Greener Homes ProgramWebinar on Hot2000 and heat pumpsJuly 22, 2021
2About the WebinarPhone lines muted during presentationUse question & answer function in the chat
3AgendaHOT2000 and CSA F280 (25 min)Air Source Heat pump and Cold Climate Heat Pumps (30 min)Eligibility list selection processWhat does sizing for the entire home mean?Are hybrid systems eligible?Can existing and new HP scenarios be accommodated?Questions and Answers (20 min)
4HOT2000 is:Modeling tool to assess energy consumption (GHG and GJ savings) ofhousessystematic analysis modules for heat losses and gains; solar gains; internal gainsCalculations for system sizing (for winter and summer design days) and annual energy analysisBased on a number of assumptions and Standard Operating Conditionsto ensure comparabilityRelying on a number of similar equations / formulas used for F280 for theheating and cooling loadsUsed by energy advisors that are usually not HVAC specialists
5HOT2000 is not:HOT2000 is not a specific HVAC design toolShould not be considered as certification tool to CSA F280For the HVAC contractor:Choice to use HOT2000 estimates for design (heating and cooling)loadsData coming from HOT2000 could be used to confirm if in the right‘ballpark’ but does not replace necessary calculations that have tobe done by an HVAC contractor using F280.
6Comparison of HOT2000 and F280 Compared the HOT2000 source code and CSA F280-12requirement clauses Assessment of archetype homes to show estimates ofheating and cooling capacity using HOT2000
7CSA Standard F280:Provides calculation methods for determining the output capacity ofall types of applicable residential space heating and coolingappliances to maintain specified indoor environmental conditions inCanadian homesApplies to Part 9 of the National Building Code of CanadaAnnex B of F280-12 states that – “enhancements were basedlargely on work that was done by Natural Resources Canada intheir development of the current versions of the HOT 2000 EnergySimulation Software”This Standard does not cover the detailed design and installation ofresidential space heating and cooling systems.
8F280-2012 vs HOT2000 design loadsAir infiltrationsF280-2012HeatingCoolingHOT2000AIM2 modelAIM2 model0 ACH Heating Capacity: F280 and HOT2000 use AIM2 model for determining the airinfiltration heat losses and gains Cooling capacity: F280 uses AIM2 model and HOT2000 ignores the natural airexchange Implications on capacity calculations None for the heating minor difference in cooling capacity as indoor/outdoor temperature difference issmall during the summer months
9F280-2012 vs HOT2000 design loadsHRV efficiencyF280-2012HOT2000HeatingASEF at: Flow closest to Principal flow rate Temperature closest to design temperatureSRE at: Flow provided by user -25 CCoolingASEFTRE*Note: The ASEF (Apparent Sensible Effectiveness) is not published by the HVI anymore. It has been replaced in heating by the ASRE (Adjusted Sensible Recovery Efficiency), a value that would be better suited forthe calculation of the heating load as it accounts for various losses that result in heating loads. In cooling, the available value is the TRE (Total Recovery Efficiency). The TRE applies to the enthalpy and not thetemperature so one should be careful, when using a TRE measured for an ERV, not to apply it directly to the sensible load likeis done in the standard.
10F280-2012 vs HOT2000 design loadsRepartition of ventilation and infiltration loadsF280-2012HOT2000According to room level (storey) Larger loads for lower rooms (in infiltration) Lower loads for higher rooms (in exfiltration)According to Above Grade volume Larger loads for greater above grade portionAccording to ratio of conductive losses/gainsover those of entire levelAccording to ratio of conductive losses/gainsover those of entire house
11F280-2012 vs HOT2000 design loadsSensible internal gains (cooling)F280-2012AppliancesOccupantsHOT2000Max (800 W, 4 W/m2floor)70 W/occupant0WNote. HOT2000 assumes that:The appliance gains are separated as: 57% in the kitchen 43% in the laundry roomThe occupants are located in: The living room if there is one The dining room if there is no living roomWhen calculating the appliance gains corresponding to 4 W/m 2, HOT2000 evaluates the floor areaas the house volume divided by a 2.5 m average height.
