GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Air to water heat pump (or other recommendations) – Minnesota home

rbcat25| Posted inGreen Building Techniqueson

Hello – I purchased an older home last summer southwest of Minneapolis (zone 6). The original slab on grade portion (1 story, vaulted ceilings with no attic – about 1100 sq ft) was built in 1956 (includes 1 office, a bedroom/bath, living room, kitchen). An addition was added on one end of the home in the early 1980s – additional family room, laundry room, and upstairs bed/bath – about 800 sq ft). There is a boiler room below a portion of the addition (about 7 feet tall, concrete ceiling), with a crawl space under the remainder (about 3 feet high). The house has hydronic baseboard fin heat and no air conditioning. There are two zones of heating – one that covers the original area, with a second that covers the addition (including the boiler room and crawl space)

我开始改造旅程并将值列表e any and all guidance/thoughts on what I’m consider. Thus far I’ve ripped off all of the old siding and housewrap – I’ve flashed around all windows/doors, filled obvious gaps, re-wrapped the house, and re-sided. However, there’s a lot left on the journey as the entire layout/house will likely be touched. Given the layout changes and my desire to use most of the wall areas for cabinets or furniture, I would very much like to get rid of the baseboard fins – they are old, noisy, and would need to be replaced soon regardless. Thus I’m considering retrofitting in-floor radiant heat (there is no current ducting and the home design really doesn’t allow for it easily). The boiler is natural gas, was replaced in 2014 or 2015 – runs with a glycol mix. I have a separate gas water heater.

My questions:
– should I consider a air to water heat pump that handles heating and cooling? If so, would a ERV and/or dehumidifier be sufficient to prevent condensation on humid summer days? Would I be able to tie-in the existing boiler to supplement heat on cold winter days? Are there any straightforward guides on how to design the in-floor radiant system?
– As I renovate the home I expect to find 2×4 framing – what types of insulation should I use? I’m considering spray foam as I’m intrigued by the vapor barrier properties (I’m quite certain areas of the home are not sealed properly – especially the upstairs ceiling).
– for the infloor retrofit – I’ve read I should add vertical rigid foam insulation on the outside of the slab. If I added horizontal rigid foam above the slab (inside) but below the PEX, and also spray foamed the walls, is there still benefit to adding the vertical rigid foam outside?
– if a heat pump doesn’t make sense, I would consider mini-splits for cooling. Is it better to go with one large unit and run longer refrigerant lines, or should I install two units to limit the line runs (the way the house was built makes it long and skinny – please see layout)?

I apologize for the long post – any assistance would be appreciated. Thanks.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. William Hullsiek||#1

    Greetings from White Bear Lake, Mn!

    NG boilers and air to water heat pumps are complementary. A system can be designed to automatically switch between the two. Would recommend having a third party doing a Manual J which is a heat loss calculation.

    We replaced all of our hot water fins with Warmboard. Applewood Remodelers in WBL did the work. Very happy with the outcome.

    https://www.applewoodremodelers.com/birchwood-renovation

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |