Greenhouse Design Principles

I am thinking again of moving closer to the design of the Daylesford Longhouse (see my blog post about it here)

My concern is that a greenhouse-like structure with translucent walls may be appropriate to the climate in Victoria, Australia, but may not work so well in a climate with extremes such as the Catskills in New York. Summers are hot and winters are freezing. In the winter icy wind blasts across our site from the plain to the west of us.

Below is my research on keeping Greenhouses cool in the summer:

10 tips for keeping your greenhouse cool this summer

The Summer Sun is Overheating your Greenhouse - Here's How to Cool it Down

7 Ways to Keep Your Growing Dome Greenhouse Cool

This Google Search has great collection of images for Natural Ventilation

Below is research on keeping Greenhouses warm in winter:

7 Tricks for Keeping the Greenhouse Warm Without Using Electricity

Google Search for Solar Greenhouses

Mother Earth News: How to Design a Year-Round Solar Greenhouse

Electrical Power from the Sun

I found an interesting article on the variety of approaches to generating electrical power from the sun in ArchDaily.

Here is a post on incentives for solar in NYS

Hunter Hill PassiveHaus - the Basics

So I am going to use the current design for our Hunter Hill House country home as the basis for determining Passive House criteria.

Passive House Calculations start with area calculations of iCFA (Indoor Conditioned Floor Area) and Exterior Envelope (including foundation slab).

iCIFA Calcs

The ground floor area, exclusive of garage, is 2,700 SF (75ft x 36ft)

The loft level (inclusive of mechanical and storage) is 1,075 SF of space with a headroom greater than 7 feet.

The total iCFA is 3,775 SF.

Exterior Envelope Calcs

The footprint of the occupied building is 3,150 SF (36 ft x 87.5ft)

The north and south wall total surface area is 1,500 SF (75ft x 10ft x 2)

The east and west wall total surface area is 1,044 SF (36ft x 14.4ft x 2)

The roof area is 3,500 SF (20ft x 87.5ft x 2)

The total Exterior Envelope Area is 9,194 SF

Exterior Envelope Area / iCFA = 2.44

iCFA / Persion = 943.75

PHIUS Data

The nearest PHIUS data is for Monticello, NY, which is 25 miles from our site. Our site has an elevation of 2,200 ft; Monticello has an elevation of 1,400 ft. The 800 ft elevation difference will undoubtedly have an impact on these values.

Sample R Values for Climate Zone 6

On page 19 of The Phius + 2018 Passive House Standard Certification Guidebook v2.1 they indicate the following guidelines for R value ratings for Climate Zone 6:

Wall: R-39 to R-51

Roof: R-70 to R-90

Slab: R-28 to R-40