12F280-2012 vs HOT2000 design loadsLatent cooling loads (CLlat)F280-2012ApproachConditionsBased on typical AC Sensible Heat Ratio- 30% of sensible cooling loadsDefaultHOT2000HOT2000Detailed calculation- 67 W lat/occupant- Infiltrations and ventilationFlow DHD 3Where DHD is the design humidity difference 3 is an approximation of the product of the densityof air and the latent heat of vaporization of water Small or well-insulated houseswith relatively large air changeratesOr Houses with unusual moisturesources
13F280-2012 vs HOT2000 design loadsNegative cooling loads from basementsF280-2012HOT2000Set to zeroSubtracted from system capacity
14Capacity calculationsHeating capacity – There is one difference in how F280 treats HRVefficiency. There may be a small difference in capacity calculation.Cooling capacity – there are several difference between HOT2000and F280
15ConclusionsHOT2000 is primarily designed to assess GHG and GJ consumption based on ahigh number of variables, including heat gain/loss.Results from HOT2000 could be considered as a close approximation to F280 assome of the calculation algorithms used for F280 were derived from HOT2000and are compatible.Even if close, those outputs do not replace dedicated design calculations. Thesecalculations have to be performed by HVAC contractor / installer.Typically, the mechanical contractor is to perform their own calculations for theright sizing of equipment to be installed in the house based the building envelopecharacteristics in place at the time of the HVAC system installation, includingupgrades that the homeowner is committed to prior to the HVAC installation.
16ASHP selection criteria for Greener HomesENERGY STAR certified heat pump systemsThe United States Environmental Protection Agency (EPA)/Consortium for EnergyEfficiency (CEE) American Heating and Refrigeration Institute (AHRI) certified directorywas used as a base to generate the ENERGY STAR certified/qualified ASHP productsfrom the March 2021 versionThe ENERGY STAR ASHP lists were filtered further based on the active status and theperformance eligibility criteria listed below:Minimum total rated heating capacity at 8.3 C of 3.52kW (12,000 Btu/h)Heating Seasonal Performance Factor (HSPF) (AHRI Climate Region Zone IV) 10Only the products listed as sold in Canada or “USA and Canada” were included in the list
17ccASHP selection criteria for Greener HomesThe Northeast Energy Efficiency Partnership (NEEP) list was used as a base togenerate the ccASHP qualified units from the March 2021 versionAs the NEEP ccASHP list did not provide information on which product is sold inCanada, a note was added to the eligibility criteria specifying that all productsmust be purchased in CanadaThe NEEP ccASHP list was filtered further based on the active status and theperformance eligibility criteria listed below:a) minimum total rated heating capacity at 8.3 C of 3.52kW (12,000 Btu/h)b) HSPF (AHRI Climate Region Zone IV) 10
18ccASHP selection criteria (cont’d)c)d)e)compressor must be variable capacity with three or more distinct operatingspeeds, or continuously variable speedcoefficient of performance (COP) of 1.8 at -15 C (5 F) (at maximum capacityoperation);capacity maintenance (Max -15 C (5 F)/Rated 8.3 C (47 F)) 70%NOTE: In the event that an ASHP double qualified as an ENERGY STAR certified ASHP and accASHP, the heat pump was only included the ccASHP on the list, for grant dollar level purposes.
