unit. With so many heat pump configurations available, it can be easy to make mistakes. This guide provides an overview on sizing and selecting heat pumps that maximize performance, efficiency, and customer satisfaction.

Improving Installations by Weatherizing First

Nine out of ten homes in the U.S. are under-insulated, and air leakage can account for 25-40% of the energy used for heating and cooling in a typical home. Basic weatherization and building-envelope improvements, such as air-sealing and increased attic insulation, can reduce the design heating and cooling loads of a New York State home significantly. This often allows an installer to use a smaller heat pump with a simpler distribution system. This leads to improved customer comfort, lower installation and operating costs, and higher customer satisfaction with a heat pump system.

Reduce Over-Zoning

Over-zoning a heat pump system may result in system oversizing, higher costs, comfort issues, and call backs. Proper zoning can better accommodate occupants with different temperature and humidity preferences. It can also provide uniform temperature and humidity throughout homes with varying heating and cooling loads. Heat pumps allow for new and useful styles of zoning you can’t get from traditional fossil fuel heating and split air conditioning systems.

Don’t Oversize

Oversizing a heat pump is more problematic than oversizing a fossil fuel furnace or boiler. The energy and comfort impacts of an oversized air-source heat pump can take effect beginning with systems sized at 120%, and severe impacts of oversizing can begin with systems sized above 150% of the building load. At a certain point, the system may be unable to achieve heating or cooling entirely. In cold-climates with humid summers a system that’s oversized for heating may be unable to functionally dehumidify the air which can lead to mildew, mold, and wood-rot in extreme cases. In all, oversized systems are costly to the homeowner and reduce comfort.

Multi-Head vs. Single-Head Split Systems

Multi-head and single-head ductless split systems can be used to heat and cool almost any home type. How these systems are configured and applied can have substantial effects on their efficiency, efficacy, and lifespan. This guide provides more insight into the key differences between multi-head and single-head systems and how to know which one is right for the home.

Duct Evaluation Guide

The Cold-Climate Duct Evaluation Guide explains why it is important to properly size ducts for air source heat pumps, how to assess existing ducts to determine if they should be reused, modified, replaced, or decommissioned, impacts on duct replacement costs, and best practices when assessing existing ducts. The guide also provides the National Comfort Institute’s (NCI) Standardized Duct Sizing Tables for easy of referencing.

Installer’s Guide to Assessing Residential Electrical Service

Do You Have Enough Juice?

When installing a new heat pump system, the home must have sufficient electric system capacity to provide the heat pump’s power. Underserviced homes may require an amperage upgrade from the utility. In many cases the homeowner can avoid this cost by installing technology alternatives that reduce peak amperage, efficiently utilizing breaker space in the electric panel, adding subpanels, or some combination thereof. This moment of decision on how to adapt or update a home’s electrical capacity is a prime opportunity for heat pump contractors to discuss long-term plans with the homeowner and gain momentum toward full electrification, preventing homeowners from having to make additional expensive electrical changes down the line.

This guide will assist HVAC installers in assessing a home’s electrical system before engaging with an electrician or starting the heat pump installation process.

This guide includes steps to:

1. Determine the home’s electrical service capacity
2. Discuss long-term plans for the home
3. Estimate existing and future peak electrical loads
4. Provide options to install clean heat in electric-system-constrained homes
5. Anticipate the electrical work

Heat Pump Home Runs

Heat Pump Home Runs is a set of winning design strategies for full displacement heat pump installations. Contractors can view heat pump design options for various common home types and be reminded of key technical considerations to review on each job.

• 1-story Ranch (PDF)
• 1-story Extended Ranch (PDF)
• 1.5 Story Cape Cod (PDF)
• 2-story Colonial (PDF)
• Manufactured (PDF)
• Townhouse (PDF)

Air Source Heat Pump: Efficiency Ratings Explained – DOE Appendix M1

The Air Source Heat Pump: Efficiency Ratings Explained – DOE Appendix M1 sheet explains the new efficiency metrics (HSPF2, SEER2, and EER2), the new test procedure they came from, and how these changes impact eligibility for NYS Clean Heat utility incentives and 25C federal tax credits from the Inflation Reduction Act.