19Sizing for the entire homeThe ASHP and ccASHP systems are intended to service the entire homea)Heat pump is capable of distributing heat throughout the entire house regardless if it is acentral or a ductless systemb)In case of ductless systems a minimum of two indoor heads is requiredc)No grants for heat pumps that only service a portion of the house only, such as one room, oronly a home additionThe heat pump system must be sized to accomplish the majority of the annualheating needs of the house but not necessarily all of the heating needs The design should account for the anticipated heat requirements after otherplanned energy efficiency upgrades that will be implemented by the homeowner(e.g. building envelope upgrades)
20Toolkit for air source heat pump sizing and selectionNatural Resources Canada has developed a package of materialsrelated to air source heat pump (ASHP) sizing and selection,intended for use by mechanical system designers andrenovation contractors.These materials are designed to assist with sizing and selectingASHPs for Canadian climates, in both new and existing (retrofit)residential r-source-heat-pumpsizing-and-selection/23558New version (v1.1) now available for download on NRCan website
21NRCan ASHP Guide and Tool - OverviewOption A: Emphasis on cooling Client interest is primarily on cooling.The target capacity of the ASHP is based on the cooling load, with the high-stage coolingoutput of the ASHP matching a target cooling capacity range – defined as 80% to 125% ofthe design cooling load.Option B: Balanced heating and cooling Installations where both cooling and heating are important.The target capacity of the ASHP is based on the low-stage cooling output being within thetarget cooling capacity range.This criteria leads to the selection of a larger unit, such that the ASHP can meet a greaterportion of the heating load throughout the year
22NRCan ASHP Guide and Tool – Overview (cont’d)Option C: Emphasis on heating The ASHP is sized to cover the majority of annual heating demands of a building, with coolingperformance of secondary interest.The target heating capacity of the ASHP is the heating load of the building at - 8.3 C, so that theunit is sized to provide a major portion of the heating required.Hybrid (e.g. gas furnace paired with an ASHP) systems are also possible under this Option in theGuide.Option D: ASHP as the sole heating source The ASHP is sized based on heating requirements.However, in Option D, the unit is to be used as the sole source of heating (a back-upheating system might still be required in some cases).The target heating capacity of the ASHP is therefore the design heating load of thebuilding at the heating outdoor design temperature.
23ASHP sizing strategies for Greener Homes ProgramOption B: Balanced heating and cooling – for locations where theheating outdoor design temperature is greater than - 8.3 C (e.g.Victoria, Vancouver)Option C: Emphasis on heatingOption D: ASHP as the sole heating sourceUse Option C and D – majority of Canada, except for a few cities on west coast.
24Additional eligibility criteria for heat pumpsEnergy advisor must recommend space heating as part of the energy efficiencyupgradesHomeowner can decide on a ASHP or a ccASHP as a way to improve theenergy efficiencyThe selected heat pump must be on the lists of eligible ASHP or ccASHPproductsIn the case of ductless systems (mini-split systems, multi-split systems), aminimum of two indoor head units are required and the ductless system mustbe sized to provide heat for the entire home.In the case of a mini-split system with one outdoor unit and one indoor head, aminimum of two mini-split systems would need to be installed to qualify for theGreener Homes grant, because a minimum of two indoor heads is required.
25Hybrid systemsHybrid systems are composed of an electric ASHP/ccASHP component and asupplementary fossil fuel furnace component, under a single optimized controlstrategyThe purpose of the hybrid heating system is to operate the ASHP as the primaryheating system and switch to supplementary system when the ASHP hasinsufficient capacity and/or it is economically beneficial to do soHybrid systems could be appropriate in cases such as: Homeownerwants to operate the heat pump during shoulder seasons and when outdoortemperatures are milder and then operate the gas furnace in very cold temperatures Homeowner is interested in heat pumps for energy efficiency, has access to low gas utility rates,and would like to have flexibility of dual-systemOnly the electric ASHP/ccASHP component of a hybrid system is eligible for aGreener Homes incentive
26Heat Pump System – Existing and NewScenario – Home owner has an existing heat pump and would like to addadditional heat pumps to have a system which distributes heat to theentire homeThe additional heat pump(s) would be eligible for the Greener HomesGrant provided they meet the program criteria and heat pumps arerecommended by the Energy AdvisorThe new heat pump system eligible for the grant must include a minimum of 2 indoorheads if the installed system is ductless.All other eligibility criteria for the new heat pump system must also be met, includingminimum total rated heating capacity at 8.3 C of 3.52kW (12,000 Btu/h)
Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources, 2021
Typically, the mechanical contractor is to perform their own calculations for the right sizing of equipment to be installed in the house based the building envelope characteristics in place at the time of the HVAC system installation, including upgrades that the homeowner is committ